There are 14 technical session topics listed below. Your abstract/paper should reflect the research or topics as described in the technical session
descriptions as provided.
Tuesday April 4 - Morning Sessions
TRACK A:
Protection of Vulnerable Road Users and Child Occupants
Protection
of children, pedestrians, and bicyclists from injury due to crashes continues
to attract worldwide attention. For children, test procedures for assessing
child restraint system side impact performance and ease-of-use, use of child
dummies in consumer vehicle test programs, and new research into rear seat
performance in crashes has raised considerable attention to child safety
issues. Papers for the child safety portion of this session should focus on
these issues, methods, or data that can further the protection of children in
vehicles. Pedestrian and cyclist protection has been the focus of research
worldwide in recent years. Much progress has been made in this area but additional challenges remain. Attention has
also been placed on improving the frontal structure of passenger vehicles to
mitigate head injuries and improving lower extremity injuries. Many consumer metric programs have implemented rating systems to
encourage deployment of these crash mitigation solutions. Despite these
efforts, pedestrian safety continues to be a severe problem in
several countries. Papers are invited in this session focused on
crashworthiness solutions being designed and offered to address the many issues
faced by children, pedestrians, cyclists, and other vulnerable road users.
TRACK
B:
Safety
Performance in Frontal and Rear Crashes
Despite
reductions in overall crash-related death and injury, frontal impacts continue
to result in the highest numbers of fatalities and injuries. Rear end
crashes are the most frequent type of crash that
occurs. Car and truck manufacturers have made significant improvement in
crash protection over the last four decades, however new test
requirements and ATDs can enhance occupant
safety assessment in frontal and rear end crashes. Changing vehicle
fleet mix characteristics with expanding adoption of alternative
fuel powered vehicles challenge manufacturers to rethink vehicle
design and how to manage crash energy. The session will examine how
vehicle and crash characteristics affect restraint design and overall occupant
safety. Papers are invited to discuss safety issues for frontal and rear crash
protection that are being investigated through modeling, testing, or data
analysis. Session papers may also include various aspects of frontal crash compatibility,
full frontal and oblique safety countermeasures, test devices, test procedures,
and performance requirements.
TRACK
C:
Active Safety Systems for
Crash Avoidance: New Systems and Technologies
Active safety systems
focused on crash avoidance, are continuing to advance in both capability and
market share with systems proliferating across product lines from luxury to
value- focused brands—and even becoming standard equipment in some models.
Active safety systems include longitudinal and lateral warning systems (such as
forward and rear collision warning, lane and roadway departure, and blind-spot
warning), automatic emergency braking or steering, dynamic brake support,
lane keeping assist, and rear visibility systems. In addition,
opportunities for additional crash avoidance potential exists with the
emergence of new technologies and systems addressing opposite direction crashes
(head-on collisions), intersection (crossing path) crashes, enhanced
rear backover avoidance (rear auto
braking), enhanced lane change/merge avoidance through blind spot intervention
systems, and pedestrian and bicycle detection and avoidance through enhanced
automatic emergency braking systems.
Papers are invited on
research for active safety systems, particularly newly emerging
technologies and systems designed to provide improvements in active safety
functionality for crash avoidance. Specific areas of
interest include, estimates of potential safety benefits,
results from real-world evaluations such as field tests, long-term adaptation and reliance issues, as well as other
vehicle integration, testing, system performance, future product development
and customer use considerations.
Tuesday April 4 – Afternoon Sessions
TRACK
A:
Advances
in Experimental and Mathematical Biomechanics and Human Injury Research
The
study of human injuries is essential to continued improvement in
occupant and vulnerable road user crash protection. Detailed
field data analysis to support an enhanced understanding of the factors
associated with injury outcomes, experimental data collection and analysis, and
development and application of advanced physical and mathematical tools, all
play a role in advancing occupant protection. This technical session
seeks papers that address: (1) advances in assessing patterns and causation of
injuries in real-world cases; (2) experimental and analytical studies
addressing human response and injury mechanisms; (3) development or improvement
of human body computational models, including considerations for human
variability in anthropometry, stature, age, and injury tolerance; (4)
application of human body models in the development of advanced/adaptive
vehicle safety systems; (5) advances in development of injury risk curves,
injury criteria, and performance specifications for use with ATDs and
computational models in evaluating vehicle and restraint performance; and (6)
human response, injury mechanisms, and considerations for non-conventional
interiors in vehicles with Automated Driving Systems.
TRACK
B:
Safety
Performance in Side Impact and Rollover Crashes
Side
impact crashes continue to account for a significant percentage of
crash fatalities and injuries worldwide. The introduction
of more biofidelic side impact test
dummies, instrumentation, and new test conditions provide new
performance targets to enhance occupant safety in side impact
crashes. New safety countermeasures have been investigated to reduce
occupant kinematics in far side crashes. Additionally, while advanced
vehicle control and safety technologies have made great strides in
reducing rollover crashes, rollover-related deaths still represent a
significant portion of the overall fatalities and injuries. Panoramic
sunroofs are raising concerns of ejection risks through roof
openings. This session invites papers related to understanding
considerations for new test conditions, performance measures, and the
changing worldwide crash environment for side impact and rollover
crashes.
Driving automation systems (SAE
levels 1-5) continue to evolve and could eventually become
one of the most exciting and important innovations in transportation
history. Significant research, development, and testing activities are
ongoing worldwide to facilitate their safe deployment. Approaches to building
public acceptance, trust, and confidence remains to be among the most important
challenges. This session invites papers related to the current state of
technology development, new safety metrics; system performance testing and
evaluation approaches including utility of track, simulation, and on-road
testing; next generation test tools and methods to perform tightly coordinated
multi-vehicle scenario tests safely; approaches to addressing the challenges
associated with handling a variety and volumes of driving data; approaches to
identifying minimum datasets and data trigger points to validate assumptions and
confirm performance expectations; approaches to assessing the common
sub-functions of driving automation, such as localization, perception,
prediction, path planning, etc. independently; and electronics systems safety
(functional safety, safety of the intended functionality) and
cybersecurity.
Wednesday April 5 - Morning Sessions
TRACK
A:
Advances
in Crash Test Dummies, Instrumentation, and Data Analysis
One
way to enable additional occupant protection opportunities is to develop
new ATDs that are more human-like and have enhanced instrumentation.
Several new, advanced dummies are in varying stages of development around the
world. Dummy development includes assessments for biofidelity, durability, repeatability, and
reproducibility, as well as considerations for new analytical
techniques to evaluate and improve dummy biofidelity.
This technical session seeks papers that address all aspects of advanced dummy
development and application, including new dummies, improvements to
existing dummies, as well as related instrumentation and analytical techniques
that are under development to address future safety needs for vehicle design,
testing, and restraint system development. In addition, papers
addressing development and application of computational models of dummies to
address safety concerns are sought.
TRACK
B:
One
Step Ahead Integrated Vehicle Safety Technologies
This
session seeks papers regarding research on new safety systems that can
anticipate and react to potentially hazardous situations across the entire
crash spectrum. These systems integrate information and sensor data, among
others, from advanced driver assistance systems (ADAS), from automated driving
functions (ADFs), from vehicle-external sources such as the infrastructure and
use this awareness to optimize largely occupant and vulnerable road user
safety. New vehicles with advanced technology are increasingly better
aware of the environment around and within the vehicle and can inform/adjust
and/or intervene with other systems in or outward of the vehicle. Vehicle
designs that include ADFs anticipate new occupant compartment seating
configurations and seating postures. A fusion of sensor data can optimize
vehicle response, change occupant posture, and (adaptive) restraint performance
as needed to enhance occupant safety. Post-crash telematics could inform first
responders of specific vehicle and occupant factors that would assist in triage
and level of response. Papers are sought to describe systems under development,
pioneering system innovations, opportunities for sensor fusion,
interdisciplinary system communication means, system readiness, cost,
reliability, performance, and post-crash response.
TRACK
C:
Human Factors
Considerations for ADAS and ADS Technologies
The success of Advanced
Driving Assistance Systems (ADAS) and Automated Driving Systems
(ADS) vehicles will depend on the quality of human-machine interface
(HMI), adapting ADAS and ADS to human capabilities
and safety needs and potentially the system's ability
to manage the driver's state of attention appropriately. There
has been extensive work on HMIs for ADAS systems, including auditory alerts,
haptic alerts, visual alerts, and many combinations of those three. Driver
monitoring capabilities enable real time adjustments to warning parameters when
drivers are identified as being disengaged, distracted, drowsy, or otherwise
impaired. In addition, ADS could take advantage
of using the driver's estimated engagement state for
safe transition of control back to the driver. Papers are invited on
research related to the driver-vehicle interface for crash avoidance
systems, safety evaluation methods for assisted and automated
driving, driver monitoring technology, driver behavior and engagement patterns and
estimation, fatigue drowsiness, distraction, and other impairments, and how
they relate to ADAS and ADS. In addition, for ADS technologies, particularly
those without traditional controls, papers are invited on additional topics
such as external signaling to other road users, as well
as telltales, and other signaling that may be useful for
occupants of ADS vehicles, and human factors design needs for
vulnerable and disabled users of ADS vehicles.
Consumer-Focused
Approaches to Promote Vehicle Safety in the Automotive
Market
Consumer
information programs have become widely accepted in the U.S., Europe, Japan, Australia,
Korea, China, Latin America, and Asia. These
programs provide a range of vehicle safety ratings for
passive and active vehicle technologies. The motor vehicle
industry continues to improve the safety performance of vehicles as it strives
to receive the highest safety marks possible. In addition to assessing
occupant crash safety, programs are emphasizing advanced driver
assistance systems and considering approaches
for automated vehicle technologies. While assessment strategy varies
from region to region, the programs all aim
to encourage continuous improvements in
motor vehicle safety. Papers are invited to discuss test conditions,
performance measures, presentation and dissemination of results, public
acceptance, promotion of safety relevant mental models for the
new driver roles. Automated Driving Systems (ADS) bring along an
integration of active and passive safety ratings and the increasing
importance of virtual testing.
TRACK
C:
Opportunities and
Challenges of Applying Artificial Intelligence (AI) and Machine
Learning Techniques to Enhance Vehicle Safety
Artificial intelligence
(AI) and machine learning approaches hold potential
to synthesize large amounts of unstructured data to learn
and address hard problems and are rapidly being explored across
a variety of industries and use cases. AI is also among the most
misunderstood and erroneously cited fields of study. This session invites
discussions around what AI means in the automotive context, how AI
algorithms differ from traditional, complex software systems, and what parts of
automotive systems are more likely to leverage algorithms that could be
considered AI, and whether AI is expected to be used primarily in development
stages or could also be deployed. Further, papers are invited to discuss
challenges associated with and methods that could enhance the verification
and validation of AI systems in automotive applications.
Thursday April 6 – Morning Sessions
TRACK
A:
Developing and Adapting
Safety Assessment Approaches for Vehicles with
ADS (SAE Levels 3, 4 and 5)
Existing vehicle safety
regulations, test procedures, and performance requirements were all
developed in an era when all vehicles featured manual
driving controls. The development of ADS enables vehicle designs without manual driving
controls and necessitates reconsideration of certain existing
regulations, test procedures, and performance requirements. A vehicle
with an ADS might be designed without user interfaces, such as braking, acceleration,
steering, or transmission gear selection. Test procedures that
presume existence of traditional driving controls may need to
be reconsidered. The presence of delivery vehicles without
occupants also needs to be considered for the future roadway
environment and infrastructure. This session invites papers that discuss
how regulations, test procedures, and performance measures could be adapted or new approaches developed, to encompass the
vehicles with ADS designs under consideration. Further, this session
invites papers on new approaches to assuring safety of ADS, including test
tools, test methods, alternative safety metrics, and alternative
frameworks.
TRACK
B:
Restraint
System Design and Performance Challenges: Addressing the Needs of Diverse
Populations (Age, Gender, Stature)
Vehicle
restraints in frontal crashes are estimated to be approximately 50 percent
effective in preventing fatalities. Occupant protection can be improved through
the development of advanced restraint systems that can consider occupant
characteristics such as age, gender, size, and posture, as well as the
anticipated crash characteristics. Concerns also exist for restraint design
with respect to future vehicles that may be smaller and/or lower in mass to
improve fuel efficiency. The aging population will be an increasing
consideration for restraint design. Adaptive protection systems will be needed
to optimally protect an increasingly vulnerable occupant population. Rear
seating positions have not demonstrated the same improvement as the front
seats. These issues are receiving the attention of safety researchers
world-wide. Papers are invited on research related to safety performance for
new vehicle and restraint designs, especially as they pertain to older
occupants, small females, and heavier populations.
TRACK
C:
New
and Improved Field Data Collection, Analysis, and Benefits Assessment
Methods
Use of
crash data helps to stimulate all aspects of vehicle safety from research to
policy to regulationand
research testing. These data also play a leading role in the development of
crash prevention and crash protection countermeasures. However, due to
the rapid proliferation of advanced vehicle technologies, the
collection and analysis of data from these technologies needs to evolve
to better understand the real-world performance and to quantify the
benefits and limitations of these technologies. Data collected on event data
recorders (EDRs), other data loggers, or over-the-air for close calls or near
miss crash events will likely enable new research opportunities. Also,
several naturalistic studies and testing of Automated Driving Systems
(ADSs) are in progress in various regions of the world that will provide
additional insight into how crashes occur, providing additional information on
prevention. Worldwide, data collection programs in Asia, Europe, Australia, and
the U.S, are being used more to drive research and facilitate
informed decisions. This session invites papers aimed at a discussion of
future data collection and analysis methods. Papers related to such topics as
EDRs, naturalistic driving data on human-vehicle performance, crash avoidance
technologies, and all levels of driving automation, and crash
reconstruction are welcome in this session. Also, papers on analytical methods for estimating potential benefits of safety technologies, evaluation methods of video data, universal descriptions of crash causal factors and resulting crash types, and other related topics are invited.
Tuesday, April 4, 2023, | 08:30-12:30
Chair: Suzanne Tylko, Canada | Co-Chair: Yasuhiro Matsui, Japan
TRACK A | Room: G303
Paper No.23-0025-O
Analysis of the effect of reducing accidents involving
pedestrians through the coordination of active safety and passive safety
Yuichi Omoda, Yuji Arai, Kazunori
Kikuchi, Ryohei Homma, Hisashi Imanaga Japan Automobile Research Institute, Japan Nobuhiko Takahashi Japan Automobile Manufacturers Association, Japan
Abstract
In order to efficiently reduce traffic
fatal accidents, it is important that all parties involved in traffic safety
(traffic participants, road infrastructure, and vehicles) work in unison to
implement countermeasures. For this purpose, it is necessary to analyze the
reduction effects of vehicle safety measures, the limitations of vehicle safety
measures, and the accident patterns that remain after the vehicle safety
measures are taken. In this study, the fatal accident reduction effect of
vehicle safety measures combined with active and passive safety technologies
was estimated for the accidents involving pedestrians, which are the most common
type of fatal traffic accidents in Japan. In addition, the characteristics of
fatal accidents in which vehicle safety measures are not currently addressed
are summarized. First, we estimated the extent to which pedestrian fatalities
can be reduced through the AEB for pedestrians and improvement of pedestrian
head protection performance. For the remaining fatal accidents, we estimated
the number of fatal accidents that could be reduced by expanding AEB functions
(additional fatal accident reduction effects are expected by increasing AEB
corresponding scenarios) and by other vehicle safety measures (advanced
emergency steering systems, etc.). This clarifies the extent of fatal accidents
that have not yet been addressed by vehicle safety measures. This study used
accident data collected by the Japan Institute for Traffic Accident Research
and Data Analysis (ITARDA) from year 2015 to 2017. The analysis assumed a
vehicle safety measure penetration rate of 100%. It was found that the number
of fatal accidents could be reduced by 20% and 29% by the AEB for pedestrians
and improving the performance of pedestrian head protection in the daytime and
nighttime, respectively. It could also be observed that AEB function expansion
and devices other than AEB covered approximately 38% and 23% in the daytime and
nighttime, respectively. The results suggest that the accident reduction effect
of AEB for pedestrians is significant, but that 42% and 48% of accidents are
left behind even when the functional enhancements of AEB and other vehicle
safety measures are added up in the daytime and nighttime, respectively. To
further reduce the number of accidents left behind, it is efficient to promote
not only vehicle safety measures but also measures for the society as a whole.
Paper No.23-0042-O
An overview of road traffic injuries among children in
Sweden over 20 years
Maria
Klingegård, Anders Kullgren,
Helena Stigson, Anders Ydenius Folksam Insurance Company, Sweden
Abstract
This register study, focusing on
children from (0-17 years), aimed to investigate traffic injuries (AIS1-5)
among children on roads in Sweden between 2000 and 2019. The Swedish national
database (STRADA) was used. It includes road traffic crashes reported by the
police and by emergency care centers. The data included road user group, age,
gender, injury type, AIS level, and use of seatbelt or child restraint.
Descriptive statistical analysis and simple linear regression were performed to
investigate significant changes in injury distribution between 2010 and 2019. A
total of 14 731 registered crashes during the last 20 years involved 15
045 injured children (0-17 years). Six thousand six hundred forty-three
were girls and 8088 boys. The total number of injuries decreased over time (40%
since 2010). Most injured children (80%) sustained minor injuries (AIS1). Most
were 12 to 17 years old (80%). A change in injury distribution was found
according to age; for 0-9-year-olds, most injured children were pedestrians,
while for 9-13 years old's, bicyclists were most common. For 14-16-year-old
children, moped riders were most common. Most injured children (62%) were
vulnerable road users (2000-2019). A 15% increase in the proportion of injuries
between 2010 and 2019 was found. A 24% decrease in the proportion of injuries
for children as vehicle occupants (excl. motorcycle and moped riders) between
2010 and 2019 was found; still, in 2019, 35% of the injured children were
vehicle passengers. The most frequently injured body region was the head (26%),
followed by the neck (19%). Eleven percent of the injured children in cars were
unbelted. Twenty-two percent of the 0-12 years old children did not use a
proper child restraint. The study confirms that Sweden's traffic safety for
children (0-17 years) has improved since 2000. A 40% reduction in the number of
injuries was found between 2010-2019 (including minor injuries that account for
80% of all reported injuries). The study also highlights that for vulnerable
road users, the proportion of child injuries (0-17 years) increased by 15%,
which was lower than vehicle occupants (24% decrease). Moped riders account for
the largest road user group (35%) (2000-2019). Therefore, it is important to
improve protection for children as vulnerable road users both regarding severe
injuries as well as minor injuries leading to long term consequences for a safe
(sustainable) traffic environment.
Paper No.23-0144-O
Development of a standard for deployable pedestrian
protection systems (DPPS) for Amendments to UN Global Technical Regulation No.
9 and UN Regulation No. 127
Oliver Zander German Federal Highway Research Instutute
(BASt), Germany Irina Dausse Renault, France Peter Martin National Highway Traffic Safety
Administration (NHTSA), United States Jin Seop Park Korea Automobile Testing & Research
Institute (KATRI), Korea, Republic of
Abstract
World-wide test and assessment
procedures for passive pedestrian protection have been in place for many years.
Passive safety requirements within UN-GTR9 are prescribed through tests to the
front ends of stationary vehicles with instrumented impactors representing the
pedestrian's head, pelvis, and lower extremities. However, no specific
requirements are included for vehicles equipped with deployable pedestrian
protection systems (DPPS). This paper describes the work of the UN informal
working group (IWG) to develop procedures on DPPS that are intended to be
incorporated into UN-GTR9 and UN-R127 as amendments. DPPS must work as intended
during actual vehicle-to-pedestrian accidents. Therefore, test methods and
conditions need to reflect the challenges DPPS are facing during actual and
representative accident scenarios, but without being design restrictive.
Several prerequisites need to be met to assure that DPPS operate properly and offer
at least the same level of protection as conventional passive pedestrian
protection systems. These prerequisites include system requirements providing
pedestrian detection and the timely and safe DPPS deployment. Also, headform
tests are run at impact speeds below the DPPS deployment threshold on the
undeployed system to confirm the undeployed bonnet is sufficiently safe. Draft
amendments intended for UN-GTR9 and UN-R127 are being finalized by the IWG on
DPPS to harmonize testing under the agreements of 1958 and 1998 while
preserving contracting parties' options for domestic standards. Results
reported herein include IWG investigations of: (1) An appropriate impactor to
assure pedestrian detection by the front-end sensing system; (2) Real world
pedestrian accidents to determine the needed detection test area width; (3)
Qualification procedures for Human Body Models (HBM) to determine head impact
times (HIT) and impact locations; (4) An empirical formula to determine HIT in
lieu of HBM simulations; (5) Experimental determination of the total response
time of the DPPS. Altogether, the amendments provide for headform impact test
conditions on DPPS against established performance requirements to reduce head
injury risk. A DPPS is expected to offer a sufficient level of pedestrian
protection while preserving vehicle design freedom. Several shortcomings of the
developed procedure are discussed, and limitations identified which could
reduce the actual pedestrian protection during a crash: The FlexPLI does not mimic
the hardest to detect pedestrian. The detection test area does not fully
account for all pedestrian impact trajectories. The bonnet clearance afforded
by a DPPS could be compromised by the upper body load. The deployment height
and the oncoming speed of the deploying bonnet could differ between testing and
real-world scenarios. A valid HIT determination using a HBM simulation on a
given vehicle model requires good CAE correlation with the actual vehicle.
Experimental testing or an empirical formulation to determine HIT, could
increase objectivity. The draft procedures are being developed by the IWG for
consideration as amendment to UN-GTR9 and UN-R127. It will offer an approach
for compliance testing of vehicles equipped with DPPS. Since UN-R127 and the Euro
NCAP have extended their scopes to the head protection of bicyclists, the DPPS
head protection potential should be investigated accordingly in future studies.
Paper No.23-0155-O
A study on distractions and benefits of signal light
projections with directional indicators
Haeran Kang, Hyensou
Pak, Han Eol Seo, Na Hyun Kim, Jemok Lee, Chan-Su Lee Yeungnam University, Republic of Korea
Abstract
To prevent accidents, the signaling
function of automotive exterior lighting is essential to provide other road
users with information on the presence of the vehicle and/or changes in its
moving direction. Recently, dynamic turn signal indicators, backup indicators,
and other light projections with directional indicators have been proposed and
studies are being conducted to evaluate their safety enhancement and visibility
in different lighting conditions. However, previous studies had limitations
since most of them had not been studied or verified under dynamic driving
situations. In addition, there aren't any studies on the distraction caused by
turn signal projection lamps. Therefore, it is necessary to provide an
assessment of the distraction and benefits of turn signal projection lamps
under several dynamic scenarios. For this reason, we investigated whether the
signal projection lamps, which work simultaneously with directional indicators
and project a simple geometric pattern of a certain color and size on the left
and right road surfaces in front of the vehicle, are beneficial or distracting
to other drivers and VRUs (Vulnerable Road Users) such as cyclists and
pedestrians. Twenty participants participated in the experiment. The results
showed that the signal projection lamp hardly distracts drivers, cyclists, and
pedestrians, but rather helps predict the presence of oncoming vehicles and the
moving direction of the vehicles. Particularly with the signal projection lamp,
the cyclist test showed a 14% and 9% decrease in detection time when the
vehicle turned right and left, respectively. These differences were
statistically significant. Our results suggest that a signal projection
lamp is more beneficial than a distraction to drivers, cyclists, and
pedestrians.
Paper No.23-0187-O
Real-world protection of booster-seated children – Needs
and challenges in future transportation
Lotta Jakobsson,
Katarina Bohman, Isabelle Stockman Volvo Cars, Sweden
Abstract
Driven by sustainability goals,
passenger cars' design and ownership setups are changing. Vehicle safety is
constantly improving, yet a trend of larger belt-positioning boosters is seen.
The objective is to discuss the challenges of child passenger protection in the
current and future mobility context. The study focuses on children who can use
the vehicle seatbelt together with a booster, typically 4 to 10-12 years. The
study is based on protection principles of booster-seated children, with a
vehicle-booster-user entity focus. Studies on restraint awareness and usage
today, users' perceptions on future mobility and evolutions of vehicle design
and mobility trends, are summarized and reflected on. Real-world protection
needs are formulated based on in-vehicle crash testing/simulations, and studies
on child passenger sitting postures during drive and evasive maneuvers. This is
put in the context of regulatory and booster development trends. In a
real-world crash, children are protected by the vehicle and booster in
combination. Crash tests/simulations highlight the importance of the seatbelt
interaction, influenced by initial beltfit and the dynamic properties of the
booster. On-road driving studies show that awake child passengers spend a
non-neglectable duration of the trip with a forward head position, due to
visibility and activities. A forward head position could also be a result of a
pre-impact braking as well as the added space by the booster seat's backrest.
In case of a frontal impact, a more forward head position at time of impact
will result in a more forward excursion. Real-world side-impact data shows that
the booster-seated child's head is protected like an adult, assisted by the
vehicle safety systems. The booster serves as an adapter, not as a
primary restraint for the child. Booster-seated children benefit from the
vehicle safety systems, given they are raised in position for good beltfit and
posture. Addressing the changing trends of passenger cars' design and ownership
setups, the role of the booster should be clearly communicated. Future designs
must address issues of usability, portability, and acceptance. As examples, the
streamlined roof designs driven by sustainability goals, reduce the roominess
in the rear-seat, whereby the booster seat backrest's width and height might
require larger space than needed for an adult; and the trend from personal
mobility towards increased degree of shared mobility, emphasizes the need of
the booster to be portable or integrated into the vehicle. Real-world child
passenger safety involves protection aspects beyond standardized crash testing
scenarios. Most importantly, the booster should be used in every trip, irrespectively
of passenger car ownership setup. This study provides insight into modern
vehicles' protection capacity in relation to the booster-seated children. It
outlines some areas that are affected by the current booster developments, such
as the increased size and complexity of booster seats, and the booster cushion
ban in some parts of the world. In relation to the current and future
transportation context, a booster cushion with appropriate characteristics
serves as an essential complement to booster seats (of reasonable size) and
will help maintain a positive child safety global trend.
Paper No.23-0189-O
Accident simulations of a novel restraint safety concept
for motorcyclists
Steffen Maier, Jörg Fehr Institute of Engineering and Computational
Mechanics, University of Stuttgart, Germany
Abstract
Except for personal protective
equipment, riders of powered two-wheelers are currently unprotected when
impacting into an accident opponent. This work investigates a motorcycle safety
concept that proposes a combination of thigh seat belts, airbags, and leg
impact protectors. It gives a virtual prediction of the accident behavior using
finite element models of the motorcycle with passive safety systems, an
accident opponent, and an anthropometric test device as a rider surrogate in
recommended frequent accident scenarios. It shows a meaningful graphical
description of the functional and causal principles of a powered two-wheeler
rider restraint and a quantified performance evaluation of the concept. The
combination of several passive safety systems has shown to be promising in
positively influencing accident behavior and mitigating consequences.
Paper No.23-0211-O
Activating global collaboration to drive advancements in
child restraint systems for children with disabilities
Helen Lindner, Emma Clarkson Mobility and Accessibility for Children in
Australia Ltd, Australia
Abstract
Research shows that children with
disabilities face an increased risk of injuries and fatalities in a crash
compared with other children. However, a recent literature review concluded
that these particularly vulnerable road users continue to be inappropriately
restrained in vehicles, constituting an ongoing road safety problem. This also
impacts on their human right to safe and accessible transport. Although
globally, there are established independent assessment programs for child
restraint systems, there is no such program for special purpose child
restraints or other restraint types used by children with disabilities. With
the formation of a new Australian charity dedicated to advancing the rights of
children with disabilities to safe and accessible transport, the objective of
this project is to enhance the protection of children with disabilities
travelling in child restraint systems in motor vehicles through the
establishment of an independent safety and assessment program. The
development of the Australian Safety Assessment Program (AuSAP) was supported
with funding from the Victorian Transport Accident Commission, and in-kind
support from NeuRA and Britax. A mixed methods research approach was used,
consisting of: Desktop review - A review of the legislative and regulatory
environment impacting on the supply, sale and use of special purpose child
restraints and accessories in Australia was conducted. A global product scan
identified restraints for inclusion. Governance framework - Several governance
framework options were developed, with the recommended option being a
not-for-profit lead agency model supported by an Expert Committee. Protocols - The
Expert Committee developed the Test and Assessment Protocol based on a review
of standards/regulations. Assessments/crash testing - Fifty-four crash
tests have been undertaken (forward and side impact testing), with results
shared with relevant suppliers and manufacturers. Communication/education -
MACA is developing individual Product Guides that incorporate AuSAP findings to
support allied health professionals in their prescribing role. AuSAP is
implementing a global approach to improve motor vehicle restraint systems for
children with disabilities in line with therecommendations
in the World Health Organization's global report on Assistive Technology and
the Convention on the Rights of Persons with Disabilities. The program
has rapidly stimulated the Australian market to supply special purpose child
restraints by increasing the confidence of suppliers, prescribers, consumers,
and government funders. This has expanded safe motor vehicle transport
options for children with disabilities. It has also provided a unique
opportunity for global collaboration with manufacturers to improve the design
and safety of restraint systems for children with disabilities. AuSAP has
facilitated international engagement about the suitability of current
requirements in standards/regulations for special purpose child restraints and
consideration of potential improvements for future reviews. This has the
potential to remove barriers to access not only in Australia but globally. The
first program of its kind, AuSAP has achieved early success in encouraging
international cooperation and learning to advance the human rights of our most
vulnerable road users to safe and accessible motor vehicle transport. Access to
such life changing assistive technology is a precondition for equal
opportunities and participation.
Paper No.23-0217-O
Simulation-based evaluation of a generic Autonomous Emergency
Braking system using a cognitive pedestrian behavior model
Lucas Fonseca
Alexandre de Oliveira, Lars Schories ZF Friedrichshafen AG, Germany Lukas Brostek cogniBIT GmbH, Germany Martin Meywerk Helmut-Schmidt-Universität, Germany
Abstract
In 2020 pedestrians accounted for
21,4% of all deaths in the European Union. Considering all vulnerable road
users (VRU: pedestrians, cyclists, motorcycles, and mopeds) they accounted for
51,4% of all deaths. To reduce the number of deaths and improve VRU safety,
systems have been developed in the last decades. The autonomous emergency
braking system (AEB) is one of these systems and aims to intervene in conflict
situations by applying an emergency braking (in some cases only after the
driver starts the brake itself). The performance evaluation of an AEB system
via simulation reduces cost and time against real tests and allows better
robustness evaluation because of the higher number of scenarios that can be
simulated. In the virtual-world, safety-critical situations can also be tested
without any problems. The modeling of pedestrian behavior plays an important
role since the pedestrian is the vehicle's adversary in this context. Current
studies use a simple pedestrian model, in which the pedestrian does not have
any perception of the environment, moving on a pre-defined path with constant
speed. Such trajectory-based models are available in the most common vehicle
dynamic simulation tools. In reality, however, pedestrians usually react to the
approaching vehicle in conflict situations by adjusting their trajectory, which
can change the conflict situation and affect the performance assessment of AEB
systems. This study compares the standard model with neuro-cognitive pedestrian
model from cogniBIT and investigates if and how these models affect the
performance assessment of AEB systems.
Paper No.23-0248-O
Investigation on effects of whole-body kinematics during
collision on pedestrian injuries
Research Question/Objective: Recently,
pedestrian safety performance of vehicles has been improved by the modification
of regulations and new car assessment programs (NCAPs). In particular, safety
performance of the bonnet has been improved in terms of head protection by
reducing HIC. According to the accident statistics, however, pedestrian
fatalities account for a high percentage, and the causes of death include not
only head injury but also thoracic and pelvis injuries. Therefore, pedestrian
protection technologies need to include protection of these body regions in
addition to the head. In order to reduce the number of pedestrian fatalities,
this study aimed to investigate the effect of the whole-body kinematics on
injury reductions of pedestrians.
Methods and Data Sources: In a
collision between a bonnet-type vehicle and a crossing pedestrian, the whole
body moves in a chain reaction starting from the input to the legs,
subsequently transmitted to the pelvis, the thorax, and the head. Therefore, it
is expected that controlled pedestrian kinematics from the time of collision
will have an effect on the injury to various body regions. In this study, the
GHBMC 50th percentile male model and the vehicle model with general bonnet
type was used to simulate car-pedestrian collisions. A model composed of spring
and shell elements was affixed to the vehicle model to apply controlled loads
to the center of gravity of the pedestrian model by changing the stiffness
characteristics of the model, and the relationship between the whole-body
kinematics of the pedestrian model and the injury values was investigated at a
collision speed of 40 km/h.
Results: The results confirmed that
the angular velocity of the upper body around the center of gravity was reduced
by the early input to the pedestrian pelvis, effectively reducing thoracic
input and the head injury value.
Discussion and Limitations: Input to
the pelvis depends on the input through the legs and the external force from
the vehicle. Since the vehicle used in this study had a low bonnet height,
there was little external force from the vehicle to the pelvic region,
potentially diminishing the effect of restraining the center of gravity. Since
this study used a specific collision speed and a pedestrian size, it is necessary
to consider the influence of these factors in a future study.
Conclusions and Relevance to Session
Submitted: This study clarified that pedestrian kinematics control technology
may be one of the effective measures to further reduce pedestrian fatalities.
Paper No.23-0270-O
The "typical" car-cyclist collision under the microscope:
A GIDAS-based analysis of the prevalent crash scenario
Niklas Puller, Gwendal Lucas, André Leschke Volkswagen AG, Germany Oliver Maier, Jörg Mönnich Robert Bosch GmbH, Germany Vittorio Rocco Tor Vergata University of Rome, Italy
Abstract
In a world where reducing the carbon
footprint is crucial, riding carbon-neutral vehicles such as bicycles or
pedelecs is a sustainable and thus desired way of transport. Since motorized
and unmotorized bicycles are missing any protective body, their riders are part
of the vulnerable road users (VRUs). In order to increase the attractivity of
transport by bicycle and pedelec, providing traffic safety for this group must
be ensured. To get a better understanding of cycle crashes, this paper's
objective is to deduce the most important crash types of collisions of cyclists
with passenger cars. By obtaining the characteristic details of these crashes,
strategies for crash avoidance can be derived. The data source used for the
results presented in this paper is GIDAS (German In-Depth Accident Study).
GIDAS is a unique database as the input data is provided by experts on crash
reconstruction who join the police at the crash site and record the crash in
great detail. 8497 relevant crashes involving bicycles, captured from
2000-2021, were evaluated. The methodology consists of the evaluation of the
two most common crash types regarding speed distributions and contact points of
the crash opponents, street layout, driver intent, traffic density, and visual
conditions. The results show that the most common crashes are two crossing
crash types accounting for nearly a third of all crashes between cyclists and
drivers of motorized vehicles. Both of these crash types are characterized by
the cyclist riding on the designated cycling infrastructure, while in the more
common one, the cyclist goes against the expected direction for the crash
opponent. For the selected crash types, the results also show that more than
half of crashes occur at junctions, predominantly where the driver has to
yield. Most crashes occur during turning right maneuvers at low traffic
densities and speeds below 13 kph. The evaluation of the car driver's maneuvers
performed in the last second before the crash indicates a black spot in
driving-off situations. In more than 70 % of the cases, the contact point with
the cyclist is at the front. The data, analyzed in detail in the discussion,
points towards the theory that drivers tend to "fail to look" at cyclists
coming from the right and "look but fail to see" cyclists from the left.
Furthermore, cyclists crossing from the right might not be expected in
right-hand traffic. A general limitation of official crash data sources based
on police reports is a high underreporting rate of bicycle crashes. Using the
German crash database, also certain bias towards countries with similar traffic
infrastructure must also be assumed. This is further analyzed in the
discussion. The conclusions drawn from this study show that cycling
infrastructure remains of the highest importance and needs to be designed in
accordance with the human factor in traffic. Also, communication between
involved parties can contribute largely to tackling the most dominating crossing
crash types, i.e., virtually enhancing the cyclist's visibility for other
traffic participants.
Paper No.23-0273-O
Factors influencing upper neck loading in regulatory
tests of child restraint systems
Costandinos
Visvikis CYBEX GmbH, United Kingdom Christoph Thurn, Thomas Müller CYBEX GmbH, Germany
Abstract
Potential neck force and moment limits
in UN Regulation No.129 are part of on-going regulatory discussions. Pragmatic
limits for the Q0, Q1 and Q1.5 dummies were proposed to regulators in 2020,
based on analyses of type-approval monitoring data. However, chin-to-chest
contact was acknowledged as potentially skewing the analysis and undermining
the proposed limits. The aims of this study were to: 1) investigate the effect
of impact direction and child restraint orientation on neck tension force and
2) quantify the effect of chin-to-chest contact on a large study sample of
child restraint type-approval tests, for all Q Series dummies (Q0 to
Q10). Over 200 official type-approval tests were collected from our
internal database with data extracted for neck tension force and head vertical
acceleration. The head vertical acceleration multiplied by the head mass was
used to calculate the neck tension force due to inertial loading from the head.
This was compared with the measured neck tension force to determine the
frequency of chin-to-chest contact and its likely influence on neck tension
force in type-approval tests. The data were then separated for each Q-Series
dummy by impact direction and child restraint orientation to identify trends
for each test or installation parameter The inertial neck tension force
calculated from head vertical acceleration was lower than measured neck tension
force in almost all front impacts with forward-facing child restraints and in
many rear impacts with rear-facing child restraints. Differences were in the
region of 30-50 percent depending on the dummy and child restraint installation
parameters. This indicated the presence of chin-to-chest contact in a large
proportion of the tests in the sample. Forward-facing child restraints
generated highest neck loads in front impact, whereas rear-facing child
restraints generated highest loads in rear-impact. Our analysis suggests
chin-to-chest contact occurs frequently in child restraint type-approval tests
with substantial influence on neck measurements. This confirms that pragmatic
limits derived for regulation from type-approval data are likely to be skewed
upwards by this contact. Subsequent measurements in future type-approval tests are
also likely to be skewed upwards and hence mitigating chin-to-chest contact may
be incentivised more than limiting inertial neck loading. Although large, our
sample comprised tests from one child restraint manufacturer only. A larger
sample, comprising a broad range of manufacturers, is needed to validate our
findings fully. Nevertheless, this study has demonstrated a robust approach for
such analyses. Child restraints are very effective in reducing the risk of
serious neck injury to children in collisions. Nevertheless, a relatively large
range of neck loads can be measured in type-approval, which can be influenced
by dummy chin-to-chest contact, as well as child restraint installation
parameters. Quantifying these influences will contribute to ongoing regulatory
discussions about the use of neck force and moment limits in UN Regulation
No.129.
Paper No.23-0290-O
Influence of different parameters of vehicle and
pedestrian on chest injury using human body model (HBM)
Chinmoy Pal Nissan Motor Company, Japan Vallabhaneni Pratap Naidu, Vimalathithan
KULOTHUNGAN RNTBCI, India
Abstract
In Japan from 2000 to 2019, the number
of motor vehicle occupant fatalities decreased significantly. Pedestrian road
user type contributes to 37% of total traffic fatalities, the highest compared
to other road user types since 2009. In pedestrian accidents, head, and chest
body regions account for 51% and 40%, covering about 91% of the total AIS4+
injuries, respectively. So, head and chest protection are important elements
for reducing pedestrian fatalities. At present, there are test procedures for
head and lower extremities injury protection, but no test procedure exists for
pedestrian chest protection. BAST has proposed a specific thorax injury
prediction tool (TIPT) developed from side impact dummy ES-2. Based on their
proposal, an adult chest impactor will be impacted by several predefined impact
grid points covering a range from a child's lower rib height (WAD: 770mm) to a
95th_%ile male's upper rib height (WAD:1540mm). Injury criteria for TIPT were
based on injury risk curves of 45- to 67-year-old adults. In this paper, the
influence of different parameters of vehicles and pedestrians on chest injury
using human body models (HBM) and TIPT modules are studied in detail. It can be
concluded that (a) similar to the existing head injury evaluation impactors,
child and adult TIPT impactors need to be different since the biomechanical
characteristics are different (b) based on human body models' CAE simulation
with the target generic vehicles models (GVM), the chest impact velocity is
considerably lower than those recommended values of BASt and (c) it has been
observed that BLE height, bumper lead upper, hood angle are the significant
parameters for the chest impact velocity.
Paper No.23-0309-O
Preliminary study on
crash pulse influence for child ATD response in child restraint systems
Hans Hauschild,
Brian Stemper Medical College of Wisconsin, United States Ian Hall, Allison Louden National Highway Traffic Safety Administration
(NHTSA), United States
Abstract
Different vehicle crash scenarios may
produce different crash pulses dependent on several variables. Crash
simulations utilizing a sled system are more repeatable but may subject anthropomorphic
test devices (ATDs) to different input pulse levels depending on sled type and
its settings. Those different input pulses may influence the test device's
response. The goal of this current study examined different sled pulse inputs
and their influence on child ATDs. ATDs were secured in child restraint systems
on the proposed updated frontal test bench for Federal Motor Vehicle Safety
Standard (FMVSS) No. 213 and subjected to three input pulses with the same
target delta-v (48 kph). All three input pulses were within the FMVSS No. 213
boundaries. Hybrid III 10-year-old and 6-year-old test devices were tested
using four belt positioning booster seats and one forward facing harness seat.
Head, chest, neck, and belt load metrics were examined for coefficient of
variation, trends related to input pulse acceleration increases, and any
significant differences. Examination of the study results indicate that
increased acceleration pulse inputs had the most influence on head
accelerations, chest accelerations, and neck tensions but had little effect on
chest deflections or head and knee excursions.
Tuesday, April 4, 2023, | 08:30-12:30
Chair: Stephen Summers, United States | Co-Chair: Younghan Youn, Korea
TRACK B | Room: G304
Paper No.23-0060-O
Passenger cars in
head-on crashes with heavy goods vehicles: for what severity should future car
restraint systems be designed?
Krystoffer Mroz,
Martin Östling, Nils Lubbe Autoliv Research, Sweden
Abstract Twelve
passenger car-to-heavy goods vehicle (HGV) head-on crash configurations were
simulated to identify which of these crashes lead to the highest crash severity
for the car and are feasible, i.e., with non-compromised compartment integrity,
in order to support the development of occupant restraints in high-severity
crashes. These configurations comprised two impact velocities (car 39 km/h, HGV
36 km/h and car 56 km/h, HGV 53 km/h), two car overlaps (50 and 80 %) and three
impact angles (0, 30 and 30 deg). Generic finite element models of a
1.7-ton car and a 7.9-ton HGV were used to investigate the crash pulse severity
and car compartment structural integrity in all crash configurations; the
results were compared to that of a current standard full-frontal rigid barrier
56 km/h crash. Car crash pulse severity was evaluated at the left sill using
peak acceleration, delta V, cross-zero time, and occupant load criteria, while
car compartment integrity was evaluated by measuring intrusions at the toe pan,
instrument panel, A-pillar, and steering wheel. All lower-severity (39/36 km/h)
crashes were found to be well represented by the full-frontal rigid barrier 56
km/h crash test. For the higher-severity (56/53 km/h) crashes, three out of six
crashes (both -30 deg crashes and the 50% overlap 0 deg crash) were found as
currently too severe in terms of compromised compartment integrity to be used
in the development of new restraint systems. Two high-severity crashes were
identified which can be targeted for new restraint systems development: The
56/53 km/h 80 % overlap 0 deg impact angle crash was determined to be the most
severe in terms of peak accelerations (91 g) and OLC (63 g), and with a high
delta-V (97 km/h). The 56/53 km/h 50 % 30 deg crash was found to be the most
severe in terms of delta-V (105 km/h) and pulse duration in time. Both these
crashes were much more severe than the full-frontal 56 km/h crash. The 56/53
km/h 80 % 0 deg crash was similar in crash severity to a full-frontal rigid barrier
90 km/h crash: we believe this configuration may be worth considering in future
legislation and rating programs, which would immediately facilitate development
of improved restraint system addressing fatalities in high-severity crashes.
PEER REVIEW Paper No.23-0076-O
Load distribution
structure of rear bumper beam to enhance vehicle body energy absorption in
rear-end collision
Atsushi Hasegawa, Norikazu Matsuura, Takayuki Fujii Honda R&D Co., Ltd,
Japan Tomohiro Shimizu BENTELER, Japan
Research
This study
focused on FMVSS301, which is one of the highest energy test standard for
rear-end collisions. Since it is an offset collision, the deformation of the
non-collision side frame, which does not directly contact with the barrier, is
small. The reason is that the rear bumper beam with curvature is deformed into
straight shape by the load from the barrier, resulting in an asymmetrical load
distribution from the barrier that is biased toward the collision side.
Therefore, the objective of this research was to construct a new bumper beam
structure that reduces the difference in the load input to the left and right
frames and increases the energy absorption of the non-collision side frame.
Methods
The concept is to
keep the load input from the barrier symmetrical to the rear bumper beam. To
achieve this, the overall profile of the rear bumper beam was given a
trapezoid-like shape, with straight portion at the center which overhangs
rearward from both ends where it joins with the rear frames. A time difference
is created before the barrier and the beam ends make contact, thereby limiting
the area of load input from the barrier to the central flat area. The
cross-sectional strength was designed to retain the profile and to maintain
symmetrical input conditions even in high load ranges. Based on a C-category
sedan, a rear bumper beam was designed from theoretical calculations and
simulations.
Results
The designed rear
bumper beam and rear floor components equipped with the rear bumper beam were
both fabricated and evaluated by drop-test. In the test of the rear bumper beam
alone, the load input difference to the left and right frames was reduced to 3
kN, while it was 45 kN for the conventional structure. Tests of the floor
component demonstrated that the energy absorption of the non-collision side
frame was enhanced by a factor of 30.
Discussion
In the early
impact phase of the crash, a gap was maintained between the rear bumper beam
ends and the barrier. In the mid-impact phase, only the load on the collision
side frame temporarily increased, but in the late impact phase, the barrier
deformation bottomed out to the rigid board surface and the non-collision side
load increased again, suggesting that the load input has recovered to near
symmetry. The load distribution was similar to that of the full-lap rigid-body impact
and approached the target condition where both the left and right frames could
deform and absorb energy. Further investigations of rear frame deformation
modes and new materials are needed to further enhance overall energy
absorption capability of the vehicle.
Conclusion
The new rear bumper beam was designed
to distribute the load evenly to the left and right frames and to deform both
frames, thereby achieving a higher energy absorption of the entire vehicle
body. This is expected to be applicable to EV and FCV, which require more energy
absorption with increased vehicle weight.
Paper No.23-0081-O
Risk factors affecting
severe thoracic injuries of occupants based on age groups and frontal oblique
collisions
Dooruh Choi, Oh Hyun Kim, Joon Seok Kong, Yeon Il Choo, Kang Hyun
Lee Yonsei University, Republic of Korea
Abstract
Frontal collision is the most common
type of motor vehicle collision occurring in real-world collisions. This study
aims to investigate the risk of thoracic injury depending on age and oblique
direction of collision in a frontal collision. This was a retrospective,
observational study. The study used the Korean In-Depth Accident Study (KIDAS)
database. We selected 1,369 adult occupant patients in frontal collisions and
seated only in the first row. The severely injured occupants were defined as
those who had AIS3+ injury in thoracic regions. The age of occupants was
classified into three groups: <54 years, 55-64 years, and >65 years. The
frontal oblique collision was classified by the PDoF. Considering the PDoF, occupants
were classified into three groups: Far-frontal oblique, Near-frontal oblique,
and longitudinal. The risk of thoracic injury was significant in age, seating
position, and delta-V parameters. 55-64 years occupants OR was 1.819 compared
to <54 years. In addition, >65 years occupants OR were 1.950, a higher
value. The frontal passenger seat had a lower risk of thoracic injury than the
driver seat (OR = 0.465). An increase of 1kph delta-V made a 1.018 OR rise. The
oblique direction was only significant in the occupants with fastened
seatbelts. The OR of the near-frontal oblique direction was 2.964 compared to
the far-frontal oblique direction. The OR of the longitudinal direction was
2.229. Occupants withunfastened seatbelts had no risk
difference in the oblique parameter. The study result showed that elderly
occupants had a higher risk of severe thoracic injury. Furthermore, the oblique
collisions affected to the risk of severe injury only seatbelt fastened
occupants. This study showed the detailed risk of the thoracic region using the
real-world collision database. The research could be used to enhance occupant
safety and advance the crashworthiness of vehicle structures.
Paper No.23-0083-O
A physics-based
fast-running surrogate model for crash-pulse prediction
Peter Wimmer, Oliver Zehbe VIRTUAL VEHICLE Research GmbH, Austria Lars Schories ZF Friedrichshafen AG, Germany
Abstract
Recent developments in safety
performance assessment of safety technologies by virtual simulation show a
trend towards scenario-based approaches, especially for pre-crash technologies
and driving automation systems. The models used for such types of simulations
are rather fast, so many simulations can be performed in reasonable time.
However, if the application of scenario-based approaches is extended to
in-crash occupant protection technologies, finite element (FE) crash models
come into play for e.g., determining the crash pulse. These models are very
time-consuming and not suited for performing large-scale studies. The research
objective therefore was to develop a model that delivers sufficiently accurate
estimations of the crash-pulse in a frontal impact depending on crash
configuration parameters while being fast enough to be used in large-scale
safety performance assessment studies. We built a multi-body-system (MBS) model
consisting of the main frontal crash relevant structural elements (crash boxes,
longitudinal member, cross member, engine, firewall) as well as the rest of the
vehicle (passenger cabin and luggage trunk), which is modelled as one rigid
body. Nonlinear force elements are used to model the elastic and plastic
deformations. We optimized the parameters of the force elements by using
results of 96 FE simulations of a high-fidelity full vehicle model impacting a
rigid barrier. In those 96 simulations, we varied the impact speed, impact
angle and lateral offset. The physics-based surrogate model provides
translational and rotational accelerations, speeds, and positions over time.
The results show a good correlation to the results of the high-fidelity model:
the mean absolute occupant load criterion (OLC) error for all 96 crash
configurations is 0.88 g. The physics-based surrogate model needs less than one
second for one run of 200 milliseconds on 1 CPU while the high-fidelity FE
model needs more than 15 hours on 16 CPUs for the same task. The model can be
used to predict crash-pulses in the range of crash configuration parameters it
was optimized for. It can be extended to other crash configurations. Its parameters
can be adapted to represent other vehicles by adapting physical parameters like
mass, lengths etc. due to the physics-based approach. This is a major advantage
compared to non-physics-based black-box surrogate modelling techniques used for
the same purpose, where the internal parameters do not represent any physical
property. Moreover, the physics-based surrogate model can also be used to
simulate a crash between two vehicles (even with different properties) by using
another model instance instead of a rigid barrier as opponent. The model
delivers an estimation of the crash-pulse, so its main purpose is to be used in
large-scale studies, not to exactly reproduce one singular case. So far it can
only be used in frontal crashes, but it could be extended for rear-end crashes
as well by adding the respective structures at the rear end. The model
developed can predict crash-parameter-dependent crash-pulses and can be an
essential part in accelerating large-scale safety performance assessment
studies of occupant protection systems in frontal crashes.
Paper No.23-0165-O
Heavy truck frontal
impacts and fires
Brian Herbst, Lauren Bell, Christopher Clarke, Jack Bish Safety Analysis & Forensic Engineering, United States
Abstract Industry
and government studies have noted the dangers of heavy truck frontal and
underrun crashes, suggesting various measures to improve safety in these types
of accidents including strengthening front suspension components and adding
protective structures. In 1986, The USDOT found post-crash fires were
involved in 16% of heavy truck fatalities compared to only 4% for cars.
The report identified several mechanisms of fuel tank rupture including frontal
impacts resulting in front axle contact with fuel tanks. The hazards of
exposed side saddle fuel tanks have been known for decades, yet heavy trucks
still use this vulnerable outboard location for fuel tanks. In 1994, the
United Nations ECE published a standard for heavy truck front underrun protective
structures (FUPS); however, the United States still has no requirements
regarding front underrun protection of heavy trucks. A FUPS prevents
underrun and engages the energy absorbing structures of smaller impacting
vehicles, provides protection of the trucks steering components, and helps
prevent the truck's front axle from being displaced into the fuel tank which
can cause rupture and fire. Three real-world crashes are presented wherein
heavy trucks experienced a frontal impact, resulting in fire and serious
injury. In each of these cases, testing was conducted on a production
truck front structural assembly and compared to a similar FUPS equipped
assembly. The effectiveness of FUPS in mitigating damage in these frontal
crashes was assessed.
Paper No.23-0198-O
Frontal head-on
car-to-heavy goods vehicle crashes effect on the restraint system
Martin Östling Autoliv Research, Sweden Linda Eriksson, Mikael Dahlgren
Jason Forman University of Virginia, United Kingdom
Abstract
For car occupants in Europe, a
car-to-HGV (heavy goods vehicle) crash is the third most frequent fatal crash
type after single and car-to-car crashes. Within car-to-HGV fatal crashes,
frontal head-on crashes are most common. These crashes can result in larger
structural deformation of the car or higher velocity changes and accelerations
than single or car-to-car crashes typically do. Structural compatibility and
energy absorbing structures are prerequisites for good crashworthiness, so also
for severe head on car-to-HGV crashes. If the car compartment can be kept
intact there is a potential to improve the current state-of-the-art frontal
restraint systems to provide the occupant with good protection also in
high-severity car-to-HGV crashes. The goal of this study was to identify
potential limitations in a state-of-the-art frontal restraint system in
high-severity car-to-HGV head-on crashes with an intact compartment and propose
improvements to the restraint system to reduce and balance the risk of injury
for all body regions. Finite element simulations were performed using a frontal
sled interior model with a geometry representing a mid‐size sedan. The
frontal sled model was equipped with the semi-rigid seat, a generic seat
consisting of spring-loaded seat and submarining pans, developed to represent
the characteristics of a front seat, and a seat integrated belt system
consisting of a shoulder belt retractor with a 4 kN load limiter and a 2 kN
pretensioner, and a 2 kN lap belt pretensioner. Further, the model was equipped
with a driver airbag, a steering wheel, a collapsible steering column, a knee
bolster, and a foot support. The model was validated by means of mechanical
sled tests using generic 40 and 56 km/h full frontal rigid barrier crash pulses
and THOR-50M v1.9. After validation the performance of the restraint system was
evaluated with the THOR-50M by implementing crash pulses from two car-to-HGV
head-on crashes. For both car-to-HGV crash pulses there were severe
strikethroughs of the restraint system. Improved seat stiffness, increased
shoulder belt load limiter force, and increased knee bolster energy absorption
prevented the strikethroughs and reduced the injury criteria values. However,
the injury criteria values were still higher than current NCAP performance
limits for most of the body regions. To guide the development of adaptive
occupant protection tailored for high severity crashes, injury criteria targets
are required. Such targets should be balanced between feasibility and still
challenging enough to prompt improvements relative to the current state of
risks. Occupant protection in different crash severities is of high priority.
The occupant protection system should be designed to be adaptive to the crash,
i.e. more compliant in low-severity crashes and stiffer in high-severity
crashes. Current occupant restraint systems are most likely capable of the
proposed improvements with existing technologies. However, they are currently
not designed with the level of adaptivity that this study indicates may be
beneficial. More research is needed to develop injury criteria target values
for survival in high severity crashes, as well as sensors thatdistinguish
between low-, mid- and high-severity crashes with the purpose to adapt the
restraint system thereafter.
Paper No.23-0221-O
Driver airbag solution
for next generation steering wheels
Marc Schledorn ZF Friedrichshafen AG, Germany
Abstract
The steering wheel as the central
vehicle motion control device gives today's drivers a high level of trust in
the controllability of their vehicles. Changing vehicle interiors as well as
new occupant positions / postures related to highly automated driving are
impacting the form and function of steering devices. Three technology trends
are influencing future steering wheels: growing electronic content, changing
steering wheel geometries and transformation capabilities and seamless designs.
Over the last decades the appearance of the steering wheel was determined by a
round 360° steering wheel shape, a visible gap between driver airbag &
steering wheel, and driver safety enabled by an airbag deployment centrally
from the front surface. However, future steering wheels are becoming
increasingly seamless with higher integration of HMI functionalities and new
surface appearances like wood optic or glass applications. Such innovative
designs require new driver airbag solutions. This paper examines an alternative
concept capable of revolutionizing the front panel of a steering wheel by
incorporating a driver airbag inside of the steering wheel. The airbag cushion
can deploy from the top side of the wheel through the rim and covers the front
panel, thus helping to protect the driver in case of a crash.
Paper No.23-0300-O
Investigating
slouching in frontal impacts using an HBM in the rear seat
Katarina Bohman,
Emil Gröndahl, Lotta Jakobsson Volvo Cars, Sweden
Abstract
Car occupants may choose a wide range
of sitting postures, including rearward rotation and forward excursion of the
pelvis, through slouching. The overall objective of the study was to contribute
to the understanding of restraint interaction, as a function of pelvis
orientation and lumbar spine posture. Specifically, the aim was to investigate
kinematics of and loading to the occupant in frontal impacts by comparing slouched
and upright sitting postures using state-of-the-art restraints. A human body
model (HBM) of a mid-sized male, the SAFER HBM, was restrained in a simulation
model of the rear seat of a large passenger car and exposed to a full frontal
50 km/h impact. Three different sitting postures, with constant seat backrest
angle were included; a nominal upright sitting posture and two slouched sitting
postures, representing moderate and extreme slouching, respectively. The
position of the seat in front of the occupant was varied to the mid-track
position and the most forward-track position, respectively, to allow for
different knee-interaction. When the front seat was in a mid-track position,
submarining did not occur in any of the slouched postures, while partial
submarining occurred for the extreme slouched posture with the front seat in
the most forward-track position in the model. During the impact, both slouched
postures of the HBM resulted in less torso pitch compared to the nominal
posture. The shoulder belt moved up the sternum to a higher extent in the
slouched postures, leading to less balanced kinematics with the pelvis moving
forward and the upper torso held back by the shoulder belt, contributing to the
less torso pitch. These changes in kinematics for the slouched postures
resulted in higher lumbar spine compression and lower chest loading, relative
to the nominal posture. In summary, slouched sitting postures affect occupant
kinematics and loadings in a frontal impact. By exploring variations in sitting
posture in terms of slouching using a HBM, knowledge can be gained in
understanding the mechanisms of submarining and lumbar spine loading. These
findings are relevant for sitting postures in conventional cars today, in
addition to a wider range of sitting postures as a result of future seat
developments.
Paper No.23-0302-O
Comparison of the
injury risk prediction of the THOR-reclined dummy and the THUMS HBM
Pablo Lozano, Simona Roka, Alessandro Gravina, María De Odriozola, Genís
Mensa
Applus+
IDIADA, Spain William Marshall Cellbond, United Kingdom
Abstract
Autonomous vehicles are expected to
allow car occupants to position themselves in more relaxed positions inside the
vehicle. These new seating positions constitute a new challenge for crash
safety analysis. Therefore, new crash test protocols, adapted to this new
paradigm, may be required in the future. In the literature, most of the virtual
reclined posture analysis has been performed using Human Body Models (HBMs)
which are increasingly used to assess vehicle safety and injury risk, as
currently regulated ATDs (Anthropomorphic Test Devices) are neither designed
nor validated for reclined seating configurations. Nevertheless, these HBM
simulation studies need to be correlated against repeatable physical tests that
allow future cars to be rated according to regulation and consumer testing
protocols. New options for crash dummies such as the THOR-Reclined kit from
CELLBOND; which allows adapting the THOR ATD for these new reclined seating
postures, are being developed and may enable the performance of physical tests
in reclined occupant positions. However, the question of whether its
performance is comparable to that of an HBM remains unanswered. A series of
simulations were then conducted comparing the behavior of the THOR-Reclined
simulation model and the THUMS v4.1 by means of kinematics and injury risk
prediction. Also, a series of tests using the THOR-Reclined in IDIADA's
deceleration facility have been planned and the results will be shared in
future publications. Injury risk prediction was then compared between the HBM
and the ATD. The ATD and the HBM FE models were compared by means of
kinematics, restraint system outputs, injury criteria, and injury risk
prediction. The result of this comparison will be discussed in this paper. Some
differences were observed between the models. THUMS allowed to study injury
risk criteria based on the strain of the rib cage, while the ATD is mainly
designed for measuring displacements and accelerations. The primary limitation
of this work is the lack of thorough validation data of the active HBM and the
ATD model in the studied position. However, this work provides further insight
into the comparability of their performance and the differences found between
the studied models. Differences have been found between the two models, mainly
due to their physical dissimilarities. Nevertheless, some comparisons can be
made between them from a kinematic and injury criteria perspective and will be
shared in this paper.
Paper No.23-0314-O
Update on NHTSA's
OMDB's half barrier analysis
James Saunders,
Dan Parent National Highway Traffic Safety
Administration (NHTSA), United States
Abstract
Research Question/Objective: National
Highway Traffic Safety Administration (NHTSA) has developed an Oblique Offset
Moving Deformable Barrier (OMDB) test procedure. The OMDB test procedure uses
an energy absorbing honeycomb that covers the front face of the OMDB.
Originally, this barrier had a full-width design that was representative of a
typical passenger car. During the development of this test procedure, it was
realized that less than half of the barrier face was being deformed. Since only
half the honeycomb was being deformed it was determined this was a waste of
material and added cost to perform the test. Also, it was brought to NHTSA's attention
that the manufacturing of the full-width barrier face was complicated by the
need for straps. Therefore, NHTSA is developing a barrier with a face whose
width is about half of the original. It is referred to as the “Half Barrier."
Two different versions of the Half Barrier design, V0 and V1, are investigated
herein. Methods and Data Sources: The Full, Half V0, and Half V1 barrier faces
were tested using the OMDB test procedure with rigid moving barrier and
production vehicles, representing different size vehicles. In each test with
production vehicles, THOR-50M Anthropomorphic Test Devices (ATDs) were
positioned in the driver and right front passenger seat. Differences in
barrier, vehicle, and occupant response were assessed using CORA rating software.
To eliminate the variability of production vehicles a set of tests using a
rigid moving barrier was used as the target vehicle. Differences in barrier,
vehicle, and occupant response were assessed using CORA. Results: The impacts
into the rigid moving barrier showed a “Good" CORA score for the rigid moving
barrier responses, though the barrier crush and energy had different trends. In
the production vehicle tests, some differences were seen in the vehicle crash
pulses and intrusions when comparing different barrier faces within the same
vehicle. For example, the large pickup truck showed a more severe crash pulse
using the Half V1 barrier face, suggesting that V1 is stiffer than the other
barrier faces Discussion and Limitations: During this testing it was noted that
the two layers of honeycomb had a slight separation. This separation was seen
in the full-width barrier and both designs of the Half Barrier. It is unknown
how much this separation affects the vehicle and ATD response. This study was
limited by the number of observations, as only one test was conducted for each
barrier face/vehicle combination, and only threeproduction
vehicles were tested. However, the range of vehicles was selected to cover a
wide range of characteristics. Conclusions and Relevance to Session Submitted:
The Half V0 barrier face design has been tentatively selected as a replacement
for the full-width barrier for use in NHTSA's OMDB test procedure. It shows
comparable results to the full-width barrier for both the vehicle and THOR-50M
performance. The Half Barrier V1 design seemed to be too stiff for larger
vehicles.
Paper
No.23-0321-O
Frontal crash
incompatibility of heavy goods vehicle in crash test with passenger car
Rikard
Fredriksson Swedish Transport Administration, Sweden Robert Thomson Chalmers University of Technology, Sweden Krystoffer Mroz, Dion Kruse Autoliv, Sweden Fredrik Törnvall Volvo Technology, Sweden
Abstract
In 1997 the Swedish parliament adopted
Vision Zero which reduced fatalities almost by 2/3 to 1.9 road fatalities
per 100,000 inhabitants for 2020. One guiding principle is maximum speed limits
of 80 km/h without physically separating opposing lanes. Fatal frontal crashes
between passenger cars and Heavy Goods Vehicles (HGVs) are a problem for the
rural road network with speed limits between 50 and 80 km/h. A road network
following the Safe System principles should not lead to fatalities if safe
vehicles, safe infrastructure, and safe road users are present. In the scenario
described above, a rural road posted at 80 km/h without median separation would
need to be operated with safe vehicles, that is, vehicles that are capable of
protecting occupants in frontal crashes. While it may be possible for late
model cars with good safety performance to protect occupants in crashes with
similar cars at relative crash velocities above 120 km/h, the case of a
car-to-HGV impact is less obvious A study of real-world crash data and current
vehicle technology suggested that a frontal crash between an HGV and passenger
car with relative velocity of 100 km/h (50 km/h per vehicle) and 50% overlap
would be a reference to assess infrastructure and vehicle safety levels. The
test was based on vehicles having active systems that reduce original travel
speeds to the proposed test speed before impact. State-of-the-art vehicles (a
Euro NCAP 5 star mid-sized sedan and HGV with energy absorbing Front Underride
Protection Device (FUPD)) were chosen. The test is also comparable with the
Moving Progressive Deformable Barrier test currently used in Euro NCAP. The
test results showed that both vehicles need structural protection system
improvements to provide consistent protection for road users in these types of
high-severity crashes. The car sustained extensive deformations to the outboard
area of the vehicle front resulting in significant deformation to the left
wheel and A-Pillar area. This focused damage was due to the fracture of the FUPD
on the HGV early in the crash event. The FUPD did not engage the energy
absorbing structures
in the car (longitudinal crash beams, which were essentially undamaged. The
50%ile male Hybrid III (HIII) dummy slid off the driver's airbag and struck the
left A-Pillar due to a gap that developed between the side curtain and front
airbag, this was related to the excessive A-Pillar motion. High head
accelerations exceeded the upper limit for recommended Head Injury Criteria
(HIC). Compatibilitybetween HGVs and cars must be improved
for frontal impacts, when less than 50% of the car width engages the
truck structures. The existing FUPD requirements should be reviewed to ensure
that geometric and structural requirements reflect real-world demands in a
crash. Opportunities for improved passenger car restraint systems need vehicle
structure interactions that maintain a stable passenger compartment and
efficiently use energy absorption systems designed into HGVs and passenger
cars. The new EC regulation (2019/1892) for extended fronts is an opportunity
to achieve better car-HGV compatibility by providing more design space in the
HGV front-end.
Paper No.23-0324-O
Fireworthiness of
cabin exhauster vents and the effects of ageing
Chris
Clarke, Brian Herbst, Lauren
Bell Safe, United States Jack Bish Safe laboratories, United States
Abstract In
many case studies, post-collision fires originating outside the occupant
compartment were found to have propagated into the occupant compartment through
the cabin exhauster vents. HVAC systems in modern vehicles include
exhauster vents to flow air out of the occupant compartment, while preventing
air, moisture, and dirt from flowing in. Cabin exhauster vents are
typically constructed with a matrix of elastomeric flaps mounted to a rigid
plastic grate and attached directly to the sheet metal of the vehicle
body. This study evaluates the ability of production and improved
exhauster vent designs to resist fire propagation.
Paper No.23-0327-O
A forensic analysis of
recliner release via connecting rod in rear impact automotive collisions
Jeremy McMillin,
Steve Meyer Safety Analysis & Forensic Engineering, United States
Abstract Occupant
safety in rear impact automotive collisions relies heavily on freestanding
seats to restrain front seated occupants without intruding into the survival
space of occupants in the rear seat [1] [2]. The seatback must absorb
crash energy while remaining sufficiently upright to prevent occupant ramping
and injurious contact with rear seated occupants and / or rear vehicle
structures. Additionally, the front seats must be designed to accommodate
all different occupant statures comfortably [3]. Adjustability is typically
achieved by equipping the seats with a number of features including fore / aft
adjustment, recline adjustment, and often seat height adjustments. These
adjustment features are either manually, or electrically adjustable. A failure
mode in manually adjustable dual recliner seats has been identified wherein the
recliner connecting rod can disengage one, or both, recliners during a rear
impact event, undermining the seat back's ability to restrain the relative
rearward movement of the front occupant. This catastrophic failure mode
presents both front and rear seated occupants with higher risks of severe
injury. Three real world cases are presented wherein manually adjustable
recliners were found to release in a rear impact due to the recliner connecting
rod. Testing and / or demonstration of the failure mode is shown in each case
which shows matching evidence between the accident and test seats.
Paper No.23-0334-O
Potential injury
criteria for collisions with heavy goods vehicles
Jason Forman University of Virginia, United States Martin Ostling, Krystoffer Mroz, Nils
Lubbe Autoliv Research, Sweden
Abstract
Background: Collisions with
heavy-goods vehicles (HGVs) comprise approximately 21% of fatalities in
two-vehicle collisions in the United States, and 14-15% of car occupant
fatalities in Europe. While the immediate need in these collisions lies in
compatibility and structural integrity of the smaller vehicle, once these are
addressed it will be up to the restraint system to manage protection of the
occupants at collision severities that are greater than are commonly evaluated
now. For restraint evaluation in high-severity collisions where survivability
is the focus, different injury criteria targets may be warranted, focused on
balancing injury risk across the body regions to fully utilize the load-bearing
capability across the body. In this study we seek to identify potential injury
criteria target values for predicting injury risk across the body in
evaluations of high-severity collisions. Methods and Data Sources: This study
consisted of a literature review, combined with a field data analysis to
contextualize the distributions of injuries that occur among collisions of
various severity. Data from NASS-CDS (2010-2015) and CISS (2017-2019) were
examined to observe the relative distribution of injury severities by injury
type, focusing on belted occupants in frontal collisions. Injury risk functions
were then reviewed (using simulations) to observe the relative injury risks
predicted across the body in collision severities representative of car-to-HGV
collisions. Results and Discussion: Across collision severities, injury
risks were relatively balanced among the body regions. Most AIS2+ and AIS3+
injury cases occurred in relatively low-severity collisions, due to the very
high exposure to low-severity collisions. AIS4+ injury cases occurred with
similar total counts in low-severity and high-severity collisions, affected by
the balance of exposure and per-crash risk. In high-severity collisions, the
most common injury types were to the ankle, tibia & fibula, brain, thorax,
and lumbar spine, all occurring with similar frequency. In simulations with the
THOR-50M FE model, the injury risk predicted across the body regions exhibits
similar balance to that observed in the field data, except for the risks
predicted in the chest and the hip. Upon examination of the risks observed in
the field data, as well as those observed in the high-severity impact
simulations, injury assessment reference values were developed targeting a 40%
risk, representing a target that is feasible to achieve and which has a high
likelihood of providing a benefit to the field. Conclusions: Injuries occur as
a result of both exposure andper-incident risk. Injury reduction
likely requires safety systems that can adapt to the crash severity, providing
more compliant restraint in low-severity collisions (where the exposure is very
high), and stiffer restraint designed to eliminate strike-through in higher
severity collisions (where the per-crash risk is high). Such adaptive
restraints require injury risk targets designed for the specific collision
severities targeted for evaluation – including more conservative targets for
low-severity evaluations, and higher targets for high-severity evaluations
(focusing on survivability). This study has identified potential means
for defining injury criteria values specifically for evaluations in
high-severity collision scenarios, targeting a balance among the body regions
informed by recent field data.
Tuesday, April 4, 2023, | 08:30-12:30
Chair: Jost Gail, Germany | Co‐Chair: Genya Abe, Japan
TRACK C | Room: G301+G302
Paper No.23-0142-O
The estimated
potential effectiveness of AEB and LKA systems forhead-on crashes
Luke Riexinger,
Joseph-Brandon Gopiao, Hampton Gabler Virginia Tech, United States Rini Sherony Toyota Collaborative Safety Research Center,
United States Takashi Hasegawa Toyota Motor Corporation, Japan
Abstract
Research Objective In 2019, there were
over 3,600 fatal head-on crashes in the US. This represents 10.9% of all fatal
crashes despite accounting for 2.7% of all police-reported crashes. Lane departure
warning (LDW) and lane keeping assist (LKA) systems could help address
cross-centerline crashes. We consider LDW systems to be those that alert
the driver prior to the lane crossing event while LKA systems might perform
automated steering that may help prevent the vehicle from departing the lane.
Automatic emergency braking (AEB) has been effective in preventing or
mitigating front-to-rear crashes by providing significant crash-imminent
braking. The purpose of this study was to estimate the effectiveness of a
simulated LDW or LKA system with a hypothetical AEB system that could activate
in cross-centerline head-on crashes. Methods The National Automotive Sampling
System Crashworthiness Data System (NASS/CDS) is a representative sample of
tow-away passenger vehicle crashes in the U.S. containing in-depth crash data.
Trajectory data was extracted from scaled scene diagrams for 232
cross-centerline NASS/CDS cases with available event data recorder (EDR)
information. There were 111 cross-centerline crashes reconstructed based on the
trajectory and EDR recorded crash pulse. This effort to predict the benefits of
LDW and LKA systems for cross-centerline crashes, involved modeling the crash,
including the road geometry and vehicle dynamics. The encroaching vehicle that
crossed the centerline was simulated with hypothetical LDW and LKA systems and
the impacted vehicle was simulated with and without an AEB system. The outcomes
of the simulations were combined to estimate the potential crash reduction of a
hypothetical LDW and LKA combined with AEB. For simulations that resulted in a
crash, a frontal injury model was used to predict the probability of the
occupants sustaining a moderate to fatal injury (MAIS2+F). Results The
hypothetical LDW system had an estimated crash benefit between 7.5% and 10.8%
and the hypothetical LKA system had a higher estimated benefit of 32%. With the
AEB system in the impacted vehicle, the estimated benefit for LDW increased to
13% to 15%, but the estimated benefit for LKA remained the same. The AEB system
with the LDW system resulted in an estimated 50.8% to 54.3% reduction of
MAIS2+F injured occupants and an estimated 68.4% reduction with the LKA system.
Discussion/Limitations The simulations indicated that AEB has only a small
effect on preventing head-on crashes. However, AEB can mitigate the crash by
rapidly reducing the speed of the impactedvehicle prior to
the collision. While the hypothetical AEB system does not prevent many
additional simulated head-on crashes, it can assist in reducing the likelihood
of passengers sustaining a moderate to fatal injury. Conclusion/Relevance
Previous studies have investigated the benefit of LDW and LKA systems for road
departure and head-on crashes. This is the first study to investigate the
combined benefit of a hypothetical AEB and lane keeping systems for head-on
crashes. This paper is relevant to the session because it evaluates the
estimated safety benefits of these systems using EDR pre-crash and crash data.
Paper No.23-0143-O
Risk assessment and
mitigation of e-scooter crashes with naturalistic driving data
Avinash Prabu, Renran Tian, Stanley
Chien, Lingxi Li, Yaobin Chen Indiana University Purdue
University Indianapolis, United States Rini Sherony Toyota Collaborative Safety
Research Center, United States
Abstract
Recently, e-scooter-involved crashes
have increased significantly but little information is available about the
behaviors of on-road e-scooter riders. Most existing e-scooter crash research
was based on retrospectively descriptive media reports, emergency room patient
records, and crash reports. This paper presents a naturalistic driving study
with a focus on e-scooter and vehicle encounters. The goal is to quantitatively
measure the behaviors of e-scooter riders in different encounters to help
facilitate crash scenario modeling, baseline behavior modeling, and the
potential future development of in-vehicle mitigation algorithms. The data was
collected using an instrumented vehicle and an e-scooter rider wearable system,
respectively. A three-step data analysis process is developed. First,
semi-automatic data labeling extracts e-scooter rider images and non-rider
human images in similar environments to train an e-scooter-rider classifier.
Then, a multi-step scene reconstruction pipeline generates vehicle and
e-scooter trajectories in all encounters. The final step is to model e-scooter
rider behaviors and e-scooter-vehicle encounter scenarios. A total of 500
vehicle to e-scooter interactions are analyzed. The variables pertaining to the
same are also discussed in this paper.
Paper No.23-0146-O
Estimating the
contributions of automatic emergency braking and lane support systems to
achieving vision zero
Morgan Dean, Luke Riexinger Virginia Tech, United States
Abstract
Vision Zero is an approach to
transportation safety that aims to eliminate all traffic-related fatalities and
lifelong injuries. A common strategy to achieving Vision Zero is the safe
system approach, which employs a multitude of transportation-related branches
to create a safe system for all road users. The design and implementation of
advanced driver assist systems (ADAS) is one way to contribute to Vision Zero.
This study used real-world nationally representative crash data from the Crash
Investigation Sampling System to estimate the contributions of two ADAS to
achieving Vision Zero in the United States: an advanced automatic emergency
braking system (A-AEB) and lane support systems (LSS). It was assumed A-AEB has
crash avoidance capabilities for rear-end crashes, left turn across path
opposite direction and lateral direction crashes, and straight crossing path
crashes, as well as injury mitigation capabilities due to prevented crashes as
well as due to delta-v reduction due to system-induced braking. It was assumed
LSS has crash avoidance capabilities for head-on crashes, road departure
crashes, and opposite direction sideswipe crashes. The combined contributions
were estimated to prevent a cumulative 7,054,894 crashes and 869,456 moderate
to fatal injuries by 2050. Despite this, over 125,000 moderate to fatal
injuries are still estimated to occur each year, and the total number of
crashes is not expected to decline. This emphasizes the need for continuous
future contributions from all branches of transportation if the US is to
someday achieve Vision Zero.
Paper No.23-0169-O
Adaptive distance
control – Road safety potentials of an exciting new feature in existing E/E Architecture
Thomas Lich, Thomas Schlender, Daniel Schmidt, Thilo Schock Robert Bosch Corporation,
Germany Matthias Rupp, Thorsten Schori Bosch Engineering, Germany
Abstract
The list of driver assistance features
is getting longer and longer. All this assistance raises the question: Will
driving still be fun in future? Adaptive cruise control (ACC) as SAE Level 1
system adds safety and comfort to the driver. Per definition, ACC takes over
driving tasks and offers limited self-determination in terms of driving
experience and enjoyment. On the other hand, Automatic Emergency Braking (AEB)
systems are designed to prevent a potential collision at latest. Yet, an AEB
system has operational constraints depending on its system capabilities and the
type and complexity of the sensors used. To expand SAE Level 0 safety systems
like AEB, Bosch develops the feature Adaptive Distance Control (ADC). It
transfers an early and comfortable distance control to self-driving situations.
And it adapts to personal driving style to enable a natural driving experience
with a comfortable and noticeable safety benefit. Thus, ADC links between ACC
and AEB to relax traffic flow and to prevent incidents at an early stage. The
present study evaluates the effectivity of ADC in terms of the above-mentioned
safety benefits. It is comprised of a thorough analysis of road traffic
observation data (drone data) and the analysis of rear-end collisions involving
M1-vehicles on German roads. In the first part of the study, real-world traffic
observation data (highD dataset) from six motorways in North Rhine-Westphalia
in Germany was used to determine the time headway (THW) among cars. THW equals
the ACC time gap between two vehicles. In the second part, data from the German
in-depth accident study (GIDAS) was used to identify the number of relevant
crashes which can potentially being positively influenced, i.e., the field of
effect (FoE) for ADC. The analysis of 89,139 passenger car observations reveals
that ADC could support 1 out of 12 drivers to keep a THW ≥ 0.6s if lane
changes are neglected. Furthermore, the FoE for ADC was estimated up to 5.3% of
all crashes with casualties in Germany, depending on its system capabilities.
This corresponds to about 16,100 addressable collisions annually if each car
would be equipped with the ADC feature. The present study reveals that ADC can
prevent crashes. Moreover, the system maintains the balance between safety and
comfortable driving experience and could support a relaxation of the traffic
flow. All this in a standard E/E architecture without adaptations.
Paper No.23-0170-O
Partnership for analytics
in traffic safety (PARTS) cross-industry assessment of real-world adas
effectiveness
Chou-Lin Chen, Chris Wiacek National Highway Traffic Safety
Administration (NHTSA), United States Amy Aukema, Kate Berman, Travis
Gaydos, Ted Sienknecht The MITRE Corporation, United States Tim Czapp Stellantis, United States Schuyler St. Lawrence Toyota Motor North America, United States
Abstract
In 2020, an estimated 2.3 million
people were injured in traffic crashes, and 38,824 people were killed on U.S.
roadways. Advanced driver assistance systems (ADAS) in passenger vehicles hold
the potential to reduce traffic crashes, prevent serious injuries, and save
thousands of lives on our roadways each year. Given the growing rate at which
auto manufacturers are equipping vehicles with ADAS, there is an increasing
need to study and understand the safety benefits and potential limitations of
these technologies. To address this need, the Partnership for Analytics
Research in Traffic Safety (PARTS) was formed in 2018 as an independent,
voluntary data sharing and analysis partnership among eight automobile
manufacturers and the United States Department of Transportation (USDOT). The
not-for-profit MITRE Corporation (MITRE) operates PARTS as the independent
third party and conducted this study at the direction of and in collaboration
with the PARTS partners. The objective of this PARTS study was to explore the real-world
effectiveness of ADAS features in reducing system-relevant crashes,
specifically front-to-rear crashes for forward collision warning (FCW) and
automatic emergency braking (AEB) and single-vehicle road-departure crashes for
lane departure warning (LDW), lane keeping assistance (LKA), and lane centering
assistance (LCA). This study combined 13 states' police-reported crash data
(2016 to 2021) with vehicle equipment data from 47 million vehicles
representing 93 vehicle models (model years 2015 to 2020), resulting in the
study dataset of 2.4 million crash-involved vehicles. This study defined three
crash severities (all, injury, serious) and estimated ADAS effectiveness for
each using quasi-induced exposure and logistic regression, comparing vehicles equipped
with ADAS against vehicles without those features. For the population of all
front-to-rear crashes, the study estimated that crashes were reduced by 49%
(Wald 95% CI: 48 to 50%) when the striking vehicle was equipped with both FCW
and AEB compared against striking vehicles that were not equipped with either.
For FCW alone, the estimated reduction is 16% (13 to 20%). For the population
of front-to-rear crashes involving injury, effectiveness estimates were
slightly higher. The study estimated that front-to-rear crashes were reduced by
53% (51 to 54%) when the striking vehicle was equipped with both FCW and AEB.
For FCW alone, the estimated reduction for crashes with injuries is 19% (13 to
25%). Altogether, this study shows that the combination of warning and active
braking reduced more front-to-rear collisions than warnings alone. The study
demonstrates that AEB performs well even when weather and lighting conditions
are not ideal. This study investigated the effectiveness of Pedestrian AEB with
non-motorists but was unable to detect an effect. For single vehicle road
departure crashes, this study estimated that LDW and LKA reduced crashes by 8%
(5 to 12%). When adding LCA, crashes are reduced by about the same amount (9%,
4 to 14%). This study did not find significant results for vehicles equipped
with LDW alone.
Paper No.23-0192-O
Effects of a bicycle
detection system on police-reported bicycle crashes
Jessica
Cicchino Insurance Institute for Highway Safety,
United States
Abstract
Research Question/Objective Automatic
emergency braking (AEB) is effective at preventing vehicle-to-vehicle rear-end
crashes and pedestrian crashes. Subaru's driver assistance system that includes
AEB, called EyeSight, could detect bicycles in parallel configurations in the
United States in its first and second generations, and added bicyclist
detection in perpendicular configurations in its third generation. The purpose
of this study was to evaluate whether the first and second generations of
EyeSight reduced bicycle crashes in the real world. Methods and Data Sources
The presence or absence of EyeSight was identified through Vehicle
Identification Numbers for model year 2013–2020 Subaru models where the system
was optional. All bicycle crashes and single-vehicle single-bicyclist crashes
with parallel and perpendicular configurations involving these vehicles were
extracted from the police-reported crash databases of 16 U.S. states during
calendar years 2014–2020. The association of EyeSight with bicycle crash
rates per insured vehicle year was examined with negative binomial regression
controlling for calendar year, state, vehicle model year and series, and driver
age group and gender. Quasi-induced exposure analyses using logistic regression
compared involvement in a bicycle crash to the nonsensitive crash types of
being rear-end struck or side-struck, using the same covariates as the negative
binomial regression models. These analyses included crash data from 14 states
where rear-end-struck and side-struck vehicles could be identified. Results
Study vehicles were involved in 856 bicycle crashes, of which 283 had parallel
configurations and 387 had perpendicular configurations. EyeSight was
associated with a statistically significant 29% reduction in parallel crash
rates per insured vehicle year (Rate ratio [RR], 0.71; 95% confidence interval
[CI], 0.53–0.96, p = 0.03), and nonsignificant reductions of 5% in
perpendicular crash rates (RR, 0.95; 95% CI, 0.74–1.21, p = 0.66) and 9% in
overall bicycle crash rates (RR, 0.91; 95% CI, 0.77–1.08, p = 0.28). Effects of
similar magnitudes were seen in the quasi-induced exposure analyses. Discussion
and Limitations An early version of EyeSight reduced bicycle crashes in the
parallel configurations it was designed to detect but did not have much effect
on bicycle crashes overall. Crash configuration was identified by bicyclist and
vehicle direction of travel when they were available. In states where direction
of travel was unavailable, bicyclist precrash actions of cycling along the
roadway with or against traffic and crossing were used as proxies for parallel
and perpendicular configurations, respectively. The actual configurations of
crashes in these states were unknown. Conclusions and Relevance to
Session Submitted Although it is promising that an initial bicyclist detection
system prevented crashes in parallel configurations, a minority of bicycle
crashes are of this type. AEB systems will need to increase functionality and
detect perpendicular crash configurations to meaningfully reduce bicycle
crashes.
Paper No.23-0213-O
Analysis of the
European car road crashes for the identification of the main use cases for a
significant road safety improvement through V2X
Léo CORNEC, Théo
Charbonneau, Pierre Marie
Damon UTAC, France Robby RÖSSLER, Thomas Unger Institute for Traffic Accident Research
(VUFO), Germany Harald FEIFEL Continental Automotive Corporation, Germany Yves PAGE, Thierry Hermitte Renault, France Niklas Puller Volkswagen AG, Germany Mahdi Mousavi ZF Automotive Germany GmbH, Germany
Abstract
Research question in pursuit of Vision
Zero towards traffic-related fatalities and injuries in Europe, the SECUR
project (Safety Enhancement through Connected Users on the Road) was initiated
in a Euro NCAP context. SECUR aims to study the potential of V2X communications
to improve road safety. This paper illustrates the main European crash cases
involving Passenger Cars as ego vehicles and their parameters. The following
opponents were considered: Passenger Cars, Powered Two-Wheelers, Bicyclists and
Pedestrians. Methods and Data Sources An initial study of crashes at a high
level was done to draw a general picture based on German (DESTATIS), French
(BAAC) and European (CARE) crash databases. Then, an in-depth study was
performed to select and define the SECUR crash cases and their characteristics.
As part of this in-depth analysis a generic scenario catalog was developed,
covering traffic crash situations, that the driver of a passenger might
encounter. The most relevant scenarios regarding accidentology were determined
providing the baseline to develop a test environment for a useful V2X-system.
Based on the German Insurance Association crashes classification (GDV) and the
German in-depth crash database (GIDAS), this catalog clusters all the GDV crash
types in 28 categories, each crash being analysed from the perspectives of both
participants and considering all different opponent types. The data of the most
relevant 15 crash scenarios were provided through a GIDAS-based in-depth study,
considering a set of 16 parameters. Results According to the in-depth crash
analysis, 15 out of 112 crash scenarios were identified as the most relevant
ones regarding the number of Killed and Severely Injured (KSI) and the
relevance of V2X. These 15 scenarios consider the 4 types of road users and
cover 71% of all the KSI crashes from the catalog. Among them Straight Crossing
Paths, Left Turn Across Path and Rear-End crash situations. The parameters
study has shown that the most significant crash blackspot is at intersections
with structural view obstruction. Discussion and Limitations This study is
subject to certain limitations. First, it is expected to be European
representative, so the study was based on GIDAS and complemented with analyses
of CARE and the in-depth database (IGLAD). However, the European
representativity is still limited by the GIDAS-weighting upon CARE. Moreover,
it is complex to draw conclusions for new vehicles as the current databases
naturally include old information and are representative of a past context
(vehicle without state-of-the-art safety systems). Therefore, in order to have
a dataset more representative of the current context, crashes involving a
vehicle without ESC were filtered out. Conclusion The main crash cases to be
ruled out for a significant road safety improvement through V2X are illustrated
in this paper. The results have shown that significant white spots that are not
addressed by ADAS due to physical sensor limitations (e.g., obstruction)
remain. And it is precisely where V2X benefits sit, standalone or fused with
current systems. SECUR results will feed Euro NCAP V2X introduction into the
protocols and also further NCAP developments in other regions.
Paper No.23-0245-O
ADAS in your pocket –
a review of the features, functions and future of smartphone-based advanced
driver assistance systems
David Paine, Kylie Webber, Michael Paine Vehicle Design and Research, Australia
Abstract
Advanced Driver Assistance Systems
(ADAS) are technology systems that rely on a combination of sensors that scan
the road environment to detect potentially hazardous situations and assist the
driver to either avoid the hazard, or to reduce the severity of outcomes if a
crash is unavoidable. Recent developments in consumer-level smartphone
technology have allowed third party software applications to make ADAS
functionality accessible to millions of mobile phone users. By utilising the
smartphone's hardware such as cameras, positioning sensors and processors,
together with software-based object recognition and tracking algorithms, these
applications purport to allow users to receive real time road hazard detection
and warnings. These smartphone-based ADAS applications are compatible with many
popular models of smartphone and offer ADAS functionality that includes Forward
Collision Warning (FCW), Lane Departure Warning (LDW) and Intelligent Speed
Assist (ISA). ADAS related applications are identified and reviewed for
claimed features and functionality. Applications with the most promising
functionality are acquired for more detailed evaluations. We review the
features and functionality of selected ADAS applications using several
different smartphone models. We report on the results of on-road performance
evaluations that examine the effectiveness and limitations of these. We also
explore potential road safety benefits for drivers whose vehicle is not
equipped with ADAS, but who have a smartphone available when they drive. The
results confirm that ADAS applications are capable of vehicle
detection/tracking, lane marking detection, road sign detection, speed zone
detection and related warning functionality, however the performance between
apps varied and issues such as false alerts, non-detections and incorrect
detections were recorded. While smartphone-based ADAS can provide reliable, and
potentially useful road safety benefits to drivers, these potential benefits
depend on a combination of the hardware capability of the smartphone, the
sophistication of the application and, to a lesser extent, the correct set up
of the smartphone in the vehicle. Furthermore, while smartphone-based ADAS has
the potential to improve road safety, especially where OEM-fitted ADAS is not a
feasible option, there are inherent limitations posed by current technology.
Finally, subject to appropriate provisions in relevant regulations, the
barriers to the adoption of smartphone-based ADAS appear low and the main
barrier to adoption is that smartphone users are unaware that ADAS applications
exist. We foresee that continued developments in smartphone hardware and
processing capability, together with software evolution in ADAS applications,
will continue to improve the reliability and effectiveness of smartphone-based
ADAS in the future.
Paper No.23-0269-O
Active safety of
self-propelled trailers: Proposal for safety requirements
Patrick
Seiniger, Oliver Bartels, Maxim Bierbach German Federal Highway Research Instutute
(BASt), Germany
Abstract
Trailers are by definition
non-propelled, towed vehicles. They pose resistance forces to the towing
vehicle, resulting from e.g., rolling resistance, friction, air resistance. New
concepts are proposed where trailers would be able to support the towing
vehicle by reduction of the toeball forces, sometimes even pushing the towing
vehicle. This would allow for higher traction of the vehicle combination,
possibly even a higher overall energy efficiency when the required energy
storage system would be distributed to both vehicles. A study conducted by BASt
did investigate the possible influence of driven trailers on the driving
dynamic properties of the vehicle combinations. Driving experiments with two
prototype trailers (caravans) had been carried out in direct comparisons with
active and inactive trailer motors. The experiments focused on possible effects
on the handling (double lane change test) and lateral stability (yaw damping
test). Additionally, calculations had been carried out to investigate the
transferability of the results. Based on the available data, it was shown that
there is no negative impact of the propelled trailer to the stability of the
towing vehicle and vehicle combination, provided that there is always a
remaining towing force in the towball, and no torque vectoring between the
trailer wheels. It was also found that handling benefits from a driven trailer.
Theoretical calculations show that when these two conditions are met (=no
torque vectoring, no pushing), propelled trailers are safe with regards to
driving dynamics. Theoretical calculations also show that torque vectoring has
a potential to even further improve handling and stability, however possible
faults of the drive system and control strategy could negatively influence handling
and stability. The study had been carried out with only two prototype vehicles.
Calculations checked that the results can be transferred to almost all kinds of
trailers. Articulated trailers that have a steering of their own, however, need
to be excluded from the conclusions without further research. Trailers for
single-track vehicles (motorcycles, bicycles) are still under investigation. As
a conclusion, it has been identified that propelled trailers where a towing
force in the coupling remains (=the trailers compensate their driving
resistance only partially, they do not push the towing vehicle) and without
torque vectoring do not have negative effects on the stability of the
combination and can have possible effects on the handling. This is true for
non-articulated trailers, including semi-trailers and central-axle trailers.
Regulations could as a next step be adapted, so that the positive effects
towards traction and energy efficiency could be demonstrated. Also, as a next
step, the benefits and possible issues with torque vectoring should be
identified.
Paper No.23-0082-O
Reducing fatalities in
road crashes in Japan, Germany, and USA with V2X-Enhanced-ADAS
Harald Feifel Continental Autonomous Mobility, Germany Bettina Erdem, Marc Menzel Continental Automotive Technologies, Germany Robert Gee Continental Automotive Systems, United States
Abstract
Objective While Advanced Driver
Assistance Systems (ADAS) improve safety, on-board sensors such as cameras,
radar and lidar have limitations in preventing crashes: a) early recognition of
non-line-of-sight (NLOS) vehicles and vulnerable road users (VRU: pedestrians,
bicyclists, and motorcyclists) and b) early recognition of the intention of
other road users. V2X technology can overcome this challenge. Basic V2X use
direct short-range communication between vehicles and provides only a gradual
solution toward improving ADAS. First, the slow introduction rate of V2X
results in a low likelihood of both vehicles being equipped with V2X and
therefore in preventing a crash. Second, there are impediments to VRU
participation in V2X communication, resulting in a lack of VRU protection in
NLOS scenarios. Collective Perception V2X using sensor data sharing can help to
protect vehicles without V2X technology. Collective Perception V2X can also
help to protect VRU by sharing information on road users that is collected by
sensors in other vehicles or on intelligent infrastructure. The first objective
of this paper is to quantify how Basic V2X can address fatal crashes in
conjunction with ADAS by improving situational awareness in non-line-of-sight
scenarios, and by providing information on the intention of traffic
participants in critical situations. The second objective of this paper is to
quantify how Collective Perception V2X can further boost the effective
equipment rate in vehicles and protect VRU that are not otherwise protected by
Basic V2X and ADAS. Method Using crash statistics from Japan, Germany, and the
US, we analyzed the share of fatal crashes between vehicles and VRU. Crash
scenarios due to limitations of on-board sensors were identified to quantify
the target population for V2X. Starting with the V2X introduction rates
presumed by the US DOT NPRM, we modeled the effective V2X communication rates
for vehicles and VRU over time, assuming that all vehicles were equipped with
ADAS. We analyzed the benefit of Basic V2X, in addition to conventional ADAS,
in addressing vehicle-vs-vehicle and vehicle-vs-VRU crashes. We investigated
whether Collective Perception V2X could increase the effective communication
rate between vehicles. Additionally, we examined how Collective Perception V2X
could help to detect VRU that are insufficiently addressed in NLOS
circumstances. The analysis included intersections with potential intelligent
infrastructure and roadways without infrastructure. Results The following three
fields-of-action of Basic V2X and Collective Perception V2X were identified,
and the potential in addressing vehicle-vs-vehicle and vehicle-vs-VRU crashes,
were quantified: - Basic V2X raises the awareness of other equipped vehicles, -
Collective Perception V2X boosts the effective vehicle equipment rate, -
Collective Perception V2X protects VRU that are otherwise unprotected. Outlook
The results indicate that the combination of Basic V2X, Collective Perception
V2X, and ADAS can be highly beneficial for road safety. It is therefore
important to ensure sufficient and protected frequency spectrum in the 5.9 GHz
band for basic and advanced V2X messages like BSM/CAM and SDSM/CPM. Subsequent
research should focus on analyzing the potential of V2X for automatic emergency
braking, including safety level considerations when utilizing over-the-air V2X
data.
Paper No.23-0103-O
Automatic emergency braking
– How can we set the bar to maximize safety?
Benoit Anctil, Dominique Charlebois, Shivang Dube, Peter Burns
Transport
Canada, Canada Annie Saleh, Guillaume Pierre, Victor
Chirila, Fleury Nahimana PMG Technologies Inc., Canada Abstract
It is estimated that Automatic
Emergency Braking (AEB) systems could potentially help mitigate 80% of rear end
and pedestrian/cyclist crashes assuming they can stop the vehicle under all
circumstances. In practice, however, technical limitations of systems (sensors,
control unit, and actuators), vehicle dynamics, and environmental conditions
(e.g., lighting, road conditions) reduce the overall crash avoidance
performance of AEB systems. In an effort to better understand these
limitations, Transport Canada initiated a study aiming at establishing the
general AEB performance of the Canadian vehicle fleet. Three collision
scenarios from recognized test protocols were considered: 1) stopped lead
vehicle, 2) slower moving lead vehicle, and 3) crossing pedestrian. A total of
43 light duty vehicles (passenger cars, SUVs, and pickup trucks) from 26
different manufacturers were tested for car-to-car scenarios, and 30 vehicles
were tested for car-to-pedestrian scenarios. Vehicles' model years ranged from
2013 to 2022. The large sample size of this study covers a significant
proportion of the most popular vehicles sold in Canada. To ensure test
repeatability, vehicles were equipped with precision positioning systems, audio
alert detectors and driving robots. The optimal AEB operating speed range
needed to address most real-world collisions was determined from recent crash
data. Overall, the performance of vehicles tested was found to improve over the
years when compared to the thresholds defined in the U.S. DOT/NHTSA
Commitments, but a large proportion struggled to meet the requirements defined
in UN regulation No. 152. Interestingly, the results obtained with the best
performing systems suggest that it is now possible to achieve even better speed
reduction outcomes than the criteria defined in the selected references The
results of this study demonstrate that, with the continuous improvements of AEB
systems, it is now possible to exceed performance levels defined in existing
requirements. Technological advancements and added capabilities, including
pedestrian detection, continue to increase the crash avoidance potential of
these systems and, thus, enhance road safety. The methods and criteria
evaluated in this study can help to inform future international policy and
regulatory requirements.
PEER REVIEW Paper No.23-0114-O
Effects on crash risk
of automatic emergency braking systems for pedestrians and bicyclists
Anders Kullgren Folksam Insurance Company, Sweden Khabat Amin Swedish Transport Authority, Sweden Claes Tingvall AFRY, Sweden
Research
The first
Automatic Emergency Braking (AEB) systems were introduced in 2008 aimed to
reduce rear-end crashes. Since then, several AEB systems aimed to reduce other
collision types have been introduced. Studies have been showing that they are
effective in reducing crashes. The aim with this study is to show crash
reductions of cars fitted with AEB systems with detection of pedestrians and
those with detection of bicyclists.
Methods
The Swedish
Traffic Accident Data Acquisition (STRADA) was used that includes road traffic
accidents reported by the police and by emergency hospitals. Crashes occurring
between 2015 and 2020 and with cars of model years 2015 to 2020 were included.
The statistical analysis used odds ratio calculations with an
induced‐exposure approach where the outcomes of sensitive and
non-sensitive crashes were studied. The sensitive crashes were hit pedestrians
and bicyclists respectively. The non‐sensitive crash type usedwere in both
comparisons struck vehicles in rear‐end crashes. Evaluations were also
made for different light conditions, weather conditions and speed limits.
Results
A total of 903
hit pedestrians and 1475 hit bicyclists were included. The non-sensitive
crashes consisted of 1978 vehicles struck in the rear. The overall effect on
crash risk for AEB with pedestrian detection was a reduction of 13% (+/- 15%)
and for AEB with bicyclist detection 17% (+/- 17%). None of these reductions
were statistically significant. When separating for light conditions no
reduction in crash risk either for AEB with pedestrian detection nor for AEB
with bicyclist detection could be seen in darkness. However, in daylight and
twilight conditions AEB with detection of pedestrians was found to reduce
pedestrian crash risk with 18% (+/- 17%) and AEB with detection of bicyclists
was found to reduce the bicyclist crash risk with 20% (+/-18%). With the data
material available no significant findings could be seen when separating for
weather conditions and speed limits.
Discussion
It is positive to
see that AEB systems with detection of pedestrians and bicyclists both show a
crash reduction. The findings regarding the performance regarding AEB for
pedestrians in various light conditions were in line with another recent study.
The studies clearly show that it is important that detection in darkness is
improved. This is especially important regarding pedestrians as studies show
that they to a large extent are struck in darkness. The reductions in number of
crashes found were the overall reduction at for example all speed limits, road
types and weather conditions. The Swedish car fleet has a larger proportion of
Volvo models than other countries, which should be considered in comparisons
with studies from other countries.
Conclusion
AEB systems with detection of pedestrians
and bicyclists were found to reduce the numbers of hit pedestrians and
bicyclists, but only in daylight and twilight conditions. In darkness no
reduction for either hit pedestrians nor bicyclists were found. To the authors
knowledge this is the first study that evaluates crash reduction for AEB with
detection of bicyclists.
Paper No.23-0306-O
ADAS Reliability
against weather conditions: quantification of performance robustness
Taufiq Rahman, Andrew Liu, Daniel Cheema National Research Council
Canada, Canada Victor Chirila PMG Technologies Inc.,
Canada Dominique Charlebois Transport Canada, Canada
Abstract
Advanced Driving Assistance System
(ADAS) technologies provide an additional safety layer besides human drivers.
Continual evaluation of the safety of the dynamic driving task enables ADAS to
initiate a corrective (e.g., automated braking) and/or a preventative (e.g.,
audio-visual alerts) action if and when an unsafe roadway event is detected. To
provide situational awareness, these safety systems principally rely on the
vehicle mounted sensors whose performance can be greatly affected by weather
events such as strong sunlight, atmospheric precipitation (rain, snowfall,
fog), etc. Correspondingly, this study was conducted to characterize the
performance of ADAS features in different weather conditions. Automated
emergency braking (AEB) was selected as a representative ADAS feature. Two
vehicles under test (VUT) were equipped with perception sensors such as LiDAR,
RGB camera, infrared camera, radar, inertial measurement unit, GNSS, etc.
Relevance and prominent use of these sensors in pre-production and developmental
driving automation systems are widely reported in the literature. In addition,
the data available through the OBD-II port of the VUTs was also recorded with
temporal correspondence with the external sensors. Although weather related
tests involving automotive systems have been traditionally performed in weather
chambers, adoption of these test protocols for ADAS testing can be challenging.
Because testing of ADAS must be performed dynamically, a runway of several
hundred meters is necessary, and typical weather chambers cannot accommodate
this requirement. Alternatively, this study utilized naturally occurring
weather events to record AEB performance. For the purpose of this study, AEB
tests performed under optimal weather conditions (sunny and bright) constituted
the baseline performance. The same tests were performed in a number of
different weather and roadway conditions, e.g., day/night, snow covered
asphalt, persistent snowfall, overcast, rainfall etc. A number of metrics
resulting from the test data analysis were used to quantify AEB performance in
adverse weather conditions. These include distance of the test target when AEB
system detected an imminent collision in different weather conditions, distance
of the test target when AEB initiated an automated braking action in different
road surface conditions (dry/wet asphalt vs snow covered asphalt), and whether
AEB was successful in stopping a collision from happening in the test
scenarios. These metrics helped to identify the failure modes of AEB in adverse
weather conditions. It should be noted that quantification of ADAS performance
robustness against adverse weather conditions is closely related to
quantification of operational design domain (ODD), which is an emerging topic
in driving automation systems literature. Nonetheless, observations and
inferences made from this study will be used to design more comprehensive and
elaborate test protocols for ADAS that are expected to improve in system
capacity and ODD in near future.
PEER REVIEW Paper No.23-0104-O
The ideal vulnerable
road user – A study of parameters affecting VRU detection
Dominique
Charlebois, Benoit Anctil, Shivang
Dube Transport Canada, Canada Annie Saleh, Guillaume Pierre, Victor
Chirila, Marilyn Paquette PMG Technologies Inc., Canada
Research
In 2020,
Vulnerable Road Users (VRUs) accounted for 17.5% of total Canadian road
fatalities and 18.4% of injuries according to Transport Canada's National
Collision Database. Advanced Driving Assistance System (ADAS) technology has
the potential to reduce the risk to VRUs the research objective was to
determine through track testing activities, which parameters influenced the
detection of pedestrians and cyclists.
Methods
Since 2015,
Transport Canada and PMG Technologies have been conducting research on ADAS
with a focus on Automatic Emergency Braking systems (AEB) and VRU. The track
testing methods used followed the Euro NCAP AEB VRU test protocols, and
derivatives thereof. The standardized articulated adult male pedestrian (EPTa),
eight-year-old articulated child pedestrian (EPTc) and adult bicyclist (EBT)
targets were used as the control group. An iterative test approach was used to
benchmark the detection capabilities of systems with variations in target
configuration and environmental conditions against these control group. Over
1,400 track tests using 38 scenarios have been conducted using 13 vehicles
(model year 2019-2021). The environmental conditions included nighttime, snowfall,
and snow-covered roads. Pedestrians were dressed in winter clothing and
accessories including, hat, jackets of different colours, backpack, and
umbrella. Adult and child pedestrian targets were joined to generate
obstructions and alter their silhouette with the intent of challenging vehicles
with realistic urban-like scenarios. The scenarios were selected and designed
to reflect real world situations where drivers could benefit from ADAS
assistance. All variation from the test protocols was documented with the
purpose of recording influential parameters. The vehicles were equipped with
positioning systems, audio, and visual alert detectors, and driving robots. The
data collected was used to compare the timing of forward collision warnings
emitted by the systems between different test configurations relative to the
baseline condition.
Results
This study
illustrates how iteration outside the control condition can affect the
vehicles' performance. More challenging weather conditions and urban like
scenarios on the test track challenged some vehicles more than others as
compared to the control condition.
Discussion
ADAS equipped
vehicles are increasingly exposed to less-than-ideal road conditions and a wide
range of pedestrian profiles. Understanding system limitations in a controlled
environment enables to evaluate their potential in the real world, how they
perform and what parameters affect their responses. Limitations of this study
include the small sample size of the vehicles used as compared to the Canadian
fleet and the selected number of VRU scenarios possible on the test track to
represent real world conditions.
Conclusion
Vehicles tested have various levels of
performance and capabilities when mitigating risk to VRU. This paper
presents opportunities to quantify potential safety benefits when vehicles are
operated in a more challenging environment. The results also serve as an
indicator of robustness of this type of system for all situations. This
paper describes a study highlighting the importance of VRU avoidance
technologies in making the roads safer.
Tuesday, April 4, 2023, | 2:00‐6:00
Chair: Matthew Craig, United States | Co‐Chair: André Eggers, Germany
TRACK A | Room: G303
Paper No.23-0030-O
Development of a human
body model (THUMS Version 7) to simulate kinematics and injuries of reclined
occupants in frontal collisions
Takao Matsuda, Naoya Kobayashi, Noriyuki Fujita, Yuichi Kitagawa Toyota Motor Corporation, Japan
Abstract
This paper describes the development
of THUMS Version 7 which is a virtual human body model (HBM) to be used for
simulating impact kinematics and injuries of occupants assuming a reclined
seating posture in vehicle frontal collisions. In highly automated vehicles, it
is expected that occupants wish to take various sitting positions including a
reclined posture. Prior research has found that there is a relatively high
possibility of injury to the occupant for a reclined posture in vehicle
collisions. If the lap belt engagement with the pelvis is lost in a frontal
collision, there is the possibility that the internal organs are highly loaded.
The latest released Version 6 does not have precise representation of the small
intestine but has a generic soft solid. It was decided to upgrade THUMS for
accurate prediction of internal organ injury. The geometry and mechanical
properties of the small intestine and the other relevant body parts were
fundamentally revised in Version 7. The interaction between the pelvis and lap
belt was most important in simulating occupant kinematics leading to the
abdominal loading. The pelvis dimensions and soft tissue thickness of the
anterior pelvis were carefully reviewed to represent the belt-pelvis
interaction in the average body-size occupant. Three anthropometry models were
generated: 5th-percentile adult female (AF05), 50th-percentile adult male
(AM50), and 95th-percentile adult male (AM95). The geometry and material
properties of the abdominal soft tissue, small intestine and mesentery were
carefully defined to realistically reproduce the mechanical responses during
the abdominal loading by referring to the loading test data on actual human
tissues reported in the literature. The lumbar spine was also revised. Prior
research has found that the lumbar spine receives a high load when the pelvis
is firmly restrained to prevent disengagement of the lap belt in a reclined
posture. The material properties of the intervertebral discs and spinal
ligaments were carefully reviewed. The validity of the updated models was
examined by comparing the mechanical responses with the test data from Post
Mortem Human Subjects (PMHS). It was confirmed that the Version 7 responses
generally matched the test data or fell within the test data variability. The
validations were performed at both component and whole-body level by referring
to the available test data.
Paper No.23-0050-O
Determination of best practices
for human body model gravity settling
Brian von
Kleeck, Juliette Caffrey, Ashley Weaver, Francis
Gayzik Wake Forest University School of Medicine,
United States Jason Hallman Toyota Collaborative Safety Research Center,
United States
Abstract
The simulated action of coupling a
computational human body model to a vehicle seat, commonly referred to as model
settling, is an essential, initial aspect of any crash simulation. There is a
gap in knowledge related to the necessary duration of this activity to
sufficiently couple the human model to the seat. In this study, THUMS v4.1 was
gravity-settled in two postures, an upright driver, and a reclined occupant,
into a seat model. Simulations were performed using three seat foam
stiffnesses, three friction coefficients and both with and without a constraint
on the motion of the pelvis for a total of 18 simulations per posture. Each
simulation was run for 800 ms, a time determined to be sufficiently long to
identify a settled end state. In separate simulations, a 0.5g magnitude, 200 ms
half sine wave pulse was applied to the seat in the backwards direction to
measure coupling between the human body model (HBM) to the seat. Model quality
metrics were measured at the first four kinetic energy local maximums and local
minimums to compare physically consistent time points between simulations.
Kinetic energy, contact penetrations, change in HBM element quality, seated
contact area and seat pressure were measured and compared to this settled end
state. A pass/fail range was assigned to each metric. A pass was assigned if
the value fell within ±1 standard deviation of the average simulated end state
value at 800 ms (contact area, seat pressure) or between the simulated end
state value and the baseline THUMS value (contact penetrations, model quality,
perturbation test). A passing time point for a simulation received a score of
1, a failing time point for a simulation received a score of 0. Scores for all
simulations were added and normalized for each local maximum and local minimum,
and the first time point to receive a score greater than 3 (out of 5) and pass
the perturbation test was determined to be sufficiently settled. The third
kinetic energy local minimum was selected for the upright driver posture and
third local maximum for the reclined occupant. Both have average gravity
settling times of approximately 405 ms. The pelvis constraint appeared to
contribute to a more rapid arrival at the long term settled state for the
upright seated posture. Constraining the pelvis is not recommended for the
reclined posture. The results suggested that for best practice a settling time
of at least 400 ms is required to sufficiently couple the model to the seat in
either posture.
Paper No.23-0094-O
Investigation on effective
approaches of brain FE modeling to improve its validation performance on brain
deformation during head impact
Noritoshi Atsumi, Yuko Nakahira, Masami Iwamoto Toyota Central R&D
Labs., Inc., Japan
Abstract
The finite element (FE) model of the
human brain is an effective tool for predicting brain strain during head
impacts that can result in traumatic brain injury (TBI). Although many
brain FE models have been proposed and updated upon thus far, it was unclear what
kind of modeling approaches would critically contribute to improving the
biofidelity of the models. This study investigated whether the
implementation of material anisotropy of the brain tissue or the appropriate
representation of the boundary conditions around the ventricle would affect the
validation performance of modeling brain deformation during head
impact. Axonal fiber tracts of the whole brain were extracted from
diffusion-weighted images in the Amsterdam Open MRI Collection using
tractography. The direction of the material axis in each element of the
white matter of the previously developed human brain FE model was determined
based on axonal fiber tracts. Incompressible fluid dynamics (ICFD),
including perfusion pressure, was also applied to the intraventricular
cerebrospinal fluid (CSF) of the model. Validation of the displacement and
strain in the brain during head impact was performed based on cadaveric test
data, wherein quantitative evaluation of validation accuracy was conducted
using the CORrelation and Analysis (CORA) method. The CORA scores of the
model were compared with those of the model with isotropic material or those of
the model without ICFD. The difference in CORA scores for brain
displacement was minimal among the models. On the other hand, the CORA
scores for brain strain of the model with ICFD were higher than those without
ICFD. However, CORA scores for the brain strain of the anisotropic model
based on the axonal fiber tracts were similar to or lower than those of the
isotopic model. Comparing CORA scores among the models indicated that
introducing ICFD to the intraventricular CSF improved the validation
performance of the brain FE model. However, implementing anisotropy of the
white matter based on tractography at the element level does not necessarily
improve the validation performance of the brain FE model. In addition,
evaluating the validation accuracy of the brain FE model using brain
displacement did not reflect the difference in the accuracy of predicting brain
strain during head impact. A limitation of this study includes the spatial
registration of axonal fiber tracts with the FE model using affine
transformation. It would be more desirable to consistently conduct FE
modeling and tract extraction so that the differences in brain geometry and
axonal fiber pathways for each subject could be considered. The findings
in this study indicate that the appropriate representation of the boundary
condition around the ventricle using ICFD would affect the validation
performance on the brain strain in the brain FE model rather than the accuracy
of the description of the anisotropy at the element level. These findings
may provide useful insights into modeling strategies of the human brain to
predict TBI due to head impact associated with traffic accidents.
PEER REVIEW Paper No.23-0118-O
Response of small
female and average male model with active musculature in pre-crash braking and
low-speed impacts in frontal-oblique direction
Karan Devane, Hana Chan, Devon Albert, Andrew Kemper, F. Scott
Gayzik Virginia Tech-Wake Forest University Center
for Injury Biomechanics, United States
Research
The need for
human body models capable of predicting occupant kinematics in pre-crash and
low-speed scenarios has led to the development of active models. It is equally
important to validate these active models using volunteer data. The objective
of this study was to validate computationally efficient small female (54.1kg,
149.9cm) and average male (78.4kg, 174.9cm) models with active muscles using
volunteer data in a frontal-oblique loading direction.
Methods
The Global Human
Body Models Consortium small female (F05-OS+Active) and average male
(M50-OS+Active) simplified occupant models with active musculature were used in
this study. Both models have been previously validated in the frontal loading
direction. The models use a PID controller-based muscle activation strategy,
which uses joint angles and muscle lengths as control variables. Occupant
responses of six 5th percentile female and six 50th percentile male volunteers
(n=12 total) were recorded in two muscle conditions (relaxed and braced) at two
acceleration pulses representing pre-crash braking (1.0g) and a low-speed
impact (2.5g). All experiments were performed in a rigid buck with a principal
direction of force of 330°. Kinematics were measured using a VICON motion
capture system. Multi-axis load cells were used to measure reaction loads at
each test buck interface. A total of 48 experimental tests were performed. The
data from these experiments were used to simulate a total of 16 simulations in
a full factorial series with; two acceleration pulses (1.0g and 2.5g), two
models (F05-OS+Active and M50-OS+Active), two muscle states (activation and
control, i.e., no activation), and two muscle conditions (relaxed and braced).
Each model's kinematics and reaction forces were compared with experimental
data. A CORA analysis was carried out using reaction load time-history data.
The difference between the active and control model was checked for statistical
significance by performing Wilcoxon signed-rank tests using peak forward and
lateral excursion data.
Results
The occupant peak
forward and lateral excursion results of both active models reasonably matched
the volunteer data in the low-speed sled test simulations for both pulse
severities. The differences between control and active models were
statistically significant in 7 out of 8 cases. The CORA scores calculated using
reaction loads were higher for active models than control (average CORA scores:
M50-OS+Active= 0.568, male control= 0.491, F05-OS+Active= 0.612, female
control= 0.481).
Discussion
There are a
limited number of studies that have focused on validating 5th female active
human body models due to the limited availability of 5th female-specific
experimental data. This study bridged that gap by validating the F05-OS+Active
model using experimental data and at the same time comparing its results with
the average male model, which was the focus of many prior studies. One
limitation of this study was the lower CORA scores for the active model.
However, this can be resolved in follow-up studies by adjusting PID controller
parameters for acceleration severity and muscle condition.
Conclusion
The response of the F05-OS+Active and
M50-OS+Active models were in good agreement with the volunteer data. The
results highlight their ability to predict occupant kinematics in pre-crash
maneuvers and low-speed impacts in the frontal-oblique direction.
Paper No.23-0123-O
Field assessment of
GM/OnStar occupant-based injury severity prediction models
Susan Owen General Motors (GM), United States Stewart Wang, Peng Zhang University of Michigan, United States
Abstract
Injury Severity Prediction (ISP)
models provide emergency responders with a rapid assessment of potential
serious injury for occupants in vehicle accidents around the globe. ISP
models predict the need for high level trauma care so that appropriate
Emergency Medical Services (EMS) can be dispatched as quickly as possible to
improve patient outcomes. In 2020, OnStar implemented its first occupant-based
ISP models which predict outcomes for specific seating locations.[1] Models
were developed and validated with NHTSA NASS CDS [2] and CISS [3] data. This paper
seeks to assess model performance in the field using vehicle-based crash data
and real-world occupant outcomes. This study leverages data from a sample of
over 1,500 Michigan Advanced Automatic Crash Notification (AACN) events
involving over 1,700 front row occupants to assess model performance.
Vehicles include model years 2013 to 2020 and span several segments, including
passenger cars, SUVs, and light trucks. AACN telemetry data and
ISP-predicted outcomes are compared to actual Injury Severity Scores (ISS) for
transported occupants. For non-transport cases, police reported injury
severities (KABCO scores) are also examined. Measures of sensitivity,
specificity, and likelihood ratio are calculated. False negative cases are used
to understand model limitations. A range of threshold values used to
assess “high" injury risk are also explored to highlight potential tradeoffs.
Statistical analyses show that front row occupant models predict ISS 15+
injuries with high levels of accuracy. Metrics compare occupant-based model
performance to prior vehicle-based ISP formulations. This study demonstrates
that models based on government-sampled data sets are producing reliable
results in the field.
PEER REVIEW Paper No.23-0129-O
Thoracic and pelvic
responses and injuries to Post-Mortem Human Subjects (PMHS) in rear-facing seat
configurations in high-speed frontal impacts
Yun-Seok Kang, Alexander Bendig, Amanda Agnew, John Bolte The Ohio State University, United States Jason Stammen, Kevin Moorhouse National Highway Traffic Safety
Administration (NHTSA), United States
Alena Hagedorn Transportation Research Center Inc, United States
Research
One potential
non-standard seating configuration for vehicles with automated driving systems
(ADS) is a reclined seat that is rear-facing when in a frontal collision. There
are limited biomechanical responses and injury data for this seating
configuration during high-speed collisions. The main objective of this study
was to investigate thoracic and pelvic biomechanical responses and injuries to
male post-mortem human subjects (PMHS) in the rear-facing scenario with varying
boundary conditions.
Methods
Fourteen
rear-facing PMHS tests were conducted at two different recline angles (25 deg
and 45 deg) in 56 km/h frontal impacts. PMHS were seated in two different
seats, one used a fixed D-ring (FDR) belt, and one used an All Belts To Seat
(ABTS) restraint. A reinforcing frame that included load cells to quantify
inertial loading from the PMHS was installed behind the seat back of the OEM
seats. For thoracic instrumentation, strain gages were attached to ribs to
quantify strain and timing of fractures. A chestband was installed at the
mid-sternum level to quantify chest deflections. For pelvic instrumentation,
three accelerometers and three angular rate sensors were installed on each
iliac wing to quantify pelvic kinematics. Data from these thorax and pelvis instrumentation
were analyzed to determine injury mechanisms.
Results
Rib fracture
location, distribution, and frequency were quantified to understand the
influence of the seat, restraint type, and seat back recline angle. The PMHS
sustained more rib fractures in the 45-degree recline condition (average of 30
fractures for FDR and 12 for ABTS) than the 25-degree recline condition
(average of 16 fractures for FDR and 6 for ABTS). Four PMHS sustained
pubic ramus fractures due to eccentric inertial loading from the lower
extremities during the occupant's motion into the seat.
Discussion
The rib fractures
from the ABTS condition were not as symmetric as the FDR condition in the
25-degree recline angle due to a belt retractor structure located at one side
of the seat back frame. However, this was not as obvious as in the 45-degree
recline angle. Average peak chest compression occurred around 44 ms and 47 ms
in the ABTS and FDR conditions, respectively. Over 65% of the rib fractures
occurred after peak chest compression when the abdominal contents shifted
rearward and upward into the thorax due to the ramping motion of the PMHS. This
implies that most rib fractures likely occurred due to a combination of chest
compression and expansion with upward shear loading. PMHS with pubic ramus
fractures exhibited more extensive off-axis rotations (e.g., over 10 deg
rotation about the Z-axis) due to outward deformation of the pelvis. Since PMHS
responses and injury information in rear-facing high-speed impacts are very
sparse in the literature, these limited findings should assist to better
understand PMHS thoracic and pelvic injuries.
Conclusion
The thoracic and pelvic responses and
resulting injuries from this study will guide the improvement of FE human body
models and anthropomorphic test devices to better reflect occupant response in
rear-facing seat configurations during high-speed frontal impacts.
Paper No.23-0133-O
Comparison of injury
predictors and kinematics of Human Body Models representing average female and
male road users in car crashes.
Corina Klug, Christoph Leo TU Graz, Austria Johan Iraeus, Jobin John, I Putu
Alit Putra, Mats Svensson Chalmers University of Technology, Sweden Ines Levallois Faurecia, France Arne Keller, Linus Trummler Working Group on Accident Mechanics,
Switzerland Astrid Linder The Swedish National Road and Transport
Research Institute, Sweden
Research
The aim of the
study was to investigate the effect of gender-specific differences in
anthropometry for kinematics and injury risk in car occupant and vulnerable
road user (VRU) crashes.
Methods
The open-source
VIVA+ human body models (0.3.0) were used, which have been previously validated
on component and full-scale levels. The 50th percentile male (50M) and the VRU
models differ from the baseline, seated 50th percentile female (50F) model only
in terms of geometry (derived from regression models) and mass distribution.
Kinematics and injury predictors (head and neck criteria; strain-based rib and
lower extremity fracture risks) of the 50F and 50M VIVA+ models are compared
for five different crash scenarios: pedestrian/cyclist impacted by a car and
car occupant in rear/frontal/near-side impacts. For the VRU impacts, a generic
car front was used for simulation of collisions with 40 km/h at the vehicle
centreline. For the occupant simulations, a generic vehicle interior was used
for the frontal and side impacts, while a developed open-source seat model was
used for the rear-end impacts, which was validated with the novel Seat
Evaluation Devices (SET), matching the VIVA+ anthropometries. Generic crash
pulses representative for consumer-test load cases were applied. For the
rear-end impacts, real-world crashes with known injury outcomes were simulated
additionally. All tools and results described in the paper will be openly and
freely accessible.
Results
For the frontal
impacts, different interactions with the airbag and submarining are observed
for the female. Rib fracture risk was slightly higher in the female (10% higher
3+ risk), while brain injury risk was twice as high for the male. In the side
impact, higher (+20%) rib fracture and brain injury risk were observed for the
male. Differences in belt interaction caused higher strains for the female on
the non-struck side of the ribs. In the rear-end impacts, kinematic differences
between female and male were observed in all load cases. With the Euro NCAP
pulse, higher T1 peak accelerations and NIC values were observed in the
male. In the reconstructed real-world cases, no clear trend for NIC was
visible. In the VRU impacts, differences in impact locations were observed. The
strain-based assessment showed remarkable higher injury predictors for the
femur (e.g., 99% vs. 15% fracture risk for proximal femur), thorax (three times
higher risk) and pelvis for the 50F compared to the 50M.
Discussion
Material models
were not modified between the male and the female HBM. This enables to compare
geometric effects, but considering additional sex-specific effects (e.g. bone
density) could further increase the differences. NIC values did not
differ significantly between females and males nor between injured and
non-injured real-world cases, showing the need to consider alternative criteria
such as pressure transient in the cervical spinal canal, which showed better
correlation with the observed injuries. Further research is needed to map the
observed differences to injury risks.
Conclusion
Differences between the response of an
average female and male model were observed throughout all load cases. This
indicates a benefit of adding the average female anthropometry for safety
evaluations to ensure gender-equal protection.
PEER REVIEW Paper No.23-0140-O
The effect of follower
load on Lumbar Spine Flexion-extension response
Kalle Chastain,
Bronislaw Gepner, Jason Forman, Jason Kerrigan University of Virginia, United States Jason Hallman Toyota Collaborative Safety Research Center,
United States
Research
Reclined
occupants without knee restraint in frontal crash tests and computational
simulations have exhibited high magnitude combined axial compression and
flexion bending, and compression-flexion fractures of the lumbar spine have
been produced in sled testing with post-mortem human surrogates (PMHS).
We hypothesize that the mechanical response of the lumbar spine to flexion
loads is affected by superimposed axial compression. The goal of this study is
to measure the biomechanical response of the human spine in flexion and
extension bending both with, and without, a superimposed axial compression load.
Methods
A highly
repeatable 6DOF force/torque- and position-controlled robotic test device was
employed to subject seven PMHS lumbar spine (T12-Sacrum) specimens to combined
loading experiments. The device was modified to incorporate parallel closed-loop
feedback control of a follower load mechanism that applied and directed 0N,
900N, or 1800N of axial compression load along the curvature of the spine and
maintained the load while the robotic test device applied non-injurious pure
flexion and pure extension bending loading. The data collected include
force/moment data (from load cells) and 6DOF kinematics data for each vertebra
(using a stereophotogrammetric motion tracking system). The kinetic
(moment/angle) and kinematic (L3/L1 or L5/L1 rotation) responses of the
individual specimens were analyzed to evaluate variations across the sample for
each of the test conditions. These data were organized into biomechanical
response corridors to facilitate their use in evaluating biofidelity of anthropomorphic
test devices (ATDs) and computational human body models (HBMs).
Results
The lumbar spine
specimens exhibited a nonlinear kinetic response in flexion and a generally
linear kinetic response in extension in the absence of axial load. With
increasing axial compression load, the response in flexion became more linear,
and the responses in both flexion and extension showed increases in
stiffness. Kinematically, the deformations of the spines were asymmetric,
with the greatest intervertebral rotation occurring at L5-S1 in flexion, and
this locus of deformation moving to the L2-L3 joint in extension.
Discussion
We hypothesize
that these changes in response are due to axial compression causing greater
engagement of the lumbar's facet joints, which creates a parallel load path,
ligament unloading and intervertebral disc pre-stressing. The methodology
of the study was devised to isolate specific loading modes of the spine and for
the specific purpose of using the collected data to evaluate the response of occupant
surrogate models like ATDs and HBMs. However, because multiple directions
were assessed in multiple tests with the same specimens, the magnitudes of
loading were relatively low (+/-22.5 deg in flexion/extension), so this
analysis should be carried forward to loading magnitudes that approach failure
in the future.
Conclusion
The mechanical response of the lumbar
spine is affected by the presence and magnitude of axial compressive
load. Since the lumbar spine is subjected to substantial combined compression-flexion
loading in reclined frontal impacts, occupant surrogates like ATDs and HBMs
targeted to predict occupant response in such postures should ideally be able
to represent the complex loading response of the spine to facilitate their use
in predicting injury risk.
Paper No.23-0149-O
Injury risk estimation
in far-side impacts using small female and average male finite element human
body models
Karan Devane, Fang-Chi Hsu, Bharath Koya, Ashley Weaver, F. Scott
Gayzik Wake Forest University School of Medicine,
United States Matthew Davis, Berkan Guleyupoglu Elemance, LLC, United States
Abstract
Far-side crashes are the
second-highest, after near-side impact crashes, cause of MAIS 3+ injuries to
occupants for ΔV above 48 kph. The objective of this study was to estimate
and compare injury risks between a small female and an average male occupant in
far-side crashes using finite element human body models (HBM) in a simplified
vehicle environment. To study far-side crashes, 126 simulations were conducted
as a design of experiments (DOE) by varying lateral ΔV (10-50kph; 5kph
increments), the principal direction of force (PDOF 50°, 60°, 65°, 70°, 75°,
80°, 90°), and occupant model. Occupant models used were the Global Human Body
Models Consortium (GHBMC) 5th-percentile female (F05) and 50th-percentile male
(M50) simplified models (-OS) with a modular detailed brain (+B). Overall
skeletal structures are shared between the detailed and simplified models which
allows the modular use of detailed parts in simplified models. Models were
gravity settled and belted into a simplified vehicle model (SVM) modified for
far-side impact simulations. The far-side SVM (FSVM) has both driver and
passenger seats and door intrusion on the far side implemented. Acceleration
pulses and vehicle intrusion profiles used for the DOE were generated by
impacting a 2011 Camry vehicle model with a mobile deformable barrier model
across the 7 PDOFs and 9 lateral ΔV's in the DOE for a total of 63
additional simulations. The impacted surface of the Camry was instrumented to
measure relative displacement into the vehicle to generate an intrusion
profile. Injury risks were estimated for the head and chest (AIS2+; AIS3+) and
abdomen and pelvis (AIS3+). Overall AIS3+ injury risk for each occupant was
calculated using AIS3+ injury risk estimations for the head, chest, abdomen,
and pelvis. A Wilcoxon signed-rank test was used to test for significant
differences between estimated risks for F05-OS+B vs. M50-OS+B. Statistically
significant differences between F05-OS+B and M50-OS+B were found for AIS2+ risk
of head injury and AIS3+ risk of head, chest, and pelvis injury. No significant
differences were found for AIS3+ risk of an abdominal injury and AIS2+ risk of
chest injury. The overall risk of AIS3+ injury was higher for the M50-OS+B than
the F05-OS+B in 84% of cases. Injury risk increased with an increase in lateral
ΔV which was in agreement with studies found in the literature. An
investigation of injury risks associated with far-side crashes was undertaken
for both an average male and small female HBM. Differences observed in the
estimated injury risks suggest that occupant size should be taken into
consideration in safety system design. While this study used an FSVM with a
rigid center console and dashboard, the relative differences between models
were investigated. The effect of occupant size/sex on injury risk was
highlighted by differences in overall injury risk for small female vs. average
male HBMs. The study describes a method for simulating far-side crashes with an
SVM that can include an estimation of intrusion.
PEER REVIEW Paper No.23-0152-O
Analysis of injury
mechanism & thoracic response of elderly, small female PMHS in near-side
impact scenarios
John Bolte, Yun Seok Kang, Amanda Agnew The Ohio State University, United States Ben Shurtz Autoliv, United States Bengt Pipkorn Autoliv, Sweden Kevin Moorhouse, Heather Rhule National Highway Traffic Safety
Administration (NHTSA), United States
Research
In 2019, 7,214
occupants 65 and older were killed in car crashes in the United States, which
is a 31% increase for this age group since 2010. When compared to
occupants less than 65 years of age, older occupants are more frequently killed
in near-side crashes. Crash data has also revealed that for small,
older female occupants, thoracic related injuries are among the leading causes
of fatality. Historically, biofidelity response corridors and
injury criteria for small females have been determined by scaling values from
mid-size male data sets. In addition, the majority of past near-side
impact PMHS studies used a generic load wall to capture external loads that
were applied to PMHS. While these data were helpful in documenting
biofidelity, they did not represent a realistic response an occupant would
undergo in a near-side impact due to the lack of door intrusion, airbag
deployment and use of standard restraints with pretensioners. The
objective of this research was to test small, elderly female PMHS and 5th female
ATDs in a repeatable, realistic near-side impact crash scenario to look at the
appropriateness of the ATD and currently accepted injury criteria as they
relate to this vulnerable population.
Methods
Ten small,
elderly PMHS and both the SID-IIs and WorldSID 5th percentile ATDs were
subjected to a more realistic near-side impact loading
condition. The boundary conditions included an intruding driver's
side door that was controlled using the Advanced Side Impact System (ASIS)
(DSD, Austria) on a HYGE sled. The sled acceleration matched the acceleration
profile of an impacted vehicle, while four pneumatic cylinders of the ASIS,
covered by a typical door liner, produced realistic door intrusion. The PMHS were
targeted to be elderly females age 65+, approximately 5th percentile in
height and weight, with osteopenic areal bone mineral density. Each subject was
seated on a mass-production driver seat, equipped with a side airbag and
standard three-point restraint with a pretensioner. Instrumentation
on each PMHS included strain gages on ribs 3-10 bilaterally, to help identify
fracture timing. Two chestbands were used to measure chest deflection (on both
PMHS & ATDs), one at the level of the axilla and one at the level of the
xiphoid process.
Results
Injuries observed
were primarily rib fractures, particularly on the struck side, and in multiple
cases a flail chest was observed. Eight subjects resulted in AIS3+ injuries,
despite the ATDs predicting less than a 10% chance of AIS3+ injury.
Discussion
Subjects crossed
the threshold for AIS3 injury in the range of only 1% - 9% chest compression at
the level of the xyphoid process. Additionally, mechanism of injury varied, as
some injuries were incurred by door interactions while others came during
airbag interactions.
Conclusion
This research points to two areas of
concern that need to be further analyzed: (1) the appropriateness of simplified
PMHS testing to document injury thresholds and define injury criteria for complicated
crash scenarios; (2) the importance of understanding the timing of injuries to
better understand the use of current passive restraint systems.
Paper No.23-0183-O
Influence of time
constants and directional interaction of a kinematics-based brain injury metric
on its predictive capability of brain strain response in car crashes
Toshiyuki
Yanaoka Honda R&D Co., Ltd, Japan
Abstract
Among the studies focusing on criteria
for brain injuries induced by the rotational motion of the head, one of the
recent studies has compared the predictive capability of various injury
criteria proposed by different studies, with the results showing that the best
predictor depends upon specific impact configurations. This suggests the need
for a more robust injury criterion across a variety of impact configurations
with different duration of an impact event. The aim of this study is to
investigate the effect of incorporating additional time constants and modifying
directional interactions on the predicting accuracy of the physical model-based
criterion called CIBIC (Convolution of Impulse Response for Brain Injury
Criterion) proposed by the author's group. A Maxwell model was parallelly added
to the simplified physical model (standard linear solid) of the CIBIC criterion
to improve the time-dependent responses. One simplest candidate formulation of
the cross-terms was tried to replace the originally used root sum square to
combine the three components of the strain. The Global Human Body Models
Consortium (GHBMC) head/brain model was used to obtain the target response of
the maximum principal strain (MPS). A step function with the magnitude of
10,000 rad/s2 was used to optimize the spring and damping coefficients. The
spring and damping coefficients were optimized by maximizing the CORA
(CORrelation and Analysis) score. The modified CIBIC was further validated
against the GHBMC model using a total of 256 time histories of the head
rotational acceleration representing those of the four groups of load cases
(occupants in full-frontal, oblique-frontal and side impacts as well as
pedestrian impacts). The coefficient of determination calculated from the
correlation of peak MPS and the average value of the CORA score were compared
between the original and the modified CIBIC. The modified CIBIC with the
modified time constants was found to improve both assessment metrics for all of
the four groups of the load cases, while both assessment metrics predicted by
the modified CIBIC with the directional interaction was not improved. The
effect of the modifications shown by the modified CIBIC suggest that further
consideration of the directional interaction is needed to develop a robust
criterion, requiring thorough investigations on the method to combine the
responses of the three axes.
Paper No.23-0197-O
Test method for
developing updated neck biofidelity corridors for a small female occupant
Corina Espelien,
John Paul Donlon, Sydney Koerber, Sara Sochor, Kevin
Kopp, Brian Overby, Jason Forman University of Virginia, United States
Abstract
The continued development and
improvement of crash evaluation tools for a variety of anthropometries,
especially the small female, call for experimental testing to generate
anthropometric-specific biofidelity targets. The effect of active musculature
on head and neck response in impact loadings cannot be ignored, but data from
volunteer testing at impact severities performed in the 1960s and 1970s at the
Naval Biodynamics Laboratory (NBDL) is limited to the male response. To
generate biofidelity targets for the head and neck response of the small female
that include the effect of active musculature, modern testing must rely on
combining PMHS data from different anthropometries and retrospective analysis
of the original NBDL testing outputs and other volunteer studies. This paper
describes the methodology to replicate the original NBDL testing for small
female and average male PMHS for the purpose of informing new biofidelity
corridors for the 5th percentile female neck. Publications related to the
original testing were reviewed for qualitative and quantitative measures
detailing the setup of the NBDL configuration. A custom buck with an upright
seat (90° between seatpan and seatback), five-point rigid harness, footpan, and
tether head support system was designed and fabricated for use with an
acceleration sled. Of critical importance, the head and neck angle in the PMHS
tests will be matched to NBDL initial positioning of -0.9° for head and 20.75°
for neck. Two input pulse severities for frontal PMHS testing were chosen: a
low severity at 3g peak acceleration and a moderate severity at 8g peak
acceleration. These curves were chosen to avoid damage or injury to neck
structures and to investigate the head and neck response at multiple
severities. The boundary conditions on the sled will be measured via load cells
and the PMHS kinematics will be measured through bone-mounted instrumentation
packages and motion tracking arrays. This methodology will be used in
experimental testing of small females and average males in the NBDL frontal
impact condition.
Paper No.23-0242-O
The SAFER HBM – A human
body model for seamless integrated occupant analysis for all road users
Bengt Pipkorn Autoliv Research, Sweden Lotta Jakobsson, Jonas Östh Volvo Cars, Sweden Johan Iraeus Chalmers University of Technology, Sweden
Abstract
The development of the SAFER human
body model (HBM) started in 2008 and is still ongoing. SAFER HBM is an
omni-directional model that can be tuned and scaled (morphed) to correspond to
humans of different age, sex, weight, and stature. The model can be positioned
to the posture of occupants, pedestrians, bicyclists, motorcyclists etc. to
enable analysis of road users inside as well as outside the vehicle. SAFER HBM
is capable of predicting human kinematics in evasive maneuvers (low-g) as well
as in crashes (high-g). The capabilities also include injury risk predictions
in crashes. The model has been thoroughly validated and used in numerous
studies. Some examples: The effect of reversible pre-tensioning of the diagonal
belt on occupant kinematics and injury risk for pre-crash evasive maneuvers
followed by a crash, the influence of different postures and anthropometries on
occupant kinematics, and the injury reducing benefits of a helmet in bicyclist to
car impacts have been evaluated. Based on results from these studies, the SAFER
HBM is considered to be an efficient and biofidelic tool for development and
validation of protection systems for road users inside and outside the vehicle.
Paper No.23-0276-O
Comparison of
head-neck kinematics between isolated Finite Element (FE) head-neck model and
full-body model in low severity rear-end impact
I Putu Alit
Putra, Johan Iraeus, Mats Y. Svensson, Robert Thomson Chalmers University of Technology, Sweden Fusako Sato Japan Automobile Research Institute, Japan Astrid Linder The Swedish National Road and Transport
Research Institute, Sweden
Abstract
The objective of the present study was
to analyze whether the kinematics of an isolated head-neck model can replicate
those observed on a whole-body model in order to reduce simulation time in
development or optimization tasks. Previous studies have shown how muscle
controllers improved head-neck kinematics responses over a passive neck muscle
implementation. These studies used volunteer T1 displacement time histories
prescribed on the model T1 as the loading input to develop the neck controller
characteristics. It was not clear whether the implementation of a controller
based on volunteer kinematics with an isolated head-neck model was directly
transferable to a full-body model. The current study shows that the head-neck
model produced almost identical responses as the full body model for the first
200ms of the event for most kinematic variables. The head rotational
displacement corresponded well during the first 150ms. The isolated head-neck
model predicted more displacement and rotations than when mounted on a
full-body model. The current simplification of a head-neck model still produced
reasonable kinematic responses during the critical time period to assess soft
tissue neck injuries, making it suitable for developing and tuning neck muscle
controllers.
Tuesday, April 4, 2023, | 2:00‐6:00
Chair: Thomas Belcher, Australia | Co‐Chair: Cecilia Sunnevång, Sweden
TRACK B | Room: G304
Paper No.23-0033-O
The analysis of
mechanism and countermeasure for reducing thoracoabdominal injury risk caused
by far-side impact
Hitoshi Ida, Masashi
Aoki, Michihisa Asaoka, Yoshito
Kusuhara TOYODA GOSEI, Japan Ning Zhang TOYODA GOSEI North America, United States Shiro Ohara TGR Technical Center, United States
Abstract
The European New Car Assessment
Programme (Euro NCAP) added requirements in 2020 for the protection of far-side
occupants. This is because in a side-impact accident, serious injuries can
occur to passengers not only on the near (collision) side but also on the
counter-collision (far) side. Analysis of National
Automotive Sampling System/Crashworthiness Data System (NASS-CDS) far-side
accidents from 2002 to 2015 revealed that serious injuries occurred not only to
the head but also to the chest and abdomen. Liver injury accounts for 48% of
all abdominal injuries in occupants with seat belts and is a type of trauma
that must be noted in traffic accident lifesaving. For head
protection, the Euro NCAP test provides criteria for head movement, but no
method has been established to quantify liver injury. We attempted to quantify liver
injury by simulation using a human body model. The
simulation used the THUMS (Total HUman Model for Safety) human body model in
which the shapes of major organs had been modeled. First, the load-displacement
characteristics of the liver were modeled from the specimen level to those of
the whole organ. Using the liver model, we simulated the behavior of the body
in the far-side sled test performed by Pintar et al. and investigated the liver
injury index. We found the maximum principal strain in the
liver to range from 60% to 120% in the current model, resulting in laceration
of the liver. Using the human body model, we then clarified the injury
mechanism of the liver and examined how to reduce injury. In far-side
accidents, it was found that the injury was caused by the upper body being
catapulted toward the impact side. A simulation was
conducted to determine whether a load on the right side of the occupant to
prevent this sudden and forcible upper body could lessen liver injury.
Simulation results show that the maximum principal strain on the liver can be
cut from 120% to 60% by reducing the displacement of the tenth thoracic
vertebrae (T10), corresponding to the height of the liver, to within 190 mm on
the impact side.
Paper No.23-0283-O
Evaluation of THOR-50M,
WorldSid-50M and GHBMC
M50-O v6.0 Models in far-side
crashes
Jay ZHAO, Deepak Vasant Sabannavar, Mutaz Shkoukani Joyson Safety Systems, United States
Abstract
This study is conducted to assess
biofidelity of three occupant models (GHBMC human 50th%ile male occupant model
M50-O v6.0, Humanetics male THOR dummy model v1.8.1 and WorldSid-50M model
v7.6) in far-side crash test conditions and to better understand the kinematics
and response of a far-side mid-sized driver in a compact size vehicle crashed
to a 285° oblique right-side rigid pole at 31.01 km/h (NHTSA FMVSS 214 Test #
210915). Far-side occupant simulations for various sled and vehicle crash tests
have been conducted. Firstly, the GHBMC human body model (HBM) is correlated
with the three post-mortem human subjects (PMHS) far-side sled tests performed
by University of Virginia (UVA) [1] at two crash severities and two impact
directions. Secondly, a series of the far-side sled test simulations with
paired HBM and anthropomorphic test device (ATD) cases are conducted, varying
with severities and impact directions, seats, and central console presence.
Lastly, occupant simulations are performed for a belted far-side mid-size male
driver, represented by the HBM and the WorldSid-50M model respectively, in the
subject compact passenger car in the FMVSS 214 pole test. Comparative analysis
is made for the kinematics and responses of the HBM and the WorldSid-50M model
at the vehicle crash. The HBM correlation results show that the GHBMC M50-O v6.0
human model reasonably correlates well with the PMHS kinematics and response
from the 60-degree oblique far-side UVA sled tests. The HBM estimated high
injury risk for the thorax is in line with the post-test PMHS injury outcomes.
The comparative HBM-ATD studies at both the far-side sled tests and the vehicle
pole crash test indicate that both ATD models have positive and negative
biofidelity outcomes compared to the HBM. The THOR dummy has similar
head/neck/torso kinematic and response measures compared to the HBM under the
oblique sled test conditions, while its pelvis and lower leg respond poorly to
the lateral inertia loads. The WorldSid-M50 dummy model has the whole-body
kinematics similar to the HBM under the oblique sled test conditions, while it shows
stiffer lateral bending of the torso and smaller chest deflections than the HBM
especiallyunder
the lateral far-side loadings. The subject vehicle side crash test
occupant simulation with the HBM predicts that the mid-size male driver may
suffer severe injuries on the chest and moderate injuries on the head and
abdomen.
Paper No.23-0130-O
Factors of severe
injuries associated with side pole collisions based on field vehicle collision
investigation
Yeon IL Choo, Kang Hyun Lee, Joon Seok Kong, Oh Hyun Kim Center for Automotive Medicine Science
Institute, Yonsei University, Wonju College of Medicine, Republic of Korea Gil Won Kang Graduate School of Biomedical Convergence,
Chungbuk National University, College of Medicine, Republic of Korea Sang Chul Kim Department of Emergency Medicine, Chungbuk
National University, College of Medicine, Republic of Korea Kwang Soo Shin Graduate School of Healthcare Management, The
Catholic University of Korea, Republic of Korea<
Abstract
Side pole collision is the most
devastating road traffic injury (RTI) that causes death or severe injuries
among side collisions. Since pole-type materials have a relatively narrow width
and fixed rigidity, side pole collisions cause severe deformation and
consequent intrusion resulting in direct contact with the occupants. This study
aimed to investigate the risk factors that contributes to a severe injury of
motor vehicle occupants (MVOs) inside pole collisions. This study used the
Korea In-Depth Accident Study (KIDAS) database collected from 2011 to April
2020. Among the total data, we analyzed 392 patients who were engaged inside
collisions by excluding multiple collisions and rollovers. The collision type
was classified into pole and non-pole (i.e., vehicle-to-rigid wall) collisions
within a single collision. Moreover, we classified the collision severity
according to the amount of crush extent (CE) zones. In this study, the
incidence of non-pole collisions (n=362, 92.35%) was nearly 12 times higher than
pole-related collisions (n=30, 7.65%). Factors affecting severe injuries showed
statistical significance in the collision object (p<0.001), seat location
(p=0.001), and CE zone (p<0.001). However, passive safety devices, such as
seatbelts and airbags, showed no significance. In the case of side collision
objects, there were statistical differences between the chest (p=0.004),
pelvis, and extremities (p=0.016) between pole and non-pole side collisions.
Particularly, the highest risk of severe injury had dramatically increased
since the amount of CE zones was higher (odds ratio OR, 9.604; confidence
interval, 3.739–24.672). MVOs colliding with pole structural materials had the
risk of severe injury (ISS16+) in side collisions (OR, 5.285; 95% CI,
1.358–20.571). Compared with the far-side occupant, the near-side occupant had
increased risk of severe injury (OR, 3.123; 95% CI, 1.438–6.783). In this
study, factors affecting severe injuries in side collisions were identified as
the collision object, seat location, and crush extent. In frontal and rear-endcollisions, it is
necessary to seek weakness of crashworthiness caused by the lack of structural
performance (e.g., bumpers, engine room, truck leads) to protect occupants from
collision capacity in side pole collisions.
Paper No.23-0027-O
The effect of
microcars' lightness and compactness on safety in side impacts
Tetsuya
Matsushita, Takayuki
Shimizu, Shuichi Osato Autoliv Japan Ltd., Japan
Abstract
In this paper, the term 'microcar'
refers to a car which is categorized as L7 by the UN and conforms to the Ultra
Compact Mobility regulation in Japan. The car is much lighter and smaller than
a conventional passenger vehicle. It is generally understood that a microcar
has poorer crash safety performance than a conventional passenger car. In
particular, the microcar would seem to have a disadvantage in terms of
side-crash protection performance, since a smaller gap between an occupant and
the door means a shorter distance to absorb the impact energy. On the other
hand, having a lighter mass, it moves earlier when struck, meaning that the
speed and depth of the door intrusion is reduced: an advantage. Thus, the
severity of a microcar side crash is not obvious. The aim of this study is to
find out how the lightness and compactness of the microcar affect its
side-crash protection performance. This study was conducted using a numerical
simulation of a Japanese K-car full-vehicle model. Two kinds of parameters were
created. One is the Vehicle mass; the other is the Gap between the door inner
panel and an occupant. Three levels of mass were investigated (351 kg, 658 kg,
and 1000 kg) by removing parts which do not contribute to vehicle body strength
or adding weight to the center of gravity. The UN R95 load case was selected
for the evaluation. To simulate the microcar, the crash dummy and the seat were
repositioned outboard laterally from the original position, the seatbelt was
fastened without a pretensioner, and there was no airbag. The struck microcar's
velocity was obviously affected by its vehicle mass: the lighter the mass, the
sooner the vehicle moved after the Moving Deformable Barrier (MDB) impact.
However, the door velocity profile was almost the same in every vehicle mass
condition up to the time of the peak injury value, so the injuries were at the
same level—except for the head region, which was impacted by the roof rail. The
lighter vehicle produced the higher head impact velocity, resulting in higher head
injury values. As for the effect of door clearance, larger clearance seemed to
reduce the injury level—slightly but demonstrably. This study indicated that
the effect of vehicle mass (in the 358 kg–1000 kg range) on crash severity
seems to be very small for the chest-to-pelvis region. On the other hand, the
lighter vehicle mass seems to carry a higher injury risk for the head region. Thus,
it is suggested that the focus for microcars' side-impact safety should be on
protection performance for the head rather than the chest-to-pelvis area.
Paper No.23-0259-O
Lateral impact crash
tests for powered two-wheelers
Simona Roka, Genís Mensa, Victor Garcia Applus+ IDIADA, Spain Marco Pieve PIAGGIO, Italy Simone Di Piazza DUCATI, Italy Niccolò Baldanzini UNIFI, Italy
Abstract
Protection of the Powered Two Wheelers
(PTW) is a major concern due to the increase of this mode of transportation in
the accident statistics during the last years. In fact, nowadays, more than 12
riders die on European roads every day and more than 100 are severely injured.
In that scenario, IDIADA has promoted and coordinated the European project
PIONEERS within the H2020 EU funding programme. This project aimed to reduce
the number of PTW fatalities and severely injured by increasing the safety
performance, comfort, and usage rate of Personal Protective Equipment (PPE) and
the development of new on-board vehicle safety devices. To be able to evaluate
the effectiveness of the on-board vehicle safety devices, a lateral testing
protocol has been developed considering specifications of the sensor mounting,
fixing of the PTW into the test rig, etc. to ensure the repetitiveness of the
tests. Four lateral barrier (AE-MDB Euro NCAP) impact tests with two different
on-board systems have been performed within the scope of the PIONEERS project
according to the impact protocol defined. A Motorcycle Anthropomorphic Test
Device (MATD) has been attached to the upper part of a standard Hybrid III
dummy from IDIADA to perform the crash tests. Simulations have been performed
by UNIFI and compared with the physical tests performed in the laboratory.
Results show significant differences between the use of lateral airbag and
safety leg cover. The differences are observed not only in the biomechanical
values of the MATD but also in the kinematics of the PTW and dummy and in the
final relative position of both. By developing new test protocols, more
realistic and robust test methodologies will provide better physical data for
PTW manufacturers, as well as for on-board protective equipment OEMs (Original
Equipment Manufacturers) and PPE suppliers. The data from the tests can be
considered as a baseline for further development of the injury assessment for
PTWs and it's believed that this data will help to develop more sophisticated
testing devices. This paper covers the preparation of testing protocols and
execution of PTW lateral safety testing activities performed in IDIADA.
PEER REVIEW Paper No.23-0077-O
New load transfer
structure to reduce body deformation in side collision
This research
focused on the new IIHS MDB, which is closer to actual accident forms and has
been updated to higher-energy test standards. Conventional body structure
supports most of the load received from the barrier by bending deformation of
the door beams and B-pillar, and therefore, it is subject to large deformation
before the maximum load is reached. Reaction force generated by a part during
its bending deformation is often disadvantageous compared to the force
generated by its axial deformation, and the body deformation increases further
in a high-energy collision. Therefore, the objective of this research was to
construct new door beam and B-pillar structures that can increase the load from
the initial stage of the crash to reduce the body deformation.
Methods
The concept is to
transfer the lateral loads received from the barrier as axial loads in the
front-back and downward directions of the vehicle. The door beams were given a
bow-like shape with curvature toward the outside of the body. It will stretch-deform
on the front-back direction by the lateral input from the barrier. The
axial load generated in this process enhances the lateral load capacity of the
door beam. In addition, a load transfer mechanism is added in the lower section
of the B-pillar. It generates a downward axial load during the bending
deformation of the B-pillar, creating a new load path to the side sill and
increasing the lateral load of the B-pillar. Based on a C-category sedan in
mass production, the new structures were designed from theoretical calculations
and simulation.
Results
The designed door
beam and the B-pillar were fabricated and evaluated by a drop-test. It was
demonstrated that the generated load of the B-pillar was increased by 100% and
the load of the door beam was increased by 300% compared to the conventional
structure. A full-car simulation was also conducted with the new structure. It
was shown that a body deformation was reduced by 30%, a body intrusion velocity
by 40%, and a SID2S DUMMY G by 60%.
Discussion
The validity of
the concept was demonstrated by the fact that the door beam was crushed at the
front and rear ends due to its extension, while the mechanism added to the
B-pillar resembled downward crushing mode after the drop-test. As for the dummy
G reduction, the relationship is roughly consistent with the general theory
that G is proportional to the square of the door penetration rate. As the time
margin before the vehicle body collides with the occupant has been increased,
it is a future issue to further enhance safety by, for example, optimizing the
air-bag.
Conclusion
A new load-transfer structure was
proposed to increase the load from the initial stage of the crash and to reduce
body deformation. It is expected to be applied to EV, which requires a larger amount
of energy absorption, and to reduce injuries of the occupants, especially the
elderly.
Paper No.23-0282-O
A Comparison of
the SID-IIs ATD to the Global Human Body Model Consortium fifth percentile
female model in the Insurance Institute for Highway Safety (IIHS) updated side
impact crash test (Side 2.0)
Anthony
Dellicolli, Jeffery Dix Nissan North America, United States Russ Morris Autoliv North America, United States Benjamin Shurtz Autoliv North America, United States
Abstract
This paper will present a study
comparing the response of the SID-IIs Anthropomorphic Test Device (ATD) to the
Global Human Body Model Consortium fifth percentile female model (GHBMC F05
v5.1) in the Insurance Institute for Highway Safety (IIHS) updated side impact
crash test (Side 2.0). The study was conducted using a CAE model correlated to
a barrier crash test with a small SUV. The occupant kinematics as well as
injury response of the SID-IIs was compared to that of the Human Body Model
(HBM). The SID-IIs response generally agreed well with the human body model
except for clockwise pelvis Z-axis rotation resulting from the 'M-shaped' door
deformation pattern characteristic of the IIHS Side Impact 2.0 test;
additionally, the femur moment measured on the SID-IIs was significantly higher
than that measured in the HBM. A CAE model of a simplified bending test was
created to study the loading mechanism driving the femur moment responses and
clarify the reasons for the differences observed for the HBM and SID-IIs.
Through this study it was found that the SID-IIs hip allows for only 10-12
degrees plan view articulation before mechanical joint lockout occurs. In the
barrier test the clockwise pelvis rotation of the SID-IIs resulted in the
lockout of the hip joint on the SID-IIs. As a result, the femur moment
unrealistically increased exponentially compared to that of the HBM after hip
joint lockout occurred. As such the SID-IIs as currently designed does not
provide a biofidelic response for femur moments and pelvis rotation in the IIHS
Side Impact 2.0 test.
Paper No.23-0036-O
Crash simulations of
FMVSS No. 214 safety performance
Rudolf Reichert,
Cing-Dao (Steve) Kan GMU, United States
Abstract
Objective: Federal Motor Vehicle
Safety Standard (FMVSS) No. 214 requires doors in applicable vehicles to meet
minimum force requirements when subjected to a static load in addition to the
occupant protection requirements for the dynamic moving deformable barrier
(MDB) and vehicle-to-pole (VTP) side impact tests. This paper explores how
non-compliance of a single test condition affects the compliance and
performance of the other two tests. Additionally, potential dynamic
measurements that could be considered as a surrogate for the static test
procedure, are discussed. Methods: Validated FE models of a 2015 Toyota Camry
sedan, and a 2020 Nissan Rogue SUV were used to understand the mutual effect of
FMVSS-214 non-compliance. Modifications to the baseline model(s) were developed
that demonstrated non-compliance to the static test. Simulations were then
performed to evaluate how this affected vehicle and occupant responses in the
dynamic tests. The effect of MDB and VTP non-compliance on the respective other
two configurations were studied in the same manner. Measurements from the
dynamic tests, such as deformation metrics, accelerometer, and load cell force
data, were analyzed to determine if they can indicate performance in the static
door crush test. Results: Baseline simulation results showed FMVSS-214
compliance of the sedan vehicle for all three impact conditions. A first
modified FE model was developed by reducing the door beam strength, resulting
in non-compliance in the static test. Using this model, higher vehicle and
occupant metrics were observed in the dynamic tests, while still clearly
complying with FMVSS-214 requirements. A second and third modified FE model was
developed by mainly reducing the strength of B-Pillar and sill components,
resulting in non-compliance to the dynamic MDB and VTP conditions,
respectively. Reduced door strength was observed using these models in the
static test, while complying with FMVSS-214 static requirements. Limited
correlation between measurements from the dynamic tests and door strength in
the static test was observed Discussion and Limitations: The three FMVSS-214
configurations engaged different main load paths. Door beam strength was most
relevant for the static test but did not significantly affect performance in the
dynamic tests. B-Pillar and sill strength were most relevant for the MDB and
VTP tests, respectively, but did not notably affect performance in the static
test. The static door crush test impactor does neither overlap with the
B-Pillar nor the sill. Similar results with respect to the static door crush
test were observed using a validated FE model of a 2020 Nissan Rogue SUV. Since
two specific vehicles representing the sedan and SUV categories were used,
conclusions can not necessarily be generalized for other vehicles. Conclusions:
The research is relevant to understanding side impact performance measures.
Structural vehicle modifications that resulted in non-compliance for the
FMVSS-214 static test did not cause non-compliance in the dynamic MDB and VTP tests,
and vice versa. There are significant limitations of using dynamic performance
measurements from the dynamic tests as a surrogate for the static test due to
the different main load paths engaged by the respective FMVSS-214
configurations.
Tuesday, April 4, 2023, | 2:00-6:00
Chair: Lori Summers, United States | Co-Chair: Philippe Vezin, France
TRACK C | Room: G301+G302
Paper No.23-0070-O
Introducing a qualification
scheme for virtual test environments for driving automation systems
Siddartha
Khastgir, Albert Wallace, Paul Jennings WMG, University of Warwick, UK, United
Kingdom Benoit Anctil, Peter Burns, Dominique
Charlebois Transport Canada, Canada Simon Brewerton Aurrigo Driverless Technology, United Kingdom Research
Due to the large
number of scenarios that will be needed to be executed for the testing of
Driving Automation Systems (DAS), virtual testing will be essential to generate
evidence to prove the safety of the DAS. For that to happen, it is a
prerequisite that the virtual test environments (VTE) can be trusted and
produce results that are representative of real-world testing. While efforts
have begun at various international regulatory forums like UNECE (VMAD SG2) to
create a credibility assessment framework, a detailed methodology for proving
the trustworthiness of VTEs is missing in industry. This paper aims to
introduce an initial qualification scheme for VTEs by comparing the outputs of
real-world and virtual sensor models.
Methods
Drawing
inspiration from the credibility assessment framework developed by UNECE VMAD
SG2 working group, the fidelity of the VTE used for testing a DAS will need to
be a function of the system-under test (i.e., the Operational Design Domain
(ODD), test objective and the scenarios being used for the test). A scenario
execution in a VTE will have two main aspects: 1) static elements (e.g.,
buildings, trees, roads etc.) and 2) dynamic elements (e.g., pedestrians,
vehicles, cyclists, other road users). Factors like weather will impact the
DAS' sensor suite's ability to detect these entities. Our proposed methodology
compares the output of the real-world sensors and the virtual sensor models
(created in simulation). As a result, the sensor outputs for static and dynamic
elements are compared separately. A similarity metric is then calculated
between the real-world outputs and virtual sensor outputs for both static and
dynamic elements.
Results
We have developed
metrics for comparing point-clouds from real-world LiDAR sensor and virtual
LiDAR sensor when used in a different ODDs. The methodology has been
implemented with LiDAR sensor in multiple configurations (vehicle speed and
LiDAR rotation speed). As a result, we have created a qualification scheme
which compares the output of sensor models (real and virtual) as a function of
the ODD of the DAS.
Discussion
The proposed
methodology has been undertaken for a LiDAR sensor (real-world and virtual).
However, further work is needed to perform a similar comparison for other
sensors (e.g., camera and radar). Furthermore, while a novel approach has been
developed to compare sensor outputs (real-world and virtual), thresholds for
similarity / dissimilarity will need to be agreed as standards and / or
industry best practices.
Conclusion
We present a novel qualification
scheme for virtual test environments which has the advantage of combining the
fidelity of the simulation environment and sensor model into a single
qualification metric. The proposed approach verifies the VTE quality using the
fidelity of the sensor response as it is fundamental to the DAS operation. Many
VTEs exist which aim to focus of their photorealistic nature. However, none of
them consider the fidelity of the sensors' output in the VTE. We have chosen
the session on “Driving Automation Systems" as simulation-based testing of DAS
will be critical in the safety assurance process, including qualification of
virtual test tools.
PEER REVIEW Paper No.23-0080-O
Implications of the
positive risk balance on the development of automated driving
Felix
Fahrenkrog, Ludwig Drees, Florian
Raisch, Moritz Werling BMW AG, Germany
Research
Automated driving
(AD) from SAE level 3 represents a paradigm change from human driver
controlling the vehicle to a technical system controlling it. In this light
different regulatory bodies (European Commission, Germany, etc.) have defined
ethical guidelines for the operation of such a system. One core principle of
these guidelines is that the automated operation needs to be at least as safe
as the human driving – often referred to as the “positive risk balance".
However, these guidelines stay on a general level and do not provide any
details on what this means in a practical sense. This paper will provide a
practical approach to consider such ethical requirements.
Methods
Starting from a
detailed analysis of corresponding guidelines and a literature review of
possible risk assessment frameworks, a comprehensive approach has been
developed to consider such ethical requirements for the development of AD. This
approach covers different development stages. For the reporting of the work the
PROACT-URL approach has been chosen. The different steps of the approach are
demonstrated by an exemplary AD system.
Results
The paper will
present the approach developed by BMW to ensure that AD achieves a positive
risk balance for an AD system. The approach will be presented and discussed in
detail per development stage (concept phase, AD development phase, verification
& validation phase, post SOP phase). In the concept phase the scope is on
defining how good a human driver is and how good an AD needs to be. For this
purpose, accident databases need to be evaluated. In the AD development first
the relevant system requirements need to be derived. Here, Monte-Carlo
Experiments in combination with Bayesian Nets are applied. The fulfillment of
these requirements is later checked in the verification phase through simulations,
test track and real-world tests. For the validation of the risk balance the
safety impact of the AD in terms of traffic safety is derived by means of
simulation. The post SOP covers the field of field observation. For each stage
practical examples by means of the exemplary AD will be given.
Discussion
The approach is
not a single solution to ensure the safety of AD, but it adds to already
existing development processes in the context of vehicle safety (functional
safety, SOTIF etc.). The relationship with existing safety standards is going
to be discussed in the paper.
Conclusion
The safety of AD is paramount when it
comes to its operation and ensuring trust in this technology. The described
approach contributes directly to building this trust by a comprehensive
consideration of the principle of a positive risk balance throughout the
development in addition to existing safety standards.
Paper No.23-0110-O
Characterization and
mitigation of insufficiencies in automated driving systems
Yuting Fu, Jochen Seemann, Tim Beurskens, Andrei Terechko, Emilia Silvas NXP Semiconductors, Netherlands Caspar Hanselaar, Maurice Heemels Eindhoven University of Technology,
Netherlands
Abstract
Automated Driving (AD) systems have
the potential to increase safety, comfort, and energy efficiency. Recently,
major automotive companies have started testing and validating AD systems (ADS)
on public roads. Nevertheless, the commercial deployment and wide adoption of
ADS have been moderate, partially due to system functional insufficiencies (FI)
that undermine passenger safety and lead to hazardous situations on the road.
In contrast to system faults that are analyzed by the automotive functional
safety standard ISO 26262, FIs are defined in ISO 21448 Safety Of the Intended
Functionality (SOTIF). FIs are insufficiencies in sensors, actuators, and
algorithm implementations, including neural networks and probabilistic
calculations. Examples of FIs in ADS include inaccurate ego-vehicle
localization on the road, incorrect prediction of a cyclist maneuver,
unreliable detection of a pedestrian in rainy weather using cameras and image
processing algorithms, etc. The main goal of our study is to formulate a
generic architectural design pattern, which is compatible with existing methods
and ADS, to improve FI mitigation and enable faster commercial deployment of
ADS. First, we studied the 2021 autonomous vehicles disengagement reports
published by the California Department of Motor Vehicles (DMV). The data
clearly show that disengagements are five times more often caused by FIs rather
than by system faults. We then made a comprehensive list of insufficiencies and
their characteristics by analyzing over 10 hours of publicly available road
test videos. In particular, we identified insufficiency types in four major
categories: world model, motion plan, traffic rule, and operational design
domain. The insufficiency characterization helps making the SOTIF analyses of
triggering conditions more systematicand comprehensive. To handle faults,
modern ADS already integrate multiple AD channels, where each channel is
composed of sensors and processors running AD software. Our characterization
study triggered a hypothesis that these heterogeneous channels can also
complement each other's capabilities to mitigate insufficiencies in vehicle
operation. To verify the hypothesis, we built an open-loop automated driving
simulation environment based on the LG SVL simulator. Three realistic AD
channels (Baidu Apollo, Autoware.Auto, and comma.ai openpilot) were tested in
the same driving scenario. Our experiments suggest that even advanced AD
channels have insufficiencies that can be mitigated by switching control to
another (possibly less advanced) AD channel at the right moment. Based on our
FI characterization, simulation experiments and literature survey, we define a
novel generic architectural design pattern Daruma to dynamically select the
channel that is least likely to have a FI at the moment. The key component of
the pattern does cross-channel analysis, in which planned trajectories and
world models from different AD channels are mutually evaluated. The output of
the cross-channel analysis is combined with more traditional fault detections
in a safety fusion component. The safety fusion then feeds an aggregated
per-channel safety score to the high-level arbiter, which eventually selects
the AD channel to control the vehicle. The formulated architectural pattern can
help manufactures of autonomous vehicles in mitigating FIs.
Paper No.23-0119-O
Evaluation of safety
and mobility around low-speed autonomous vehicle through real world deployment
in urban roadway system
Abhijit Sarkar,
Vaibhav Sundharam Virginia Tech Transportation Institute,
United States Kevin Grove American Trucking Associations, United States
Abstract
Low-speed automated vehicles (LSAVs)
are a new type of road transportation option that can be deployed in densely
populated areas to connect passengers to existing transit systems. These
vehicles are designed to operate at low speeds (often in the < 25 mph range)
in complex operational design domains and can be retrofitted to accommodate
at-risk road users, thereby making transportation even more accessible. Also,
as many LSAVs are electric vehicles, they also show great potential for
benefiting the climate. Even though there are numerous benefits to deploying
LSAVs, several hurdles must be overcome to achieve success. For example, it is
unclear how an LSAV deployed in a regular lane with a 25 mph or higher speed
limit may affect other traffic. Also, it is unclear how vulnerable road users
like pedestrians and bicyclists behave around LSAVs, as human machine
interfaces for such interactions are not yet properly developed. These
variables pose multiple questions for the safety, mobility, and operation of
LSAVs in unrestricted operational domains. For example, an LSAV's low speed may
cause other vehicles to operate at a lower speed, causing more vehicles to
queue behind it. This may also make some drivers frustrated and lead them to
become involved in dangerous driving situations like overtaking and cut-ins. In
this work, we studied real world deployment of an LSAV on the US roadway to
understand driver behaviors via 360 degree camera views from cameras installed
on the LSAV. We examined the problems encountered during the deployment of an
EasyMile (EZ-10) LSAV. We specifically investigated events from a real-world
deployment during which the EasyMile LSAV needed to stop. The EasyMile
deployment studied in this work included cameras that captured the 360 degrees
of roadway environment around the vehicle. We developed a scene perception
algorithm using computer vision technology to track other roadway agents like
cars, pedestrians, and bicyclists around the EasyMile LSAV. We used object
detection and tracking algorithms to track the trajectories of each of the
roadway agents. Then we used perspective geometry and camera specifications to
find the relative distances and speeds of these agents with respect to the
EasyMile. This helped us understand the configurations of the traffic around
the LSAV and study other drivers' temporal behavior. For example, the collected
data shows the approach of any vehicle towards the EasyMile. Finally, we used
this information to study other vehicles' maneuvers and show how the information
from the cameras can be used to study simple maneuvers of other vehicles such
as cut-ins, lane changes, and following behavior.
Paper No.23-0128-O
Investigation on the
conditions for disturbances in the safety performance assessment on the
perception function of automated driving vehicles
Masao Nakagawa,
Tetsuya Niikuni, Hiroyuki Yamamoto National Traffic Safety and Environment
Laboratory, Japan
Abstract
This study focuses on perception as a
fundamental part of the function chain of automated driving systems. The
dynamic control of automated driving vehicles will be operated based on the
perception function resulting from processing information gathered by sensors.
Factors influencing perception should be identified and determined for the safety
performance assessment because such factors consequence the behavior of
automated driving vehicle. Especially, the characteristics of radar on
perception function in ADS was investigated, and conditions for disturbances to
developing safety performance assessments was discussed.
Paper No.23-0150-O
Evaluating and rating
the safety benefits of advanced vehicle technologies: Developing a transparent
approach and consumer messaging to maximize benefit
Bruce Mehler, Pnina Gershon, Bryan Reimer Massachusetts Institute of Technology, United States
Abstract
In 2012, a major traffic safety
organization tasked the MIT AgeLab with developing a data-driven system for
rating the effectiveness of new technologies intended to improve safety. Such a
system was envisioned as having the potential to educate and guide consumers
towards more confident and strategic purchasing decisions, ideally encouraging
adoption of technologies with demonstrated safety benefit. In addition, an
evaluation of the status and extent of existing data was seen as a way of
identifying research gaps in the state of knowledge about safety systems. The
focus was on technologies as a class, not on a rating review of individual
vehicle model implementations. As conceptualized, the system aimed to
complement traditional NCAP style ratings as well as to provide consumers with
transparent information on early stage and often improving safety technologies.
Development of the rating system and identification of data was undertaken in
consultation with a range of academic, industrial, consumer, NGO, and
governmental experts as well as with representatives of many of the major
automotive manufacturers and suppliers. A key observation that emerged was that
data on objectively demonstrable real-world benefits were generally sparse and
often lower than expectations based on theoretical considerations, simulation
studies, or pre-production evaluations. A number of experts and industry
representatives expressed some surprise at both the divergence between
theoretical and observed benefits and the relative scarcity of data upon which
to make objective assessments, while others were quite aware of these issues
and the need for the development of objective data under real-world operating
conditions. A number of factors that might be relevant to understanding why
such differences between expected and observed benefits exist were identified.
One outcome of this effort was the founding of the Advanced Vehicle Technology
(AVT) consortium to collect and examine objective data under naturalistic
driving conditions of how drivers interact with, engage, or don't engage,
various production safety and driver assistance systems. This ongoing effort is
contributing to insights concerning actual benefits and reasons for benefit
gaps. Drawing from our initial work, as well as newer sources of data, we argue
that the evaluation and rating of safety and driver assistance technologies for
informing the consumer and the public at large should consider both theoretical
potential and existing demonstrated benefit of specific technologies. This
position is increasingly relevant as the effectiveness of many newer
technologies have the potential to actually improve over the lifecycle of a
vehicle through software updates. The emphasis on ratings based on observed
benefit for actual drivers under real-world conditions is proposed to be
complementary, rather than competing with, ratings focused largely on
controlled test track evaluations of engineered capability. In addition, a case
is made for providing ratings that assesses benefit relative to overall crash,
injury, and fatality rates – and in relation to the specific scenario / crash
event type that a given technology is intended to address. This approach should
aid consumers in considering the extent to which a specific technology is or is
not relevant to their particular driving needs.
Paper No.23-0160-O
A method for the
characterization of perception sensors
Loren Stowe, Greg Beale, Matthew Palmer Virginia Tech Transportation Institute, United States Steven Huggins Global Center for Automotive Performance Simulation,
United States Sebastian Silvani National Highway Traffic Safety Administration (NHTSA),
United States
Abstract
Vehicle perception systems for both
advanced driver assistance systems (ADAS) and automated driving systems (ADS)
rely on a plurality of sensors and sensor modalities to “see" the surrounding
environment. Each sensor type has its own inherent strengths and weaknesses
(e.g., cameras perceive color but need ambient light, radar is insensitive to
light but does not perceive color). The goal of this study was to develop
systematic and adaptable tests and analysis methods that would allow the
performance characterization for a variety of sensors and sensor types. Three
common sensor modalities (radar, LiDAR, and camera) were selected for
demonstrating the application of the methodology. Three test maneuver templates
were developed to exercise the relative motion of target objects within the sensor's
field of view (FOV). These allowed a broad set of conditions to be
configured that corresponded to ones that might occur during real-world
driving. These were combined with external conditions (e.g., simulated
rain, variable ambient light, sensor degradations) to identify compounding
factors that may affect sensor performance. Sensor characteristics and test
factor sensitivities were then calculated across different metrics, including
distance accuracy and maximum detection range, to demonstrate the process and
efficacy of the method in characterizing perception sensor performance.
Paper No.23-0251-O
Evaluation of
different ADS material concepts using various safety metrics
Rudolf
Reichert, Chung-Kyu Park, Steve Kan George Mason University, United States William Hollowell WTH Consulting LLC, United States
Abstract
Research Question/Objective: New
vehicle concepts of occupied and un-occupied Automated Driving Systems [(U)ADS]
are fast evolving. Their design, materials used, and energy absorbing
structures can significantly differ from traditional vehicles. Appropriate
analysis methods and safety metrics can help to evaluate their crashworthiness
and compatibility when colliding with other vehicles or road-side hardware.
This paper explores the effect different material concepts of an ADS vehicle's
outer body has on self-protection and partner protection. The research is
considered an example to demonstrate how various impact configurations and
simulation analysis tools and metrics can be used to assess structural and
occupant aspects for this new type of vehicle class. Methods and Data Sources:
Previously developed Finite Element (FE) models of generic ADS vehicles in
combination with validated road-side hardware, crash barrier, and occupants
were used to understand the effect different material concepts can have on self-
and partner-protection. Partner-protection was analyzed using EuroNCAP's mobile
progressive deformable barrier (MPDB) and its respective compatibility metric
Occupant Load Criterion (OLC), where lower values represent better
compatibility. Self-protection was studied using occupant injury metrics
recorded during a run-off road impact scenario, where the ADS vehicles impacted
a New Jersey Barrier (NJB). Results: Differences in crash compatibility were
observed depending on the material concepts used. The impact of a mid-size ADS
vehicle using thermoplastic material for select components with the MPDB
resulted in an OLC value of 18. The same vehicle with a composite material
concept showed anOLC
value of 19, while an OLC value of 22 was recorded for the baseline vehicle
with a steel material concept. Differences in occupant metrics HIC, BRIC, chest
deflection, and femur loads were small when comparing the three material
concepts in a 35-mph oblique impact into an NJB. Discussion and Limitations:
The use of different material concepts resulted in different total vehicle
mass. The vehicle using thermoplastic material for select components had a mass
of 3,653 kg. The same vehicle with composite material concept had a mass of
3,718 kg, while the baseline vehicle using steel had a mass of 4,273 kg. Lower
vehicle mass correlated with better partner-protection based on OLC metrics.
Occupant metrics were mainly affected by the interior concept, which was
identical for all three vehicles. Differences in occupant load was therefore
small. The same vehicle design and underlying structure was used during this
study and no optimization towards the respective material concept was
performed. Conclusions and Relevance to Session Submitted: The research is
relevant to demonstrate how simulation tools can contribute to assessing this
new type of ADS vehicle class. Material concepts that resulted in a smaller
vehicle mass tended to show better partner protection. The interior concept,
which was the same for all three ADS vehicle variations, was the main factor
for producing similar occupant injury metrics for the evaluated impact
scenario.
Paper No.23-0274-O
Safety grading scheme
for highway assisted driving technology
Dominic
Tough, Colin Grover, Matthew Avery Thatcham Research, United Kingdom
Abstract
There is increasing availability of
assisted driving technology on vehicles and manufacturers are developing
innovative features and functionality. When the driver engages assisted driving
technology, the vehicle supports the driver with the steering and speed
control, however the driver retains the responsibility for the safe driving.
Assisted driving offers the potential safety benefits of improved speed and
headway regulation and lane guidance, addressing the most common front-to-rear
crash type and lane drifting and run-off road crashes. Because the systems
relieve some of the driving workload, fatigue is also addressed. However,
system implementation must be carefully considered to ensure the driver remains
engaged with the driving task. Assisted driving systems are implemented
differently by individual vehicle manufactures. The objective of this research
was to identify the key features that lead to safe implementation of assisted
driving technology, enabling the development of a consumer safety grading
scheme to guide vehicle manufacturers to safe implementation and provide an
independent, objective means of assessing systems. Vehicle Assistance and
Driver Engagement were identified as the two critical aspects. The level of
assistance provided must be matched by the perception of the driver and the
ability of the system to keep the driver engaged. Vehicle Assistance assesses
the steering support technology and the selection and application of
appropriate speed control. Driver Engagement assesses driving collaboration,
driver monitoring and system status in use, and also the consumer information
including how the system is named, marketed and its appropriate usage
described. A third key area identified for safe implementation was Safety
Backup, namely the advanced emergency supports the system provides in case of
an imminent collision beyond the capability of the assistance, in case of anunresponsive
driver who becomes disengaged for a long period, or a system failure. The
research was implemented by developing test and assessment protocols in
association with Euro NCAP acknowledging the results of broad range of research
vehicle testing. A four-tier grading scheme was developed (Entry, Moderate,
Good and Very Good) ranking vehicles on the sum of Assistance Competence
(balancing Vehicle Assistance and Driver Engagement) and Safety Backup. To
date, 21 vehicles have been assessed and a range of results have been achieved
that span across the four grades, indicating the relevance of the scheme and
its ability to differentiate systems. The scheme has identified an apparent
imbalance between Vehicle Assistance and Driver Engagement in one case. In
another, a vehicle has been reassessed and gained an improved grading after an
over-the-air update. A limitation of the grading scheme is it is currently
focused on highway functionality, whereas assisted driving technology can be
utilised by the driver wherever the system deems it is capable of operating. In
this first iteration of the grading scheme, only interaction on highway-like
roads with other restricted vehicle types has been considered. Expanding the
assessment beyond highway usage will necessarily involve assisted driving
relevant interactions with a broader range of road types and features, traffic
control and road users etc.
Paper No.23-0280-O
Proposal for an in-use
safety and security monitoring framework for Automated Vehicles (AV)
William Perren,
Kostas Kourantidis, Ben Simpson, Craig
Arnold Transport Research Laboratory (TRL Limited),
United Kingdom Bryn Balcombe ADA Innovation Lab Ltd., United Kingdom Nick Reed Reed Mobility Ltd, United Kingdom Sam Chapman The Floow Ltd, United Kingdom
Abstract
The UK government are committed to
bringing forward legislation to allow the safe and secure deployment of
self-driving vehicles, as set out in the recent policy paper, “Connected and
automated mobility 2025: realising the benefits of self-driving vehicles". As
part of the Connected and Automated Vehicle Process for Assuring Safety and
Security (CAVPASS) programme, TRL was commissioned to propose a concept for
assuring the safety of Automated Vehicles (AVs) throughout their operational
life. The work involved developing technical, procedural, and administrative
approaches for safety incident identification, investigation and reporting
based on an evidence review of current and proposed in-vehicle datasets, safety
metrics and collision investigation methodologies and supported by expert
judgment. A Hazard Analysis and Risk Assessment (HARA) and an analysis of
domestic traffic rules was conducted to assess the monitoring coverage of
relevant risk events. Based on these activities, an overall framework for
in-use safety and security monitoring has been proposed. The study identified
the need to monitor compliance against the behavioural competencies and safety
arguments stated prior to deployment in order to continually assess the performance
of the AV and the validity of the safety case during operation. A taxonomy for
event classification has been developed to specify events to monitor safety and
rules compliance. The study proposes that event-based data capture is the most
feasible method of capturing data required to understand event context and
causation to enable investigation. A minimum dataset specification has been
developed which specifies a set of data metrics and thresholds for event
detection as well as the data to be recalled supporting incident investigation.
The HARA found that the proposed measures could not cover all safety relevant
events and data sources external to data processed by the AV are required.
Therefore, a set of operational processes for monitoring have been proposed. A
concept for monitoring traffic rules compliance has been introduced whereby AV
perception data is processed independently. Analysis of domestic traffic rules
identified requirements to record relevant dynamic objects, static objects, and
AV behaviours to enable monitoring of rules compliance. Processes for in-depth
investigation and data analysis have been developed to enable the
identification of compliance issues, produce learnings to be shared across the
industry, and continuously improve the safety scheme. In-use monitoring data
was found to be vital in ensuring accountability of AV safety performance by
the manufacturer and contributes to an open and transparent safety culture by
enabling just and proportionate regulatory sanctions to be applied. Due to
their paucity, data from AV collisions could not be used to base monitoring
approaches on. The approach taken in this work was to identify safety
monitoring protocols based on known approaches from conventional driving and
other transport domains. A principle of continuous improvement was proposed
such that the accuracy, quality, and relevance of the monitoring framework can
be assessed through AV deployment. This independent study proposes a framework
for the safety performance assessment of AVs during operation to provide
regulatory oversight, accountability and improve public trust in the
technology.
Paper No.23-0032-O
Harmonized approaches
for baseline creation in prospective safety performance assessment of driving automation
systems
Peter Wimmer VIRTUAL VEHICLE Research GmbH, Austria Olaf Op den Camp TNO, Netherlands Hendrik Weber Institute for Automotive Engineering (ika), RWTH Aachen University,
Germany Henri Chajmowicz LAB, France Michael Wagner Continental Business Area Autonomous Mobility, Germany Jorge Lorente Mallada Toyota Motor Europe NV/SA, Belgium Felix Fahrenkrog BMW AG, Germany Florian Denk THI - CARISSMA Institute of Automated Driving, Germany
Abstract
In the last years, virtual simulations
have become an indispensable tool for safety performance assessment of driving
automation systems (DAS) and pre-crash technologies which are part of advanced
driver assistance systems (ADAS). Different approaches and tools are used in
this domain, making comparison of results of different studies difficult.
Therefore, the P.E.A.R.S. (Prospective Effectiveness Assessment of Road Safety)
initiative was founded to harmonize methods for prospective safety performance
assessment and by this make results of such studies more trustworthy and
comparable. One essential pillar of such a harmonization is the establishment
of the baseline, the set of data to which the performance of the technology
under study is compared to when performing prospective assessments. Various
ways have been presented in literature for setting up a baseline. For
harmonization, these ways need to be analyzed and categorized so that
recommendations can be given on when and how to use a certain baseline approach.
The research objective of this paper is first to develop general approaches to
establish a baseline based on existing ways and second to identify areas of
application for each baseline approach. Based on existing ways, we defined
general approaches for setting up a simulation baseline. These baseline
approaches can structure all existing ways based on their characteristics and
requirements and impacts on safety performance assessment results. Relevant
information for each baseline approach is discussed, such as the used data
type(s), data processing steps, applied variations to the original data,
application of simulation models, and statistical methods, etc. We identified
three types of baseline approaches: A) Using concrete real-world scenarios without
modifications. B) Using modifications of concrete real-world scenarios. Here,
real-world scenarios are the basis, but some of the existing measured
properties are altered or even new properties are added. C) Creating synthetic
cases where more general data such as distributions of relevant parameters
(e.g., from collision, road user behavior, traffic data) and mechanisms
possibly leading to collisions are used. The paper will provide examples for
each baseline approach. The three approaches can be clearly distinguished and
should be able to cover the generation of a baseline for all studies in the
field of prospective safety performance assessment. Each of the approaches has
its pros and cons, e.g., with respect to their representativeness, and the effort
to obtain the required data. Also, the evaluation objective to be addressed
needs to be considered when selecting an appropriate baseline approach as it
has a strong influence on this selection. The categorization of the three
approaches allows for defining common recommendations on when to use which
approach. By the baseline approaches presented, P.E.A.R.S. contributes to the
harmonization and acceptance of virtual safety performance assessment of
driving automation systems (DAS) and pre-crash technologies. This will greatly
enhance trustworthiness, comparability and, transparency of results of
prospective safety performance assessments.
Paper No.23-0064-O
Validation and plausibilization
of X-in-the-Loop tests for driving automation
Felix Reisgys, Johannes Plaum, Andreas Schwarzhaupt Daimler Truck AG, Germany Eric Sax Institut für Technik der Informationsverarbeitung,
Germany
Abstract
Virtual X-in-the-Loop (XiL)
environments are gaining significant importance in the test of Advanced Driver
Assistance Systems (ADAS) and Automated Driving Systems (ADS). In order to
derive reliable test results, credibility of XiL environments must be evaluated
using suitable methods for XiL validation. This typically involves a
back-to-back comparison to reference proving ground (PG) tests. Due to
uncertainties inherent to PG and XiL, this validation requires the analysis of
multiple test executions. Since this may not always be feasible with limited
data availability, we define plausibilization as a preliminary step towards
validation, comparing two single test executions in PG and XiL. A
plausibilization method is presented, combining the evaluation of pass/fail
criteria (PFC) and scenario distance measures. Finally, the application of the
method in an ADAS series development project by evaluating three example
Software-in-the-Loop (SiL) scenarios confirms that this is a reasonable
plausibilization approach. Furthermore, it is shown that the method can be
adjusted in a flexible way to meet requirements from different automation
levels, systems, or scenarios.
Wednesday, April 5, 2023, | 08:30-12:30
Chair: Kevin Moorhouse, United States | Co-Chair: Atsuhiro Konosu, Japan
TRACK A | Room: G303
PEER REVIEW
PAPER
No.23-0041-O
Biofidelity assessment
of 5th Percentile Female ATD abdomen responses relative to recently developed
belt and bar loading corridors
Rakshit
Ramachandra, Laura Watkins Transportation Research Center Inc, United
States Jason Stammen, Erin Hutter, Kevin
Moorhouse National Highway Traffic Safety Administration (NHTSA),
United States
Research
Quantitative
evaluation and comparison of the THOR-05F and Hybrid-III-05F ATD abdomen
responses when subjected to PMHS belt and bar loading conditions.
Methods
Both ATDs were
subjected to two different loading conditions: fixed-back belt pull at 4 m/s
and free-back rigid bar impact at 6 m/s. The stroke of the impact was
manipulated to produce both injurious and non-injurious conditions so that both
conditions could later be used to develop injury risk functions. Quantitative
comparisons were made between the ATD abdomen force and compression responses
and post-mortem human subject (PMHS) biofidelity corridors obtained from
matched pair PMHS tests under identical loading conditions, using the most
recent version of the NHTSA Biofidelity Ranking System (BRS).
Results
The THOR-05F
exhibited an abdominal force-compression response similar to PMHS, while the
HIII-05F was stiffer in comparison reaching higher peak loads in both belt and
rigid bar loading conditions. Using the updated BRS methodology, the THOR-05F
displayed good biofidelity (BRS score < 2) in compression and force, in both
belt pull and rigid bar impact tests, with an average BRS score of 1.5.
However, the HIII-05F displayed poor biofidelity with a BRS score > 2 in
both loading conditions, as the force deviated from the target response in
addition to not achieving similar compression levels due to abdomen stiffness,
when compared to THOR and PMHS. The average abdomen pressure measured by APTS
sensors ranged from 45 to 130 kPa in THOR-05F, increasing proportionally with
higher stroke and loading rate, while the HIII-5F abdomen does not contain
instrumentation.
Discussion
This study
provides an assessment of abdominal response biofidelity between small female
sized PMHS and 5th Percentile Female ATDs under identical loading conditions.
The abdominal insert in the HIII-05F made of urethane foam covered with vinyl
skin is stiffer when compared with the PMHS corridor. Additionally, the
placement of the abdomen in the pelvis and their interaction may be a
contributing factor to the worse BRS score. The design and construction of the
THOR-05F abdomen allows for a gradual loading similar to the PMHS. Because of
practical challenges in measuring abdomen deflection in a soft ATD abdomen
component, APTS sensors in THOR-05F provide measurements of restraint loading
to the abdomen and assessment of abdomen injury risk. With good BRS scores
observed in the THOR-05F, external measurements such as compression and force
may be correlated with the pressures measured by APTS to develop injury risk
functions.
Conclusion
BRS scores revealed that the THOR-05F
with its advancements proved to have a more PMHS or human like response under
abdominal loading conditions. ATD measurements from the testing in this study
can be used with PMHS injury outcomes to develop injury risk functions for use
with the THOR-05F.
PEER REVIEW Paper No.23-0097-O
Comparative biofidelity
of the Hybrid III and THOR 50th Male ATDs under three restraint conditions
during frontal sled tests
Devon Albert, Stephanie Beeman, Andrew Kemper Virginia Tech, United States
Research
The purpose of
this study was to provide a full-body biofidelity assessment of the Hybrid III
(HIII) and THOR 50th percentile male anthropomorphic test devices (ATDs) during
frontal sled tests, incorporating data from test buck reaction load cells to
provide a novel assessment of external biofidelity. Additionally, the accuracy
of the injury risk curves for each ATD were evaluated against injuries from
post-mortem human surrogates (PMHS).
Methods
Sled tests
designed to simulate a United States New Car Assessment Program (US-NCAP)
frontal test were conducted using the HIII 50th male ATD, THOR-50M ATD, and
eight approximately 50th-percentile male PMHS under three restraint conditions:
knee bolster (KB), KB and steering wheel airbag (SWAB), and knee bolster airbag
(KBAB) and SWAB. Each ATD underwent two tests per restraint condition, while
three PMHS tests were conducted for each restraint condition except for the KB
condition, which only had two PMHS tests. The test buck was designed to match
the interior of a Toyota Camry and included a production seat, steering column
and wheel, SWAB, and three-point belt system with pretensioner and load
limiter. Rigid polyurethane foams were used to simulate the KB and KBAB. The
test buck was instrumented with multi-axis load cells on the steering column,
KB supports, and foot supports. ATD and PMHS reaction force time histories were
quantitatively compared using the ISO/TS-18571 objective rating metric.
Previously published biofidelity analyses of kinematic and chest deflection
data from the same tests were combined with the reaction force analyses to
perform an overall assessment of the comparative biofidelity of each ATD.
Injury risk predictions from existing HIII and proposed THOR injury risk curves
(IRCs) for the US-NCAP were compared to observed injuries.
Results
The reaction load
cell time histories from both ATDs generally had poor similarity to those of
the PMHS, with average ISO scores of 0.54 and 0.49 for the HIII and THOR,
respectively. Across all reaction load cells, the THOR typically produced the
largest forces, while the PMHS produced the smallest. The similarity of the
HIII response to the other surrogates varied with load cell location and
restraint condition. Combining the reaction load ISO scores with previously
published data yielded overall scores of 0.52 and 0.50 for the HIII and THOR,
respectively. Both ATDs were able to predict the observed injuries except for
the HIII chest and THOR neck IRCs, which both under-predicted PMHS injury
outcomes.
Discussion
The reaction
loads indicated that the three surrogates had different interactions with the
steering wheel/column, KB, and foot supports. Despite this, the ATDs had
similar ISO scores for both the external and overall analyses, indicating that
the THOR and HIII had similar biofidelity under these test conditions. However,
this study was limited by a low PMHS sample size.
Conclusion
This study is relevant to the
indicated session because it provides novel biofidelity data on the THOR and
evaluates its most recently proposed IRCs. Results indicated that the THOR and
HIII had similar overall biofidelity and provided mostly accurate injury risk
predictions under test conditions representing the current frontal US-NCAP.
PEER REVIEW Paper No.23-0127-O
Characterizing neck
and spinal response in a booster seated reclined children in frontal impacts
Hans Hauschild,
John Humm Medical College of Wisconsin, United States Valentina Graci, Jalaj Maheshwari Children's Hospital of Philadelphia, United States Research
Belt-positioning
booster seats (BPB), pretensioner and pre-pretensioner (PPT) belts may be
effective in preventing injuries from submarining and head excursion in reclined
children (Hauschild et al 2021, Bohman et al 2021). It is unknown if injuries
at the neck and spine could still occur. This study's goal is to
characterize neck and spine responses to understand spinal injury risk for
reclined children with and without the BPB and the PPT.
Methods
Eleven frontal
impact sled tests were performed (56 kph) with a Large Omni-directional Child
(LODC) dummy on a production vehicle seat. A 3-point simulated
seat-integrated-belt was used with a load-limiter (~4.5 kN). Testing was
conducted with and without the BPB with the seatback at ~25° (nominal), ~45°
and repeated once. One test was conducted at ~60° with the BPB. 100 mm of
belt-slack was removed to simulate PPT in two of four 45° BPB tests and the BPB
60° test. The LODC peak thoracic spine accelerations and angular rotations, and
peak neck and lumbar force/moment loads were compared between conditions.
Results
Neck axial forces
were the highest without the BPB and PPT (25 º noBPB 3.4kN, 45 º noBPB
4.3kN) compared to the BPB conditions (1.9–3.0kN). Neck shear forces were the
highest in the 60º BPB & PPT (-1.9kN) and 45º noBPB (-1.3kN) than all other
BPB conditions (-0.5 to -0.8kN). The highest neck moments were found in the 45º
noBPB (-40.5 N-m), and in the 60º BPB & PPT (-34.2 N-m) conditions compared
to all others (-20.8 to -27.9 N-m.). The 60º BPB and PPT condition demonstrated
thoracic forward rotation similar to the 25º noBPB condition (25º noBPB -24.8
to -35.0 deg, 60 º BPB&PPT -27.5 to -43.2 deg..). Thoracic spine resultant
accelerations (T1, T6, T12) were higher in the 25º and 45º noBPB conditions (53
g to 71g) and in the 60º (T6: 61.8g) compared to all other BPB conditions (48.4
g to 53.1g). The lumbar shear forces and moments were the highest in the
45º noBPB (4.9 kN, -296 N-m) and the 60º BPB & PPT condition (1.7kN, -146
N-m).
Discussion
These findings
show similarities in neck, spine, and lumbar responses between the severe
reclined condition with BPB and PPT countermeasures and the upright and
moderate reclined conditions without the same countermeasures. In severe
reclined condition with BPB, 60º, the LODC exhibited increased peak neck shear
force and lumbar forces and moments similar to the condition with no BPB. The
60º condition showed increased upper thoracic accelerations (T6) compared to
all other BPB conditions These findings suggest that the BPB and PPT may not be
sufficient countermeasures to protect neck and spine in severe reclined child
occupants. Limitations of this study was the investigation of one BPB and
vehicle seat.
Conclusion
Neck and spine injury risks may
increase in severe reclined booster seated children. This study highlights the
need for future restraint developments to protect reclined child
occupants. The LODC is an advanced ATD which was tested in a novel
configuration, reclined, analyzing small occupant responses in a BPB.
Paper No.23-0132-O
A novel Powered
Two-Wheeler rider dummy; specifications and initial testing
Jolyon Carroll Autoliv Research, Sweden Bernard Been Humanetics Europe GmbH, Netherlands Mark Burleigh Humanetics Europe GmbH, United Kingdom
Abstract
Powered Two and Three-Wheelers (PTWs)
are a popular means of transport. Fully electric PTWs can be
operated locally emission-free and, therefore, may support sustainable
transport options. However, in terms of the safety offered to PTW riders
there is still a long way to go compared with other means of transportation. As
such, PTW riders are a vulnerable road user group that stands to benefit from
improved protection. Primarily, this paper provides a detailed description
of the work-in-progressregarding a new crash test dummy, an
ATD (Anthropometric Test Device), intended principally for use in testing
PTWs. The question posed was if a new dummy can facilitate evaluations
of PTW protective systems. The end goal being to promote more widespread
evaluation of protective systems for PTW riders. Importantly, the
development of the PTW riding dummy has paired physical and finite element
models together, from the start, to support both physical and virtual
testing in the future. The ATD development is based on collision (and
injury) statistics of PTWs worldwide, a brief summary of previous research
is presented. As with the development of the Motorcyclist Anthropometric Test
Device (MATD- ISO 13232-3) an updated modification of the Hybrid III pedestrian
is proposed as the principal solution. To this base dummy a small set of
modifications are made to allow simple and yet adequate representation of a PTW
rider. Demonstration of the dummy in use as a PTW rider is provided by
performing full-scale crash tests. Finite element crash simulations are
compared with the physical tests, demonstrating the suitability of using the
finite element dummy model in virtual PTW tests. Details of the PTW dummy
anthropometry are provided as well as the rationale for design updates in
comparison with the MATD. An overview of testing with the dummy is
provided and the results from two full-scale reference tests
(without protective system) are given. Injury predictions based on dummy
measurements are compared with an injury statistics summary. Differences
between the outputs from the physical and finite element models are discussed
in the context of the injury statistics and additional validation of the
tools is suggested. The paper also indicates potential areas where the
dummy could be improved in the future, depending on injury prediction
needs and application, such as to include additional instrumentation in the
abdomen region, for example. Worldwide road traffic statistics suggest that the
number of deaths of PTW riders form an equally large group as deaths among
drivers and passenger of four-wheeled vehicles. In contrast, the former group
has not benefitted from the advancement of protection systems as
implemented in the latter. The availability of new tools in the form of
a hardware ATD and its finite element model representing the PTW rider,
will support development and evaluation of protective systems for PTW
riders.
Paper No.23-0171-O
Pressure-Based abdominal
injury prediction for the THOR-50M
Philippe
Beillas, François Bermond University Gustave Eiffel, France Philippe Petit, Xavier Trosseille LAB PSA Peugeot-Citroën Renault, France Sabine Compigne Toyota Motor Europe NV/SA, Belgium Mitsutoshi Masuda Toyota Motor Corporation, Japan Pascal Baudrit CEESAR, France Mark Burleigh Humanetics Innovative Solutions, Inc., United Kingdom Jerry Wang Humanetics Innovative Solutions, Inc., United States Jocelyn Perisse Transpolis SAS, France Rakshit Ramachandra Transportation Research Center, United States Jason Stammen National Highway Traffic Safety Administration, United
States Olivier Richard FORVIA, France
Abstract
The standard THOR-50M dummy is
equipped with sensors to measure the abdomen deflection and assess the risk of
abdominal injuries. Since 2016, the “ABdominal Injury and SUbmarining
Prediction" (ABISUP) consortium has developed a pressure-measuring abdomen for
the THOR-50M to predict abdominal injuries and submarining as a potential
alternative to the current THOR-50M abdomen design. A new lower abdomen
including Abdominal Pressure Twin Sensor (APTS) was designed and four identical
prototypes were built and shipped to consortium member test houses. Numerous
abdominal belt loadings replicating tests from the literature were carried-out
to check the prototype biofidelity, sensitivity and define a pressure-based
AIS3+ injury risk functions (IRFs). Two compression-based IRFs were defined
using porcine test results from the literature. Compressions were defined as
the ratios between the abdomen deflection and the full abdominal depth, or between
the abdomen deflection and the abdominal depth in front of the spine. The
abdominal depth in front of the spine was used in an attempt to minimize
possible differences between species. It was estimated using simple assumptions
and led to compressions exceeding 100% in a few cases. Then transfer functions
between THOR abdominal compressions and pressures were applied to obtain the
pressure-based IRFs. Twenty-five sled tests were performed to assess the new
abdomen under various restraint conditions and to evaluate the relevance of the
IRFs. The THOR-50M new abdomen showed similar or better biofidelity than the
standard abdomen without modifying the dummy kinematics. The abdomen was
sensitive to loading height and no damage to the APTS was encountered during
tests. Relationships between THOR-50M mean APTS pressure and abdominal
compressions were modelled using a 3rd degree polynomial with 0.98 R². The IRF
with a log-logistic distribution obtained the lowest Akaike Information
Criterion. For the compression based on the full abdomen depth, the AIS3+
injury risks of 25%, 50% and 75% corresponded to APTS pressures of 133, 201 and
304 kPa, respectively. For the compression based on the abdomen in front the
spine, the AIS3+ injury risks of 25%, 50% and 75% corresponded to APTS
pressures of 108, 197 and 361 kPa, respectively. The new abdomen discriminated
between the restraint conditions: lower pressures (between 90 and 190 kPa) were
obtained when the lap belt remained below or on the ASIS and higher pressures (170
to 450 kPa) were obtained when the lap belt loaded the abdomen. Using the IRF,
a risk up to 50% could be obtained without submarining, i.e., with the lap belt
still engaging the ASIS. This is not consistent with a risk expected to be low
for a proper restraint. Possible adjustments are discussed in the paper to
decrease APTS sensitivity when the lap belt is positioned below or on the ASIS.
Paper No.23-0239-O
Construction of a prediction
model for the time series of brain strain of a novel head surrogate using deep learning
Syuntaro Tamai,
Yusuke Miyazaki, Hiroki Yamamoto Tokyo Institute of Technology, Japan Katsushi Yoshii, Ichiro Amamori Joyson Safety Systems Japan K.K., Japan
Abstract
An effective brain injury risk
assessment is required to minimize the risk of brain injury from traffic
accidents. Thus, anthropomorphic test devices (ATD) have been used for overall
vehicle safety evaluation. We developed a novel ATD head that incorporates
detailed intracranial structures with the brain and can measure the relative
displacement between the brain and the skull. However, the strain inside the
deep brain of the head surrogate cannot be measured or estimated. Although we
can simulate the brain strain waveform using the finite element model, the
computational cost is high, and the real-time evaluation of brain strain during
crash tests is difficult. To compute the brain strain response in real-time,
deep learning (DL) methods can be used to predict brain strain behavior.
Therefore, this study aims to propose a method to predict the waveforms of
maximum principal strain in the brain using a DL method called long short-term
memory (LSTM). Reconstructed simulations for impact tests using a finite element
head model were conducted to obtain the principal strain waveforms of the brain
and construct a dataset for machine learning. The impact tests included 125
occipital head impact tests, 7 frontal sled tests, 35 vehicle frontal crash
tests, and 53 American football impact tests, constituting a total of 220 head
impact tests. Furthermore, the LSTM model was trained on triaxial angular
velocity and acceleration waveforms, and the models were constructed to predict
the principal strain waveforms in the cerebellum, brainstem, and right and left
cerebrums. Subsequently, to validate the predictive model of brain strain, CORA
was calculated as an index of the prediction error. The average CORA score
between the brain strain waveforms predicted by LSTM and those of the dataset
was 0.963 for occipital head impact tests, 0.928 for frontal sled tests, 0.898
for vehicle frontal crash tests, and 0.875 for American football tests. The
occipital head impact tests, vehicle frontal crash tests, and frontal sled test
cases were predicted with high accuracy. However, the football impact test
cases were inferior to the other three test cases. The football impact cases
included more multidirectional impact patterns and failed to learn similar
collisions. However, an error in the waveform was observed in the rebound phase
of the head impact in the latter half of the brain strain waveform. Therefore,
the impact test dataset should be expanded, including cases with rebound
behavior of the head, and the set of features that can reflect the rebound
behavior of the head should also be examined further. In conclusion, the
maximum principal strain waveforms of the brain can be rapidly and accurately
predicted from the angular acceleration and angular velocity of the ATD head in
occipital head impact, frontal sled, and vehicle crash test cases using LSTM.
This method enables real-time evaluation of brain strain waveforms during
impact tests.
Paper No.23-0271-O
A simulation study on
the knee-thigh-hip loading of the THOR compared to human body models
Jeremie Peres, Norbert Praxl PDB - Partnership for Dummy Technology and Biomechanics,
Germany
Abstract
The THOR-50M dummy is instrumented
with acetabulum force sensors which is a novelty when compared to previous
dummies like the Hybrid III. It has been proposed to use the acetabulum
resultant force to predict hip injuries. Injury Risk Curves (IRCs) for cadavers
have previously been developed, however it is not clearly established if the
cadaver IRCs can directly be applied to the THOR measurements or if a transfer
function is needed. As femur and acetabulum forces are located on the same load
path, it is also questionable if it is necessary to use two different injury
criteria to predict knee-thigh-hip injuries. To investigate these questions, a
simulation study was performed using a THOR model and two human body models
(HBMs). Load cases included impactor tests derived from published cadaver
testing as well as sled simulations in belted and unbelted configurations with
a validated environment. The knee, femur and acetabulum forces measured in the
different models were compared and the ratios between these forces were also
analyzed. Additionally, based on the measurements from the THOR and HBMs
simulations and published Injury Risk Curves for cadavers and the THOR, the
risks of hip and knee/femur injuries were calculated for each load case.
Results show that the relationship between the forces measured in the THOR
model and in the HBMs could depend on the loading conditions. The forces
measured in the unbelted sled simulations are similar between the three models,
however the acetabulum forces measured for the HBMs in the belted sled
configuration are significantly lower than that of the THOR. For impactor
configurations, the risk calculated at the hip for the THOR overestimates the
likelihood of cadaveric injuries. For sled configurations, no cadaver test result
was available, findings are based on simulations only and comparison with field
data. For all simulations, the risk of hip injury predicted for the THOR was
significantly higher than the risk predicted for both HBMs. The risk of hip
injuries for the THOR was also, for all simulated load cases, higher than the
risk of knee/femur injuries which is contrary to the injury frequencies
observed in the field for belted occupants. Overall, the risks calculated for
the THOR from the acetabulum forces seem overestimated which is likely caused
by the transfer coefficient used to calculate the THOR risks based on the human
IRCs. An adjustment of the transfer coefficient is necessary and might require
a different value for belted and unbelted cases. This study has limitations.
Firstly, the ability of the human body models to measure accurately the
acetabulum force in sled configurations is not established due to the lack of
relevant cadaver data. Secondly, parameter studies and real car simulations
would be needed to generalize the results. To conclude, it is necessary to
define a transfer function for the acetabulum force to predict hip injury risks
properly. This transfer function might be load case dependent.
Paper No.23-0275-O
Development of a
multi-point chest deflection measurement system for the Large Omnidirectional
Child (LODC) anthropomorphic test device (ATD)
Michael Carlson,
Brian Suntay Transportation Research Center Inc, United States Jason Stammen National Highway Traffic Safety Administration (NHTSA),
United States
Abstract
OBJECTIVE The objective of this study
is to evaluate the feasibility and accuracy of a multi-point chest deflection
sensing system installed in the LODC using static, quasi-static, and two
dynamic test conditions. METHOD The multi-point LED chest deflection system was
evaluated at four levels: (1) calibration verification, (2) quasi-static, (3)
dynamic probe impact, and (4) dynamic drop tower in order to demonstrate that
the sensor gave a reasonable and accurate measurement of chest deflection.
RESULTS Individual sensors were found to be quite accurate in static
verification tests, and sensors installed in the LODC ribcage were also
observed to match well with CMM measurements. In dynamic testing with the
full array of sensors installed in the ribcage, LED deflection matched
probe-measured deflection closely. In both frontal and oblique drop tower
tests, individual sensor deflection time histories showed how the full array
could capture full ribcage deformation. CONCLUSIONS A novel non-contact sensor
array to measure LODC chest deformation has been developed. This system
has gone through a battery of both static and dynamic tests thus far to
evaluate the system's performance. Initial results indicate that the
system is promising for monitoring overall chest deformation in the LODC.
Future work will include more dynamic testing to further understand how the
system can describe three-dimensional ribcage deformation.
Paper No.23-0278-O
The influence of the
reproducibility of Anthropomorphic Test Devices on injury risk functions
Norbert Praxl, Christian Gehre PDB - Partnership for Dummy Technology and Biomechanics,
Germany
Abstract
The design of advanced ATD is moving
towards being more human-like and therefore is more complex. More complexity
generally leads to more degrees of freedom, the uncertainty of an ATD as a
measurement tool rises. The uncertainty of a measurement tool is described
by the repeatability and the reproducibility. An ATD alone can only
provide measurements. These measurements do not directly reveal the safety
level of a vehicle in a crash test. By using a mathematical function, a
so-called injury risk function, the ATD measurements can be related to
injury risks. The injury risk is a measure to show how well a vehicle protects
the occupant or vulnerable road user. The influence of a poor
repeatability or reproducibility on the calculation of the injury risk is
obvious. For a given measurement variability it is simple to check the
associated risk variability by putting the values in the relevant injury
risk function. Much less obvious is the effect of poor repeatability and
reproducibility on the injury risk function itself. The injury risk
function for an ATD is typically a combination of PMHS test results and
matched ATD test results. This simple fact reveals that the repeatability
as well as the reproducibility of an ATD can already influence the development
of the injury risk function and not only the calculation of the injury
risk. This study aims to get a basic understanding how the
measurement variability of ATD can influence the resulting injury
risk function. The study uses data from real repeatability and reproducibility
tests with the THOR-50M. For reasons of simplicity the study focuses on
the influence of the reproducibility, that is, a perfect repeatability is
assumed. Two theoretical PMHS data sets are used to study the
reproducibility influence: one with current status data (left and right
censored data) and one with exact data. In addition, two different methods
for the mapping of ATD measurements onto PMHS results in the risk function
development are deployed. This study shows that injury risk curves depend
on ATD reproducibility. Current injury risk function development is
only reliable with a good ATD reproducibility. Data of THOR-50M used
in this study reveals that the current injury risk function
development procedure should consider the reproducibility of the ATD. The
study used only one data set for the reproducibility of the ATD which
limits the generality of the results. In addition, only a theoretical and
simple injury risk function was applied. More complex injury risk
functions with additional co-variants or complex criteria may lead to
diverging results. The general effect that the reproducibility is
influencing the injury risk function is unaffected. As reproducibility cannot
be easily improved because of technical and practical reasons, a methodology
needs to be developed that includes the effects of reproducibility in the
calculation of injury risk curves.
Paper No.23-0288-O
Investigation of the
biofidelity of human body models and ATD models in sled test conditions
Jerry Wang
Autonomous
Vehicle Occupant Safety Consortium AVOS, United States
Abstract
Unique cabin configurations associated
with Automated Driving System (ADS) equipped vehicles offer seating options,
such as recline, not previously available in conventional vehicles. Occupants
seated in a reclined posture may be at an increased risk of submarining. There
is relatively little known about the effectiveness of current restraint systems
to protect reclined occupants as these systems are traditionally optimized for
only upright seated postures. Anthropomorphic Testing Devices (ATDs) with the ability
to differentiate between submarining and non-submarining events are vital for
the development of restraint systems capable of protecting reclined occupants.
This study evaluates the biofidelity of the GHBMC, THUMS, THOR, and THOR-AV
finite element (FE) occupant models against two post-mortem human subject
(PMHS) test series in respect of submarining behavior. The first test series
evaluated upright occupant kinematics in two seat configurations defined in
Uriot et al. 2015: a front-seat configuration expected to prevent submarining
and a rear-seat configuration expected to allow for submarining. The second
tests series evaluated upright and reclined occupant kinematics in a seat
configuration as defined in UMTRI test conditions: both configurations expected
to prevent submarining. Special consideration was given to pelvis kinematics
and submarining response. The four FE occupant models properly differentiated
between non-submarining and submarining responses in each of the evaluated test
conditions. The NHTSA Biofidelity Ranking System (BRS) was used to objectively
evaluate the biofidelity of the models with respect to overall occupant
kinematics, as well as interaction with the restraint system (seat, anti-sub
ramp, and belts). The BioRank score classifies biofidelity as excellent, good,
marginal, or poor. In the first test series, the BRS scores for the interaction
between all FE occupants and the restraint system corresponded to good
biofidelity, except for THOR in the rear-seat submarining configuration
(marginal biofidelity). In the second test series, the BRS scores for the
interaction between the FE occupants and the restraint system corresponded to
marginal biofidelity. With respect to kinematics, the BRS scores for the FE
occupants ranged from good to excellent biofidelity in both test series. For
each FE occupant, an average BRS score was calculated from the four test
conditions. In terms of the interaction between the occupant and the restraint
system, the average BRS scores for the GHBMC, THUMS, and THOR-AV corresponded
to good biofidelity, while the average BRS score for the THOR corresponded to
marginal biofidelity. With respect to kinematics, the GHBMC, THUMS, THOR, and
THOR-AV FE models demonstrated good biofidelity.
Paper No.23-0301-O
Sensitivity of chest deflection
measurements in THOR-5F and Hybrid III small female dummies to different seat
and belt settings
Andre Eggers, Matthias Schießler, Julian Ott, Tobias Langner, Marcus Wisch Federal Highway Research Institute (BASt), Germany
Abstract
In frontal impact test procedures, the
Hybrid III small female dummy is used to increase the protection of small car
occupants. To address the increased thoracic injury risk for elderly occupants
it is planned to introduce more stringent chest assessment criteria. However,
previous studies raised concerns regarding the efficiency of criteria based on
chest deflections measurements in the Hybrid III due to sensitivity of the
measurements to variations in belt routing due to seat and D-ring settings. The
seat in the most forward position and the D-ring in the highest position is
mostly used in assessment tests. These settings result in a belt routing closer
to the neck and reduced mid sternum chest deflection, which is not presentative
of the actual peak deflection and therefore not meaningful to assess the chest
injury risk. The objective of this study was to investigate the effect of chest
deflection sensitivity in the Hybrid III small female dummy in a generic sled
test setup to variations of belt routings representative of contemporary
vehicles. The study was complemented by sled tests with the THOR-5F in the same
configurations to investigate the potential of this dummy as a future
alternative. Furthermore, an analysis of field data was done to evaluate the
preferred seat and D-ring settings of real small car occupants. The results of
the tests with the Hybrid III small female could confirm the findings from
previous studies with shoulder belt routings representing contemporary
vehicles. A routing with the belt closer to the neck showed a reduced sternal
chest deflection in the Hybrid III small female. Corresponding tests with the
THOR-5F showed a similar reduction of peak chest deflection at the maximum
loaded IR-TRACC, but an increase at another location. Therefore, THOR-5F
multi-point criteria might have the potential to address the issue of belt
routing sensitivity. The analysis of field data showed that small
occupants representing the small female dummy in terms of height prefer to set
the D-ring to the lowest position (driver and passenger). For the front seat
passenger, the seat longitudinal and height setting mid/mid is preferred. In
conclusion the recommendations regarding seat and D-ring settings that were
provided in previous studies can be confirmed. To enable an effective
evaluation of chest injury risk with the Hybrid III small female the D‑ring
should be set to the lowest position for the driver as well as for the
passenger side. For the passenger side the seat should be set to the mid/mid-position.
Furthermore, these seat and D-ring settings are the most relevant preferred by
small occupants based on field data. For additional improvement of chest injury
risk assessment considering the specific needs of small female occupant's
further research is recommended related to the THOR-5F and advanced multi-point
chest injury criteria, which might be less sensitive to test parameters and
resulting variation of belt routing. Repeatability and reproducibility of the
chest deflection response of the THOR-5F dummy related the sensitivity of
multi-point defection measurements should be further investigated and improved
if necessary.
Paper No.23-0339-O
THOR-50M fitness assessment
in FMVSS No. 208 unbelted crash tests
James Saunders,
Peter Martin, Dan Parent National Highway Traffic Safety Administration (NHTSA),
United States
Abstract
Research Question/Objective: A
prerequisite for entering a dummy design into CFR Title 49, Part 572 is to
demonstrate that the specifications yield ATD units capable of implementation
in a regulatory environment. Specifications for the THOR-50M have produced
units that are repeatable, reproducible, and durable in many test conditions,
including belted sled tests and qualification testing. Herein, two THOR-50M
units are implemented in a series of unbelted vehicle crash tests run in
accordance with FMVSS No. 208 procedures, and evaluated based on usability,
durability, and the successful collection of sensor data for use in injury risk
prediction. Methods and Data Sources: Two THOR-50M units, both conforming to
NHTSA's 2018 THOR-50M design and qualification specifications, were run in a
series of unbelted crash tests. Nineteen tests were run with four 2020-21
vehicle models: Honda Accord, Mazda CX-5, Chevy Equinox, Ford Escape. Four were
run against a full-frontal barrier and fourteen against an angled barrier in
accordance with FMVSS No. 208 procedures, with the exception of using NHTSA's
THOR 50th Percentile Male Dummy Seating Procedure instead of using FMVSS No.
208 seating. Dummy qualifications were performed periodically throughout the
test series following NHTSA's THOR-50M Qualification Procedures. Results: The
two units held up well to the rigors of the crash tests. Both were fully
instrumented, one of which included an internal DAS system. Sensor anomalies
and failures during tests were traced to cable damage, which was repaired
between tests. The parts and assemblies within both units did not sustain any
damage beyond scuffs and cuts to exterior vinyl components. There were no parts
that needed to be replaced. Dummy qualifications posed no issues. The test lab
was able to maintain a testing schedule typical of other regulatory tests with
other types of dummies. Discussion and Limitations: This test series
demonstrated that the THOR-50M could be implemented in vehicle crash testing
consistent with regulatory compliance testing in that the ATDs showed
sufficient usability and durability. Both units successfully collected sensor
data for use in injury risk prediction. The minor sensor anomalies that did
occur were mostly isolated to the ATD without the internal DAS system. A
limitation of this study was that only four vehicle models were tested, and all
tests were run at a single lab. Conclusions and Relevance to Session Submitted:
In a series of FMVSS No. 208 unbelted frontal rigid barrier crash tests, two
THOR-50M units were implemented and successfully completed the test series.
Scripted procedures for dummy assembly, qualification, and handling were
followed without issue, and the seating procedures resulted in highly uniform
positioning. Sensor anomalies observed over the course of testing were
consistent with those common in dummies already in Part 572. There were no
broken parts or part replacements throughout testing. Based on the experiences
of this testing series, the THOR-50M appears fit for use in standardized
testing.
Paper No.23-0340-O
WorldSID-50M fitness
assessment in FMVSS No. 214 moving deformable barrier and oblique pole crash
tests
Whitney Tatem, Allison Louden National Highway Traffic Safety Administration (NHTSA),
United States
Abstract
A prerequisite for entering an
anthropometric test device (ATD) design into the Code of Federal Regulations
(CFR) Title 49, Part 572 is to demonstrate that the specifications yield units
capable of implementation in a regulatory environment. Specifications for the
WorldSID 50th percentile male (WorldSID-50M) ATD have produced units that are
repeatable, reproducible, and durable in many test conditions. Herein, three
WorldSID-50M units are implemented in a series of vehicle crash tests run in
accordance with the Federal Motor Vehicle Safety Standard (FMVSS) No. 214
procedures, and evaluated based on usability, durability, and the successful
collection of sensor data for use in injury risk prediction. Methods and Data
Sources: The National Highway Traffic Safety Administration (NHTSA)
investigated WorldSID-50M performance in FMVSS No. 214 moving deformable
barrier (MDB) and oblique pole crash tests. Performance metrics assessed
included uniformity in periodic qualification testing during the crash test
series, the durability of the ATD, successful collection of sensor data, and
general usability. All qualification and crash tests were run at one lab with
three WorldSID-50M units. Each ATD was the standard build level F with an
in-dummy data acquisition system (IDDAS) setup (DTS G5 units), a RibEye
Multi-Point Deflection Measurement System, thorax pads, modified shoulder pads,
and a sleeveless suit. Before the test series, each ATD was fully qualified per
NHTSA's WorldSID 50th Percentile Male Qualification Procedures Manual, and
additional qualification tests were conducted throughout the crash series.
Eighteen crash tests with model year 2019 and 2020 vehicles were ultimately
conducted. Results: The three WorldSID-50M units met qualification test requirements
throughout the crash test series with minimal issues. Results were within
performance specifications after tightening loose bolts in the upper and lumbar
spine prior to being used in the crash tests. The WorldSID-50M Dummy Seating
Procedure was followed and resulted in repeatable and reproducible seating
positions. In crash tests, the WorldSID-50M ATDs were durable and successfully
collected sensor data. Apart from a broken ankle in one test, no permanent
damage was seen on any ATD. One pole test resulted in loss of the maximum
thorax rib deflection due to a RibEye LED blockage by another rib. The issue
was resolved by relocating the rib's LEDs. The WorldSID-50M posed no other
difficulties in performing the crash tests. Conclusion and Limitations: This controlled
study of the WorldSID-50M in FMVSS No. 214 testing showed that the ATD is
durable and successfully collects sensor data in both qualification and crash
testing. There were few sensor anomalies throughout the test series, and any
instrumentation issues were quickly resolved. Collectively, this series of
crash tests demonstrates that the design of the WorldSID-50M appears robust and
provides a tool suitable for use in standardized side impact testing. A
limitation of this study is that all tests were conducted at a single lab.
Further, few small, compact, and sub-compact size vehicles were included in
this test series. Additional analysis of data from ongoing crash tests
encompassing a more comprehensive vehicle fleet will yield more wholistic results
assessing the WorldSID-50M.
Wednesday, April 5, 2023, | 08:30-12:30
Chair: Jac Wismans, The Netherlands | Co-Chair: Matteo Rizzi, Sweden
TRACK B | Room: G304
Paper No.23-0015-O
Combining knowledge
and information - Graph-based description of driving scenarios to enable
holistic vehicle safety
Florian Bechler,
Fabian T. Neininger, Stefan Knöß, Bernhard
Grotz ZF Friedrichshafen AG, Germany Jörg Fehr Institute of Engineering and Computational Mechanics,
University of Stuttgart, Germany
Abstract
Currently, vehicle safety is based on
knowledge from injury values, crash pulses, and driving kinematics which leads
to intervention strategies separated into isolated domains of active and
passive safety. In this contribution, it is shown how vehicle safety can be
approached holistically, allowing for human-centered and scenario-based safety
decision-making. For this purpose, information from interior and exterior
vehicle sensors can be linked by a mathematical framework, combining the
knowledge that is already available in the individual domains. A universal
graph representation for driving scenarios is developed to master the
complexity of driving scenarios and allow for an optimized and scenario-based
intervention strategy to minimize occupant injury values. This novel approach
allows for the inclusion of sub-models, expert knowledge, results from previous
simulations, and annotated databases. The resulting graph can be expanded
dynamically for other objects or occupants to reflect all available information
to be considered in case of urgency. As input, interior, and exterior vehicle
sensor data is used. Further information about the driving situation is
subsequently derived from this input and the interaction between those states
is described by the graph dynamically. For example, occupant attentiveness is
derived from measurable eye gaze and eyelid position. From this quantity,
reaction time can be estimated in turn. Combined with exterior information, it
is possible to decide on the intervention strategy like e.g., alerting the
driver. Physical or data-based functional dependencies can be used to represent
such interactions. The uncertainties of the inputs and from the surrogate
models are included in the graph to ensure a reliable decision-making process.
An example of the decision-making process, by modeling the states and actuators
as partially observable Markov decision process (POMDP), shows how to optimize
the airbag efficiency by influencing the head position prior to an impact. This
approach can be extended by additional parameters like driving environment,
occupant occupancy, and seating positions in further iterations to optimize the
intervention strategy for occupants. The proposed framework integrates
scenario-based driving dynamics and existing knowledge from so far separated
safety systems with individual activation logic and trigger points to enable
holistic vehicle safety intervention strategies for the first time. It lays the
foundation to consider new safety hardware, sensor information, and safety
functions through a modular, and holistic approach.
Paper No.23-0034-O
Comparison of injury
severity prediction using selected vehicles from real-world crash data
Susumu Ejima, Tsukasa Goto SUBARU Corporation, Japan Peng Zhang, Kristen Cunningham, Stewart
Wang University of Michigan, United States
Abstract
Advances in automotive telemetry
technology have the potential to predict occupant severity from vehicle
conditions at the time of an accident, and appropriate triage, as well as
transport to a trauma center, can greatly improve subsequent treatment. The
National Automotive Sampling System Crashworthiness Data System (NASS-CDS:
1999-2015) was used to filter for new case selection criteria based on vehicle
type and matched to Subaru vehicle categories. We have proposed four types of
injury severity prediction algorithms that were matched with the categories of
Subaru vehicles. Specifically, 1) ISP model that categorized the principal
direction of force (PDOF) into four impact directions (front, left, rear, and
right) , 2) ISP-R model that considers the effect of the right-front passenger
in addition to the four impact directions, 3) ISP-f1R model that represents
PDOF as a continuous function using periodic basis splines, called functional
data analysis, and 4) ISP-f2R model in which the knot position was modified in
3). In this study, five-fold cross-validation was performed within the training
data (NASS-CDS 1999-2015) to evaluate the performance of these four models. In
addition, external validation was performed using the National Automotive
Sampling System Crash Investigation Sampling System (NASS-CISS: 2017-2019). The
results of the cross-validation showed that the area under the receiver
operating characteristic curve (AUC) was used to evaluate the model
performance, which was 0.854 for the ISP model and 0.862 for the ISP-R model,
indicating that the ISP-R, which considered the influence of the right-front
passenger, was more accurate. The AUC values were 0.847 for the ISP-f1R model
and 0.856 for the ISP-f2R model using a continuous function for the direction
of impact, indicating that the ISP-R model had the highest AUC value among the
models. On the other hand, the validation results with NASS-CISS were 0.817 for
the ISP model and 0.828 for the ISP-R model, and 0.831 for the ISP-f1R model
and 0.828 for the ISP-f2R model, indicating that all models had AUC values
above 0.8. The important factors for the occupant injury prediction algorithm
were delta-V, belt use, age, and crash direction, and the presence of a
right-front occupant was a significant injury risk modifier, especially in side
impact crashes.
Paper No.23-0063-O
Study on the improvement
of pedestrian's visibility by geometric patterns projection lighting
A growing proportion of traffic
accidents with pedestrian fatalities are occurring at night. With conventional
lighting technology, using stronger illumination to increase the visibility of
pedestrians contrarily causes the issue of increasing glare. The present
research therefore devised geometric pattern projection lighting that is aimed
at extending the distance at which drivers can detect pedestrians while at the
same time reducing glare for pedestrians. Test subject verification regarding
visibility of pedestrians by drivers was performed and the effectiveness of the
devised lighting was made clear.
Paper No.23-0067-O
Dynamic testing with
pre-crash activation to design adaptive safety systems
Kai-Ulrich
Machens, Lars Kuebler ZF Automotive Germany GmbH, Germany
Abstract
Pre-crash occupant dynamics change
more and more with the broad usage of advanced driver assistance systems (ADAS)
and automated driving (AD) functions. Occupant interaction with pre-crash
activated seatbelt systems (SBS) represent a challenge and an opportunity at
the same time for providing restraint solutions tailored to the individual
passenger and to the actual driving situation. To fully understand the
dynamics, and to design robust control parameters, the increased complexity can
eventually only be assessed by means of a virtual approach. Consequently, this
requires compulsory realistic advanced physical tests and development targets
to ensure that integrity and functionality of all system components are fully
understood and modeled appropriately. Focusing on the most frequent crash
types: frontal and rear end crashes, allows to use a specially designed,
stripped-down Anthropomorphic Test Device (ATD) to dynamically load the
seatbelt system in a representative way. In addition, a high-precision
surrogate with different selectable upper body moments of inertia, seated on a
generic steel seat with an adjustable backrest is available to extend the range
of the applicable load. In both cases the retaining effect caused by friction
on a real vehicle seat is accounted for by an adjustable viscous damper,
retarding the motion of the lower body. These reduced setups guaranty by design
a direct and accurate positioning of the ATD, minimizing test setup
variability. As a novum, a seamless transition from initial pre-crash dynamics
to the final crash pulse loading can be realized when mounting these ATDs on an
innovative test bench using closed-loop controlled electric linear motors to
accelerate a linear ball bearing guided carbon sled along a 6-meter track for
achieving a maximum in reliability and in repeatability. This physical bench
test represents the foundation not only for demonstrating benefits of pre-crash
activation on seat belt systems but also for validating functional SBS
simulation models, so that numerical simulations become its digital twin.
Reliable digital SBS simulation will be the key to generate more and advanced
seat belt functions. However, the capability to measure efficiently and
accurately via physical tests the performance of these SBS products throughout
the entire range of their functional design space, will promote not only the
product, but further raises the credibility of simulation. A newrating criterion
Characteristic Shoulder Force Level (CFL) evaluating the SBS performance
virtually is proposed, which assess the performance of the SBS intervention up
to force-closure and demonstrates the strength of a hybrid approach. Different
vehicle configurations, crash pulses, load scenarios and SBS activation
strategies can be rated and directly compared to each other. This supports
improved integrated safety systems solutions and allows detailed analyses of
active safety pre-crash interventions as triggered by ADAS or AD. The combined
virtual-physical approach is illustrated via load cases combining braking
intervention with conventional and actively controlled seatbelt systems. The
potential benefit to occupant safety of different combination of braking and
SBS activation is measured and discussed.
PEER REVIEW Paper No.23-0148-O
Multi-Sensor driver
monitoring for drowsiness prediction
Chris Schwarz, John Gaspar University of Iowa, United States Reza Yousefian Aisin Technical Center of America, United States
Research
The questions
addressed in this paper are: 1. Does the addition of heart rate data to a
camera-based DMS improve the performance of a drowsiness model? 2. How far
in advance of lane departures and long eye closures can drowsiness be detected
with a camera-based DMS and with a multi-sensor approach
Methods
Data from 48
participants were collected in the high-fidelity National Advanced Driving
Simulator at the University of Iowa. The simulator consists of a 24-foot
diameter dome enclosing a full-size 2014 Toyota Camry sedan with active
steering and pedal feedback. A 13-degree of freedom motion system provides
participants accurate acceleration, braking, and steering cues. Sixteen
high-definition projectors display seamless imagery on the interior walls of
the dome with a 360-degree horizontal field of view. Drivers completed a
three-hour simulator drive along a nighttime interstate loop. Participants
completed a protocol prior to their overnight driving session such that they
had at least 16 hours continued wakefulness before the drive began. Data were
collected from several sources. Self-reported drowsiness (KSS) was collected
every 10 minutes throughout the drive. Observer ratings of drowsiness (ORD)
were also conducted during the same ten-minute intervals. Driver state
information was collected via two Aisin DMS units integrated into the NADS-1
cab and synchronized with the other data sources. Physiological data was
collected from an Empatica E4 wristband and millimeter wave radar integrated
into the simulator cab. Finally, engineering data from the simulator included
control inputs as well as driving performance measures.
Results
Data from the
vehicle, driver behavior, and driver physiological signals were collected and
analyzed to extract features appropriate for the prediction of drowsiness.
These features were used to train driver drowsiness models. A cross validation
approach was used to test model performance in which participants in the test
set were distinct from participants in the training set. A model trained with
data from a camera-based DMS was compared with one that also includes features
extracted from heart rate data.
Discussion
Common measures
such as PERCLOS and lane departures may come too late to mitigate drowsiness.
If we wish to improve the performance of a drowsiness model, emphasis must be
given to other signals, such as steering activity, blink rates, head pose, and
heart rate. We consider a wearable source for heart rate, but less invasive
measurement methods are also available.
Conclusion
The field of driver monitoring
continues to advance, and while cameras currently dominate the space, other
types of sensors are maturing to the point that they may be included in a
vehicle. Their capabilities to detect drowsiness must be weighed against the
risk of nuisance alerts, false negatives, privacy concerns, and cost. Driver
monitoring falls under the wider field of in-cabin monitoring of driver and
occupants, to which various sensors are being applied. The signals are
applicable to ADAS and ADS applications that warn the driver or adapt
automation capabilities around the driver's state.
Paper No.23-0166-O
Proposed speed limits
for the 2030 motor vehicle
Matteo Rizzi, Rikard Fredriksson Swedish Transport Administration, Sweden Ola Boström Veoneer, Sweden Anders Kullgren Folksam Insurance Company, Sweden Nils Lubbe Autoliv Research, Sweden Johan Strandroth Inc, Sweden Claes Tingvall AFRY, Sweden
Abstract
Vision Zero builds on the aspiration
to keep kinetic energy below human tolerance to prevent fatalities and serious
injuries. In this work, a Swedish expert group within the SAFER arena estimated
the maximum safe speed limits for the 2030 motor vehicle based on the boundary
conditions of vehicles, road infrastructure and human crash tolerance to
achieve close to zero road fatalities and serious injuries. The present work
was based on expert consensus, rather than a retrospective quantitative
analysis of crash data. Different load cases were discussed separately, with
the involvement of a passenger car being the common denominator. The passenger
car and its collision partner were assumed to be of model year 2030, thus
reflecting the base safety level of the Swedish car fleet by approximately
2050. The boundary conditions were set based on pre-crash autonomous braking
ability and the maximum acceptable impact speeds that would result in a very
low risk of death or serious injury among the car occupants and the car's
collision partner. In the case of car to pedestrian impacts, the acceptable
impact speed was set to zero, as any impact with pedestrians can lead to
serious injuries as a result of ground impacts. It was expected that the
responsibility to comply with speed limits will move from the driver to the car
itself, and that travel speeds will be autonomously reduced when low road
friction, sight obstructions, and otherchallenges in the
traffic environment are detected. This function was expected to be
non-overridable. Lateral control was also expected to be further enhanced with
lane support technologies, although it was assumed that it will be still
possible to override such technologies. Over time, increased performance
of vehicle safety technologies will likely be able to prevent an increasingly
large proportion of crashes in all load cases. However, in line with Vision
Zero design principles, human crash tolerance will always be the ultimate
boundary condition to guarantee a safe outcome in a crash. As a result, the
recommended maximum travel speeds in the road transport system containing motor
vehicles only of model year 2030 and beyond are: - 5-7 km/h in pedestrian
priority areas, - 40 km/h in mixed traffic urban areas, if there are no
obstructed sensor sightlines, e.g. due to parked vehicles along the sidewalk, -
50 to 80 km/h on roads without mid- and roadside barriers, - 100+ km/h on roads
with continuous mid- and roadside barriers, - 40 to 60 km/h in intersections,
depending on vehicle mass differences. The results from this work can be used
to inform the development and amendment of transport planning guidelines when
moving away from the economical paradigm into Safe System boundary conditions
in the setting of speed limits.
Paper No.23-0178-O
Safety of electro mobility
- White paper of the FISITA Intelligent Safety Working Group
Klaus Kompass KKo4Safety, Germany Simon Königs, Florian Euhus, Franz Fuchs,
Sascha Zimmermann BMW AG, Germany Rodolfo Schoeneburg RSC Safety Engineering, Germany Rainer Justen Mercedes-Benz AG, Germany Saúl Martin, Genis Mensa Applus IDIADA Group, Spain
Abstract
Battery electric vehicles and plug-in
hybrid electric vehicles experienced significant increases in sales volume,
reaching a worldwide market share of 7% of all newly registered vehicles by the
middle of 2021. One of the central challenges of this paradigm shift lies in
the safety aspects of electric vehicles and their components. For vehicles with
combustion engines, safety aspects have been carefully investigated over
decades, standards, regulations, test requirements and system limitations are
widely established and acknowledged by vehicle manufacturers, suppliers,
government authorities, NGOs, and customers. For electric vehicles, this
process has just started; yet its objective must be to establish a comparable
level of safety taking in consideration the specific needs of those vehicles
and their individual risk assessment. This paper represents a pre-publication
of a White Paper on the Safety of Electromobility, to be published by FISITA,
the Fédération Internationale des Sociétés d´Ingénieurs des Techniques de
l´Automobile. The chapters are designed by dedicated experts from all around
the globe and from a variety of institutions within the engineering society
under the umbrella of FISITAs Intelligent Safety Working Group ISWG. The White
Paper is supposed to be published in autumn, 2023 during the FISITA World
Congress in Barcelona and it summarizes the current state of the art as well as
new research results for safety aspects during the product lifecycle of
electric vehicles and their components. The book will be a precious handbook
for all those who develop, produce, use, repair or work otherwise with vehicles
with high voltage batteries and powertrains. The structure of the White Paper
follows the product lifecycle and covers the safety aspects for all phases in
the following chapters: - EV-components, - Manufacturing, - Use &
Operation, - Repair, Inspection, Maintenance and Service, - Crash protection, -
Thermal events prevention or control, - Rescue, - Cyber Security, -
End-of-Life, Second Life of batteries and Recycling. In separate chapters the
specific Insurance aspects and the use of CAE for safety development,
validation and verification are addressed. Last but not least the White Paper
will give a forecast on future challenges in this area and also provide
references to existing standards and best practices. In this pre-publication
the focus lies on the two chapters “Crash protection" and “Thermal events
prevention or control". Other chapters are planned to be pre-published during
the time frame between today and autumn 2023.
Paper No.23-0234-O
Predictive safety:
Towards holistic top-down systems engineering for pre-crash systems
Philipp
Straßburger, Bernhard Grotz, Stefan Heiss, Jürgen
Metzger ZF Friedrichshafen AG, Germany Bruno Arbter ZF Automotive Germany GmbH, Germany Kilian Hachmann, Nenad Ocelic ZF Mobility Solutions, Germany
Abstract
Since the first equipment of vehicles
with environmental sensors for driver assistance systems more than 20 years
ago, engineers are working on employing this data to improve or enable the
activation of existing or envisioned passive safety systems. This task is
motivated by potential benefits in occupant safety. In particular by an
increased robustness of activation logic or by innovative actuators which
promise to enable more degrees of freedom for new vehicle interior designs and
the positioning of occupants. New regulations for ADAS functionalities lead to
high equipment rates with environmental sensors which can foster the
integration of active and passive safety technologies. Signals with an
appropriate quality can be used smart to improve occupant safety in holistic
safety strategies combining active and passive safety systems still offers big
potentials. In this paper we aim to detail challenges in the multidisciplinary
field of “Pre-Crash", the field of using environmental sensing to improve
occupant safety. This requires considering the whole functional chain: sensor –
perception – prediction - function logic - actuator, and further system
properties like functional safety (including SOTIF topics) or validation
strategies. As an example, throughout this paper, we will use a new
functionality of a reversible pretensioner to reposition a forward leaned
occupant by seatbelt retraction, called Active Occupant Repositioning. By
getting into details, the complexity and mutual influences becomes apparent.
Discontinuous relationships and dependencies on scenario details exist. The
challenge is to divide the problem into manageable tasks. To get a clear
understanding and a basis for communication we classify Pre-Crash systems in
different base architectures and elaborated principal differences to assess the
suitable next step for Pre-Crash system development. Methodologies are
reflected to develop Pre-Crashsystems, and strategies are derived to
adjust the variety of dependent system parameters. Therefore, properties of an
electromechanical actuator are analyzed to come towards a holistic Pre-Crash
system development.
Paper No.23-0244-O
Research on V2X
communication system to reduce pedestrian accidents
Moriya Horiuchi,
Shigeru Inoue, Takahiro Kurehashi, Takashi
Oshima, Yuta Sakagawa Honda R&D Co., Ltd, Japan Yosuke Komiyama, Koichi Serizawa SoftBank Corp., Japan
Abstract
Everyone deserves to feel safe on the
road. The goal is to strive for zero traffic collision fatalities involving
motorcycles and automobiles globally by 2050. Many traffic fatalities are
categorized as vulnerable road users such as pedestrians and cyclists. In
particular, pedestrian fatalities account for the largest portion. Pedestrian
accidents have occurred not only through drivers' errors but through
pedestrians' errors. Thus, in addition to advanced driver-assistance systems,
safety behavior by pedestrians is effective for reducing pedestrian accidents.
Research was therefore conducted on the vehicle-to-everything (V2X)
communication system connecting vehicles and pedestrians to assist both drivers
and pedestrians. The system used 5G standalone mobile communication system and
a cellular-V2X communication system. With an in-vehicle camera, the system
detected a pedestrian walking across a street ahead and in an area that is in a
blind spot for the driver. Then, the total time required for the pedestrian to
receive notification after detection by the in-vehicle camera was estimated.
Also, the reactions of pedestrians were observed, and the time required for
pedestrians to react to notification was measured as well. The result in the
assumed use case was that the system promoted safety behavior by supporting
drivers and pedestrians before collision occurred. However, considering the
reaction time of pedestrians, assisting system users before collision is a
challenge if the time to the collision is extremely short. Therefore, the
system is required to notify the users in plenty of time before the collision.
In order to utilize the system, it is desired to promote widespread adoption by
installing the system on smartphones rather than on dedicated equipment. Also,
the accuracy of location ascertained using smartphone needs to be improved to
establish acceptability. The safe use of communication technologies was
considered as one of the one-step-ahead integrated vehicle safety technologies.
This report details the structure, results, and issues of the V2X communication
system.
Paper No.23-0257-O
Integrated safety for
occupant protection
Simona Roka,Genís Mensa, James Jackson, Cristina Periago, Clara Cabuti, Pablo
Lozano
Alessandro Gravina, Maria De Odriozola, Eduard Romero Applus+ IDIADA, Spain
Abstract
Integrated vehicle safety aims to
connect active and passive safety technologies and has the potential to go far
beyond what each can achieve separately. Improving integrated vehicle safety
has become highly relevant for the development of automated vehicles. The goal
of the ISOP project is to investigate whether applying active safety features
and manoeuvres during the pre-crash phase can negatively influence the
performance of the vehicles' restraint systems in a way that the state-of-the-art
passive safety systems are no longer as effective in preventing fatalities and
avoiding or mitigating injuries in road accidents. A couple of test protocols
have been defined within the project to analyse the effects of pre-crash
manoeuvres on the initial occupant posture. The data from the tests with
volunteers in proving ground performing cut-out manoeuvres have been
collected and have been used as input database for the simulations with the
Human Body Models (HBM). Due to the limitations of the Anthropometric Test
Devices (ATD) in responding to a pre-crash manoeuvre, the effectiveness and
sensibility of the restraint systems has been evaluated by HBM. In contrast to
ATDs, virtual Human Body Models (HBM) represent the anatomic structure of human
beings including bones, flesh, skin, fat, and soft tissue. The high model
detail allows a direct assessment of the injury risk based on the damage
applied to the respective body region (e.g., in form of stress or strain),
assuming a correct damage prediction of the model. Integrated safety enhances
comfort, convenience and can help assist in critical driving situations and in
protecting occupants. However, the state-of-the art restraint systems need to
be evaluated in such novel load cases including the activation of vehicle
active safety systems and the pre-crash manoeuvres. This paper focuses on the
influence of active safety systems towards the protection of vehicle occupants
in the event of a crash that has not been avoided, by developing a combined
series of test protocols, performing volunteer tests and HBM simulations.
Wednesday, April 5, 2023, | 08:30-12:30
Chair: Peter Burns, Canada | Co-Chair: Stacy Balk, United States
TRACK C | Room: G301+G302
Paper No.23-0068-O
System limitation
experiences by Swedish drivers using ACC and LKA
Maria
Klingegård Folksam Insurance Company, Sweden Annika Larsson Arriver, Sweden
Abstract
For many ADAS to reach its full safety
potential they need to be activated and used by its drivers. There are thus
several known (technical) limitations that could, as indicated by research,
potentially affect the perception and use of the ADAS. This paper explores
limitations as experienced by users for the lateral assistance systems Adaptive
Cruise control (ACC) and Lane Keep assist (LKA). The paper partly reports on a
larger online survey launched (n=1822) in 2021 aimed to explore self-reported
use and non-use of six different ADAS among Swedish drivers using a 5-point
Likert scale. Descriptive statistics including frequencies and a calculated
summative level of agreement % is presented together with 95% confidence
levels. Included in the analysis is those respondents reporting using ACC
(n=1002), and/or LKA (n=461). Presented are limitations as experienced,
frequency of use/non-use, and perceived driving experience. Results show
that ACC is being activated (always/often) to a greater extent (84%) than LKA
(57%), and for LKA it varies by frequency of driving. The majority of the
participants had experienced more than one limitation (ACC:72%, LKA:68%), on a
regular basis, which results in deactivation of the system. Only about 20 %
(ACC:20%, LKA 18%) had never experienced that they could not use the ADAS.
Those who do not experience any limitations, never experience the need to
deactivate the ADAS to a greater extent- ACC: (38% vs 22%) and LKA (48% vs.
23%). Statistical significant tests relived a significant difference between
LKA and ACC, in which LKA was affected to a greater extent for bad weather
(48%), glare (48%), position in lane (27%), complex traffic (27%) while ACC was
affected to a greater extent by dirty sensors (45%), complex traffic (43%), weather
(31%). ACC also contribute (significantly) to a higher degree to a
positive driving experience than LKA, likewise are more trusted and easier to
use. This study highlights some of the reasons why ADAS are regularly turned
off, diminishing their safety potential. Technological developments, together
with standardization and infrastructure adaptation, may be required for ADAS to
fully realize their safety potential.
Paper No.23-0263-O
Key human factors
development principles for DMS enhanced collision avoidance system development
Mikael Ljung
Aust Volvo Cars, Sweden
Abstract
Driver monitoring systems (DMS) can
enhance Collision Avoidance Systems (CAS) in numerous ways, for instance by
adjusting warnings or interventions when drivers are inattentive or in other
ways disengaged or impaired. However, the driver interaction principles applied
when using DMS to enhance CAS must be based on State-of-the-Art Human Factors
research and have a clear focus on understanding driver needs and in what way
assistance should be provided to be appreciated by the driver. Otherwise, one
risks implementing interactions that either do not make sense or are perceived
as disturbing, both of which degrade the CAS's safety potential. Some of these
interaction principles may not be fully intuitive unless your background is in
behavioral psychology. For example, it may be surprising that DMS is best used
to delay certain collision avoidance warnings rather than supply them earlier.
It may also not be fully intuitive that DMS is best used for detection of
generic degradations in the behavioral patterns that define normal driving
rather than for diagnosis of specific impaired states. To use a CAS properly,
you need to interact with it regularly to learn what its outputs mean. However,
current accident and mileage statistics suggest that driving conflicts where a
CAS could save you from an unrecoverable error that otherwise would have
resulted in a high severity crash are rare; maybe as infrequent as once in a
decade or lifetime depending on how one does the calculation. From a design
perspective, CAS are therefore best approached as lifetime driving companions.
You may only need them once, but they still need to be interacted with
regularly to work as intended. Hence, the conversation between driver and CAS
should adhere to the same principles as applied between humans. For example, if
your colleague is busy, you only interrupt for good reason, and if you
interrupt regularly, both of you must agree its relevant and the message must
be clear (though not necessarily loud) so the other person quickly can decide
whether to interrupt the current task. In this paper, first a general framework
and corresponding design approach for CAS is formulated based on accident
statistics, driving mileage and CAS interaction frequency analysis. Next, three
specific development principles for DMS enhanced CAS are described to
illustrate what the outcome is when the framework and design approach are
applied in practice. These include how DMS enhancement can be used to avoid
“cry wolf" effects in CAS interactions, how DMS enhancement can be used to get
CAS timing right for both distracted and aware drivers and finally, how DMS
offers a more efficient way than specific state diagnosis when tackling driver
impairment. By explicitly describing these fundamental Human Factors
development principles for DMS enhanced CAS to the traffic safety engineering
community, one may avoid unnecessary development pitfalls that could counteract
DMS enhanced CAS deployment.
Paper No.23-0315-O
Methodology and test
protocol development for driver engagement during assisted driving
Cristina
Periago, James Jackson, Clara
Cabutí, Francesco Deiana, Adria Roig Applus+ IDIADA, Spain
Abstract
One of the great challenges around the
advent of driver assistance systems is to ensure that drivers understand the
true capability of technology, such that they can behave accordingly for safe
vehicle operation. This understanding can be influenced by a range of factors including
vehicle instructions, user interface and warnings, and system control behavior.
Validation accounting for these important aspects is therefore central to
understanding and comparing safety performance for real world use for overall
system design implementations. This paper presents a test methodology specified
for implementation on an automotive proving ground facility capturing pre-use
information, and driver-vehicle interaction during assisted driving regarding
user interface and system control behavior. Data collection was defined around
the quantification of driver engagement with the driving task using subjective
measures to assess progressive effects of system use and objective metrics
considering driver behavior and capability to respond to an emergency scenario.
In a pilot assessment, a between-subjects test was conducted using two vehicles
with differing assisted driving concepts. A sample of naïve drivers (n=39) was
recruited and, following a customer focused description of system functionality,
was instructed to drive on a test track in continuous highway driving scenario
with longitudinal and lateral driver assistance features active. Subsequently,
a critical 'cut-out' event was presented requiring a driver response to avoid
an in-lane obstacle. Results indicate variability in how drivers interact with
the system during 'normal driving' with subjective measures demonstrating
differences in metrics associated with engagement. Likewise, objective measures
for driver reaction to the critical event signify differing levels of driver
vigilance associated with perceived functionality of individual systems.
Outcomes from this experimental test mark a step in the development of test
methods for global assistance system assessment and provide a platform for
further progression and refinement of tests. This has implications system
design verification with highly replicability whilst accounting for use by
representative drivers, alongside possible applications in consumer and
regulatory testing with representative drivers.
Paper No.23-0162-O
Development of a
performance-based procedure for SAE Level 2 driver engagement assessments
André Wiggerich German Federal Highway Research Institute
(BASt), Germany
Abstract
Adapting the performance and design of
Advanced Driver Assistance Systems (ADAS) and Automated Driving Systems (ADS)
to human capabilities and safety needs is an important requirement for a safe
market introduction of new technologies in this field. A specific challenge for
SAE Level 2 systems is the engagement of the driver in the driving task. A high
level of driver engagement is necessary to ensure that drivers are able to
fulfill their role and responsibility to monitor the system performance and to
intervene in system limit situations. However, effectiveness of current driver
monitoring technologies to ensure driver engagement are limited with broadly
diversified performance parameters. Therefore, the aim of the current research
was to develop and validate a standardized procedure for performance-based
assessments of driver engagement of Level 2 systems with a direct link to
safety by focusing on controllability in accident-prone system limit
situations. In total, 39 drivers without prior experience in continuously
assisting systems participated in the evaluation study on a test track. To
assess the validity of the procedure and the standardized test scenario, half
of the participants experienced a Level 2 system (Tesla Autopilot) while the
other half drove the same vehicle (Tesla Model 3) conventionally (fully
manual). The participant's task was to constantly follow a lead vehicle, driven
by a second experimenter, on a round course for approx. 30 minutes. At the end
of the test drive an accident-prone system limit situation without a prior
system-initiated warning was triggered: The lead vehicle performed a cut-out
maneuver revealing a stationary crash target in front of the participant.
Without driver intervention, the Level 2 system was not able to avoid a
collision. Therefore, the participant was required to react by braking and/or
steering. Results indicate that the test scenario is controllable by
conventional drivers. No driver of this group caused a collision or had a
Time-To-Collision minimum below 1 second. However, drivers of the Level 2
system specifically used in the study had difficulties in controlling the
system limit situation and intervening adequately to avoid a collision with the
stationary target. 15% of these drivers collided with the target and approx.
50% had a Time-To-Collision minimum below 1 second. Furthermore, the median
Time-To-Collision minimum of the Level 2 drivers was approx. 1.5 seconds lower
compared to conventional drivers. Concluding, it can be stated that the test
scenario is in general controllable by conventional drivers but, due to a lack
of driver engagement of the Level 2 system tested in the study, participants of
this group had problems in intervening adequately to the system limit. In
summary, the developed procedure is a pragmatic, reliable and valid way to
assess driver engagement independently and in a design-neutral way by focusing
on safety critical interaction behavior in system limit situations.
Paper No.23-0295-O
Evaluation of
simulated Level 2 hands-free driving in real traffic – an innovative method for
an early SOTIF Human Factors assessment of ADAS under realistic driving
conditions
Manuela Witt, Florian Raisch, Martin Götze, Burak Gülsen BMW AG, Germany
Abstract
Objective: Recent activities in the
development of assisted and automated driving involve vivid discussions about
the necessity to evaluate the interaction between the driver and the system,
especially while using high performant SAE Level 2 functions (see SAE, 2016).
The assessment of safety in use of these systems is fundamental and includes
several methods that can be applied to evaluate the controllability of the
systems, e.g., simulation, driving simulator studies, and realistic driving
studies on test tracks or in real traffic. In early development stages, it is
barely possible to assess the functions in real traffic. However, some research
questions need to be addressed early and can be answered the most appropriate
by studies in real traffic. Therefore, a method to simulate new SAE Level 2 and
even Level 3 systems in test vehicles has been developed. Method: A new method
to assess driver behavior and controllability of system limits in real traffic
is presented: By using assisted driving functions of series vehicles, higher
assisted functions can be simulated in the user interface and additional
functional features can be implemented, such as automated lane changes that can
be triggered by a trained safety driver sitting on the passenger seat. Thereby,
it is possible to assess fundamental Human Factors aspects, such as mode
confusion, overreliance or overtrust, under highly realistic study conditions
oreven
assess controllability of lateral steering errors in real traffic. A realistic
driving study to assess controllability of such system limits while driving SAE
Level 2 hands-free is presented. Results: Simulating new SAE Level 2 functions
by using special test vehicles and trained safety drivers enables researchers
to evaluate the driver's interaction with these functions under controlled and
very realistic conditions. The results of such studies can help to identify
risks and, thereby, define appropriate measures to address and minimize them.
Moreover, hypotheses about driver behavior can be tested and validated to
support a safety-oriented development process. The results of the presented
study on controllability of sudden steering errors show that attentive drivers
are able to control system-detected as well as system-undetected lane drifts
while driving SAE Level 2 hands-free. Differences in reaction times were
significantly correlated with if the steering error occurred and an urgent
warning was triggered or if the lane drift was undetected by the system and no
warning was issued. Conclusion: Evaluating driver behavior in real traffic
while using SAE Level 2 systems is necessary to assess safety in use of these
functions before introducing them into the market. Simulating new systems in
series vehicles helps getting important insights into driver behavior while
using such functions. System limits to be expected can be presented and
controllability of the resulting situations can be assessed as well as driver
reactions in terms of reaction times and quality of intervention.
Paper No.23-0296-O
Preventing driver misuse
with proactive ADAS
Robert Fuchs, Yuuta Sakai, Tsutomu Tamura JTEKT Corporation, Japan
Abstract
As a consequence of the fast adoption
of driving automation systems, most vehicles available on the market are the
result of a robot-centered development approach. A few decades ago, the major
challenges faced by the engineers were to implement sensors and control
capability enabling the vehicle to follow and remain within a lane. For safety
and to ensure compliance with the evolving regulations, driver monitoring
systems (hands-on detection, head, and gaze cameras) and override or takeover
strategies completed the necessary equipment. The human driver has been
considered afterward the development of the robot-like vehicle. Focusing on
lateral control, the majority of level-2 vehicles use an override strategy,
which segregates manual from automated steering operation. Sometimes, this
causes confusion resulting in distrust and ultimately misuse. Consequently, the
level of acceptance of ADAS functions remains under the expectation. Active
interaction with the automation is proposed to leverage driver engagement,
which is considered as one of the key indicators for assessing safety of ADAS
functions. The concept of haptic shared control of the steering enables manual
intervention over the automation without deactivation. Systematic and
consistent reconsideration of level-2 ADAS functions becomes possible when
haptic interaction is exploited. Two proactive ADAS functions: active lane
centering assistance and assisted lane change are proposed to enhance driver
engagement while reducing the risk of misuse. Furthermore, it raises the
question of the relevance of the driver monitoring system.
Paper No.23-0307-O
Evaluation of
interfaces for augmenting a driver's ability to anticipate front risks in real
traffic
Matti Krüger Honda Research Institute Europe GmbH, Germany Vanessa Krüger, Taisuke Mukai Honda R&D Europe GmbH, Germany
Abstract
Effective alerts are often subject to
a tradeoff between relevance and utility. While it is easier to acknowledge the
relevance of a warning about an imminent hazard than a more distant threat, the
possibilities to act appropriately in response to notifications decrease with
threat distance. To benefit from the advantages of early notifications without
creating annoyance and ignorance, we introduce a variety of Human-Machine
Interfaces that provide driver assistance by scaling stimulus saliency in
accordance with the urgency of a front risk in traffic. Further, we report an
initial investigation of the influence of the HMIs on measures of front
collision risk and subjective driver experience after prolonged use in real
traffic. Three functional HMI prototypes were implemented in a roadworthy
vehicle, equipped with additional hardware for front risk detection, stimulus
presentation, assistance control, and data logging. Participants with advanced
driving practice received these vehicles for 12 days in total for personal
daily use, consisting of 3 guaranteed days of use for one of each HMI prototype
and 3 days of driving without any added front risk notifications. Besides
continuous logging of driving data and risk estimates, subjective data were
acquired in the form of logbook entries and interviews. Measures of driving
safety were high across all conditions, indicating no occurrence of critical
situations. No HMI specific safety effects on top of high baseline levels were
observed. Subjective ratings show a trend for an increasing perceivability and
usefulness of a sound-based HMI with extended system exposure. Participant feedback
suggests that no such adaptations may have been necessary for the remaining
vision-based HMIs because intuition could be gained quickly. Future HMI
iterations should refine the balance between salience and subtlety to better
align with actual safety levels while future investigations might benefit from
longer individual exposures or an experimental control of safety levels.
Paper No.23-0137-O
Drivers' response to automation-initiated
disengagement in real-world hands-free driving
Pnina Gershon, Bruce Mehler, Bryan Reimer MIT, United States
Abstract
Driving automation features in the
form of advanced driver assistance systems (ADAS) that can control the
longitudinal and lateral vehicle kinematics on sustained bases (SAE Level2) are
becoming increasingly available in consumer vehicles, making the study of
drivers' behavioral adaptation and the impacts of automation central to driving
safety. This study used real-world data to assess drivers' responses to
automation-initiated disengagements by quantifying changes in drivers'
moment-to-moment visual attention and vehicle control behaviors. Fourteen
drivers (36% female) drove for one-month each a Cadillac CT6 equipped with a
data acquisition system that recorded driving kinematics, miles driven,
automation use, GPS, and video of the driver and driving environment.
Cadillac's Super-Cruise (SC) is one of the most advanced, commercially
available partial automation systems that, when engaged, enables hands-free
driving while directly monitoring the driver's head orientation. A total of 265
SC initiated disengagement events were identified (mean=18.9; SD=16.5 per
driver) across 5,514 miles driven with SC. In general, SC initiated
disengagements were associated with substantial changes in glance distribution.
Immediately after disengagement, the proportion of glances to the Road
decreased from 83% to 68% and at the same time the proportion of glances to the
Instrument Cluster increased substantially, from 8% to 27%. The period
following SC initiated disengagement was also characterized by a 44% increase
in the overall number of transitions between glance areas (from 845 transitions
before to 1218 after the disengagement across events). The most dominant visual
attention patterns after SC disengagements were Road to Instrument Cluster (57%
increase) and Instrument Cluster to Road (222% increase). Linear quantile
mixed-effects models were used to estimate glance duration before and after
disengagements. Findings indicate that on-road glance duration following SC
disengagement decreased significantly and was 4.86sec shorter in the 85th
quantile (Q15Before=0.5, CI=[0-2.24], Q15After=0.43, CI=[0-2.11], p=.04;
Q50Before=2.02, CI=[0.8-3.24], Q50After=1.45, CI=[1.02-1.88], p=ns;
Q85Before=6.63, CI=[2.06-11.2] to Q85After=1.77, CI=[0-3.67], p<.001).
Analysis of driver hands on-wheel behavior indicate that drivers adopted SC's
hands-free feature to a substantial degree, taking both hands off the steering
wheel more than 75% of the time SC was engaged. Takeover duration when driving
hands-free was significantly longer (2.4sec) compared to driving with at least
one hand on the steering wheel (1.8sec). In conclusion, concerns over the
phenomenon of driver out-of-the-loop, coupled with known limitations of partial
automation systems, have led research to focus on driver response to automation-initiated
disengagement and the ability to regain manual control. We find that real-world
automation-initiated disengagements trigger substantial changes in driver
glance behavior including shorter on-road glances and frequent transitions
between the Road and the Instrument Cluster glance areas. This behavior pattern
likely represents drivers' searching for information related to the
disengagement or the automation state and may be shaped by the automation
design. Higher levels of automation may introduce more substantial changes in
visual and vehicle control behaviors during automation-initiated disengagements.
This data provides useful information to designers charged with developing
assistive and automated systems and empowers regulators and safety advocates
with insights needed to better guide appropriate utilization of ADAS
technologies.
Paper No.23-0135-O
Measuring the transition
window in conditional automation
John
Gaspar, Omar Ahmad, Chris Schwarz University of Iowa, United States Thomas Fincannon National Highway Traffic Safety
Administration (NHTSA), United States
Abstract
Conditional (SAE driving automation
level 3) automation is projected to see broader deployment by several
manufacturers in multiple countries. L3 Automated Driving Systems (ADS) target
performing the entire dynamic driving task (DDT) within an operational design
domain (ODD), allowing the user to disengage while the system is active, but
expect that the driver remains “takeover ready." In practice, one expectation
of conditional automation is that the system will issue a request to intervene
(RTI) prior to exiting its ODD, with a “sufficient" time window for the user to
reengage in manual driving. To date, research has yet to provide an
understanding of what a sufficient transition window will be in the context of
near-production systems, specifically in those designed to operate in low-speed
traffic jams. This study used an adaptive approach to adjust the timing of the
request to intervene during transitions of control in a high-fidelity driving
simulator. The transition adjusted from transition event to event based on
whether participants were able to successfully take control in the previous
event. Success was defined in reference to a baseline group who drove with
expectations of being fully engaged in driving (i.e., SAE driving automation
level 2). The results show that most participants were able to successfully
make transitions with transition windows in the range of 4.5 to 5 seconds.
However, some participants took several seconds longer to make successful
transitions and for the subset of participants looking away from the forward
road at the onset of the RTI, transition windows in the range of 7-7.5 seconds
led to more successful transitions. This study provides a starting point for
developing an objective definition of a “sufficient" transition window in the
context of low-speed conditional Automated Driving Systems.
PEER REVIEW Paper No.23-0087-O
Silent failure
detection in partial automation as a function of visual attentiveness
John
Gaspar, Chris Schwarz, Cher
Carney University of Iowa, United States Pujitha Gunaratne Toyota Collaborative Safety Research Center, United
States
Research
The objective of
this study is to determine how driver visual attentiveness contributes to the
likelihood of silent failure detection.
Methods
Data from 24
participants were collected in the high-fidelity National Advanced Driving
Simulator. Participants completed a study drive with a partially automated (SAE
L2) driving system. The driving task transitioned between periods of free flow
traffic (55mph) and lower-speed traffic jams (22mph). Throughout the drive,
participants were incentivized to engage with a realistic email task while also
being instructed that they were expected to monitor the driving scene and state
of the automation. At the end of the study drive, participants encountered a
“silent failure" event. This event consisted of a deceased deer covering half
of the participant's lane of travel. The deer was revealed by a lead vehicle at
four seconds time-to-collision. Critically, the event was “silent" in that the
automated system did not detect or respond to the low-profile object. Driving
simulator, eye tracking, and video coding data were used to provide response
measures and metrics of driver attentiveness.
Results
Thirteen of the
twenty-four participants in the study completely failed to detect the deer. Of
the 11 participants who detected the deer, 7 were able to successfully respond
to avoid the revealed object. Visual attention preceding the silent failure was
quantified through coding of glance location. Of particular interest was the
frequency, timing, and duration of glances to the forward roadway leading up to
the reveal event. The data show significant variability with respect to how
drivers deploy attention in the presence of an engaging non-driving task while
partial automation is active. These patterns of visual attention were
predictive of likelihood of responding to the silent failure.
Discussion
Many studies have
examined driver response to takeover requests at different levels of
automation. Silent (i.e., unalerted) failures, however, pose a particular
challenge for partial automation, where drivers are expected to monitor the
road and automation. The results of this study show that silent failures are
unlikely to be detected when drivers are engaged in a non-driving task.
Furthermore, these results speak to individual differences with respect to the
deployment of visual attention between a non-driving task and the driving
scene. It is important to note that this study included a single silent failure
and may not reflect the actual frequency of such failures in real driving.
Conclusion
This study helps map the relationship
between patterns of visual attentiveness and detection of silent failure events
in partial automation. Silent failures are one of the most difficult challenges
in partial automation and therefore it is important to understand how human
limitations will impact the design of automated systems. The results of this
study can be used to develop models of driver attention in automation under
variable conditions and help define thresholds for driver monitoring
technologies.
PEER REVIEW Paper No.23-0069-O
Driver eye glance
behavior and performance with camera-based visibility systems versus mirrors
Elizabeth
Mazzae U.S. Department of Transportation, National
Highway Traffic Safety Administration, United States Kelly Satterfield, G.H. Scott Baldwin, Isabella
Skuce, Adam Andrella Transportation Research Center Inc, United States
Research
Drivers' ability
to extract visual information efficiently from mirrors or camera-based
visibility systems will impact their performance carrying out driving maneuvers
(e.g., lane changes). The objective of the research was to compare
drivers' eye glance behavior and driving performance with mirrors versus
camera-based visibility systems (i.e., CMS, or camera monitor system) to
identify any differences and consider the possible impact of differences on
safety.
Methods
The paper will
describe two complementary studies. The first was a test track study comparing
drivers' eye glance and lane change behavior when driving a vehicle equipped
with outside mirrors versus a prototype CMS in daylight and darkness.
Participants' opinions about usability and comfort in using mirrors versus the
tested CMS were obtained using a questionnaire. The second study was conducted
in a stationary vehicle and used a modified Posner Cueing Task to elicit shifts
in gaze between the forward view and the mirror or CMS display. Speed and
accuracy of response were examined. The second study had two parts: one
comparing outside mirrors to a CMS and another comparing an inside mirror to a
camera-based electronic alternative.
Results
Test track study
results showed that with the tested CMS, participants took longer to pass a
slower moving vehicle and maintained a greater resultant distance from the
passed vehicle. Additionally, participants fixated more on the CMS displays
under certain conditions compared to the outside rearview mirrors. Participants
subjectively rated outside rearview mirrors as having better ease of use,
comfortability, and visibility than the tested CMS. When asked to choose which
rear visibility technology they would prefer to use in everyday driving, most
participants indicated a preference for the outside rearview mirrors over only
the CMS or having both systems. Results for the stationary assessment of
drivers' accuracy and speed of responding to a visual stimulus presented in
inside or outside mirrors or CMS display are pending. Hypotheses predict that
responses will be faster and more accurate for mirror conditions, indicating
drivers have more difficulty focusing on images in the CMS electronic displays
than they do focusing on images in mirrors.
Discussion
Aside from
driver's subjective preferences regarding technology, it is believed that some
percentage of drivers may have difficulty effectively using images produced by
camera-based visibility systems due to issues with visual accommodation,
age-relation vision issues, or eyewear (e.g., bifocals). Limitations of this
research include, for the test track study, the low number of participants (9)
for one test vehicle condition and the use of a prototype CMS, for which
results may not be generalizable to production systems.
Conclusion
Test track study participants' longer
time to pass a slower moving vehicle with the tested CMS may indicate
difficulty in focusing on the electronic CMS image. Hypotheses for the
stationary testing suggest that drivers' accuracy and speed of responding to a
visual stimulus visible in inside or outside mirrors or CMS display will be
different for mirror conditions than for CMS. This paper is applicable to
the noted session because it relates to driver interaction with new
camera-based visibility system technology.
Paper No.23-0195-O
Research on attention
keeping technology to reduce careless driving accidents
We explore how a driver's attention
changes when exposed to auditory and haptic stimuli. In many cases, accidents
caused by internal factors, typified by drowsy driving and careless driving,
result in serious accidents. Therefore, it is important to keep the driver from
losing attention. Thus far, manufacturers have built systems to promote arousal
by engaging visual and auditory alarms when the driver loses attention.
However, in such cases the driver has already lost attention when the alarm is
engaged. Depending on driving circumstances, it is impossible to immediately
stop the vehicle or take a break, and in some cases the driver has no choice
but to continue driving despite their decreased level of attention. This paper
focuses on auditory and vibratory stimuli as realistic methods of stimulus that
can actually be supplied to the driver by products and establishes stimulus
methods with indications of a relationship to autonomic nerve activity. The
paper also evaluates the effectiveness of these methods in preventing loss of
attention, by supplying the established stimulus under conditions in which drivers
have begun to lose attention in the past. The stimulus methods are as follows.
(1) Music: Comparatively high-tempo music at around 100–130 beats per minute
(bpm). (2) Music with amplified bass: The same music described in (1), but with
its bass range amplified. (3) Music with vibration: Music with superimposed
vibrations in sync with the bpm of the music described in (1), from a sound
source in the seatback peaking at 60 Hz. Test subjects were put into a driving
simulator that employed these stimuli and asked to follow the vehicle in front
of them for 30 minutes. Each of the 11 test subjects repeated four trials,
including trials with no stimuli. Several indicators were collected during
these trials. For driving behavior, the indicator was Time-to-Collision (TTC),
for subjective sleepiness it was time-dependent change in the Karolinska
Sleepiness Scale (KSS), and for a parasympathetic indicator it was Standard
Deviation of NN intervals (SDNN), which is the standard deviation of the R-R
Interval. The eight test subjects for which data was properly collected tended
to exhibit higher minimum TTC during the trails with stimulus than those
without. This increased greatly (p <0.01) when bass amplification and
superimposed vibrations were used. It was found that subjective sleepiness,
which was the time for which test subjects were aware of being sleepy,
decreased by 58% with the music stimulus (1), 86% with the music with amplified
bass stimulus (2), and 77% for the music with vibration stimulus (3), compared
to with no stimulus. Moreover, the SDNN trend revealed parasympathetic
acceleration when there was no stimulus, but this was suppressed for both (1)
music only and (3) music with vibration. For (2) music with amplified bass in
particular, it remained in the same state from the beginning of the test.
Applying the knowledge above to inhibit loss of concentration before it occurs
can be expected to help reduce traffic accidents associated with internal
factors such as drowsy driving and careless driving.
Paper No.23-0216-O
Benefits of tactile
warning and alerting of the driver through an active seat belt system
Frank Laakmann,
Martin Seyffert, Thomas Herpich ZF Friedrichshafen AG, Germany Lotte Saupp, Stefan Ladwig Institute for Automotive Engineering (ika), RWTH Aachen
University, Germany Mirko Kugelmeier fka GmbH, Germany Mark Vollrath Technische Universität Braunschweig, Germany
Abstract
Research Question/Objective:
Strengthening human ability to perform the driving task in emergency situations
is a key ambition of vehicle design. This work aims to further improve driver
reaction time by utilizing the tactile sensory channel in multi-modal warning
concepts. A specific emphasis of the work is the evaluation of unique
characteristics of tactile warning through an active seat belt system in
contrast to other modalities. Methods and Data Sources: Two complementary user
studies were conducted by two independent research facilities with two dynamic
driving simulators. With 87 participants in total there was the aim for
statistical relevance of the measurements. The setup included alternative
driver warning concepts for both drivers, during manual and assisted driving,
and drivers engaged in another task during conditional driving automation. The
tactile warning by the active seat belt system consisted of a series of retract
pulses on low force levels. The assumption is that drivers will benefit from a
high exclusivity of the modality in comparison to a tactile seat, steering wheel,
or pedal. Results: In a first setup (manual driving, undistracted), the
replacement of the acoustic/auditory warning by a tactile warning, when
combined with a visual signal, resulted in an improvement of reaction time of
250 milliseconds for brake initiation. In a second setup (AD SAE Level 3) the
driver took over vehicle control 1.0 second earlier with a combination of
auditory, tactile, and visual warning compared to a warning without
vibrotactile alerting. Discussion: Until now, only a few studies existed aimed
to evaluate a tactile warning provided by a seat belt system. The work may
support, within the limitations of these studies, the initial assumption that a
seat belt system providing vibrotactile stimuli to the torso – specifically
chest and shoulder – shows some unique benefits. The exclusivity of the sensory
channel and a low interference with other signals in the vehicle lead to high
degrees of detectability, discriminability, and intelligibility. Limitations
and outlook: Is the use of a tactile warning always positive, or what are
effects of training or habituation? A differentiated semantic design of such
tactile stimuli, the incorporation in escalating and multi-modal warning
concepts, and the combination with a holistic occupant monitoring are seen as
levers for improvement and subjects of further investigations. Conclusion: This
research has found that tactile warning of the driver, through an active seat belt
system, can contribute significantly to improved warning effectiveness and can
help to improve the driver's ability to react in vehicles equipped with
Advanced Driver Assistance Systems (ADAS) and Automated Driving Systems (ADS).
Functions like take-over request (TOR) or forward collision warning (FCW) may
benefit by more robust alerting of the driver as part of the emergency warning
procedure.
Paper No.23-0232-O
A human machine
interface suggested from neuroscientific analysis of human factor
Shin'ichi Murakami,
Koji Dan, Toshiaki Seo, Takaya Yamazaki, Miki
Cho, Minoru Higuchi Honda R&D Co., Ltd., Japan Daisuke Matsuyoshi, Ryota Kanai ARAYA Inc., Japan Yasunori Aizawa, Makiko Yamada National Institutes for Quantum Science and Technology,
Japan
Abstract
Honda aims for zero traffic collision
fatalities involving Honda motorcycles and automobiles globally by 2050. To
realize a zero traffic-incident society, we need to minimize human driver
errors. Improper processing of information should trigger human errors during
driving, however, despite its importance for our society, neural mechanisms
during driving that can lead to catastrophic traffic consequences remain
unclear. To clarify these, we have researched the relationships among drivers'
manipulation, gaze, and brain activation. In particular, we have focused on the
human eye gaze because it is not only a passive input organ, but also reflects
dynamic information processing in the brain. To investigate the human brain
mechanisms involved in safe and secure driving, we scanned the human brain
using functional magnetic resonance imaging(fMRI) while driving in an
MRI-compatible driving-simulator. We introduce one of the experiments showing
differential brain activation between safe drivers and control drivers
manipulating a vehicle in ordinary traffic conditions. In this experiment,
participants were healthy adults, and they manipulated the driving-simulator in
the MRI scanner, while their driving manipulation and gaze were monitored. The
participants encountered risk factors in the driving scenarios. We extracted
the difference in the brain activation at gazing some risks between the safe
drivers and control drivers, then the differences in brain activity between
safe drivers and others were found in the precuneus, V1, and SMA. Then we
constructed a human-machine interface (HMI) that aimed to complement and
enhance the cognitive processing which is necessary for safe driving. To verify
the efficacy of our HMI, we conducted experiments by using driving-simulator
composed of the front part of N-BOX(Honda) and 5 displays (65 inches), the
original system. As a result, the suggested HMI could have effect on early
noticing and avoiding high-risk object. It is possible, therefore, that general
drivers began to drive more safely with a safe driver-inspired information
processing assistance system. Our findings will help elaborate the
specification of devices for ADAS and ADS.
Paper No.23-0293-O
Driver Alcohol
Detection System for Safety (DADSS) – A vehicle safety technology approach to
reducing alcohol-impaired driving – A status update
Michael
Willis Jr., Abdulatif Zaouk, Remi Fournier KEA Technologies Inc, United States Robert Strassburger Automotive Coalition for Traffic Safety, Inc., United States Eric Traube National Highway Traffic Safety Administration (NHTSA),
United States Susan Ferguson Susan Ferguson, United States
Abstract
Alcohol-impaired driving continues to
take a significant toll among road users both in the United States and around
the world. In 2021, an estimated 42,915 people died in motor vehicle traffic
crashes, a 10.5% increase from 2020. The projection is the highest number of
fatalities since 2005 and the largest annual percentage increase in the
Fatality Analysis Reporting System's (FARS) history. In 2020, in the
U.S. alone, motor vehicle fatalities from crashes involving alcohol totaled
11,654, a 14% increase over 2019, which accounts for approximately 30% of all
traffic fatalities in the US for the year. To better address this ongoing
problem, in 2008 the National Highway Traffic Safety Administration (NHTSA) and
the Automotive Coalition for Traffic Safety (ACTS) formed a cooperative
research partnership to explore the feasibility, the potential benefits of, and
the public policy challenges associated with the widespread use of non-invasive
technologies to prevent alcohol-impaired driving. This partnership, known as
the Driver Alcohol Detection System for Safety (DADSS) Program has made
great strides forward in the development of in-vehicle technologies that will
measure blood or breath alcohol and may prevent alcohol-impaired drivers from
driving their vehicles. Exploratory research in earlier phases of the program
established the feasibility of two sensor approaches, breath- and touch-based,
for in-vehicle use. The sensors have since been refined, in terms of both
hardware and software, as the program strives to meet the performance
specifications required for unobtrusive and reliable alcohol measurement.
In late 2021 the program announced that the first zero-tolerance breath alcohol
sensor product equipped with new alcohol detection technology will be available
for open licensing in commercial vehicles. “Open licensing" means that the
technology, which measures a driver's breath alcohol concentration, will be
made available to any product integrator for preparation into fleet vehicles.
The breath sensor is designed for fleet operators implementing a zero-tolerance
alcohol policy for their drivers, staff, or employees. It requires a directed
puff of breath and provides a “pass/fail" reading of the driver's breath
alcohol concentration. Currently the DADSS program is focused on transitioning
the latest generations of consumer breath and touch sensors from research to
product development. Numerous parallel research programs
continue including sensor development, development of calibration
processes, materials and instrumentation that will verify the technologies
are meeting these elevated performance specifications, human subject testing in
conditions that replicate those likely to be experienced in the real world, and
real-world field trials in diverse settings. The goal for DADSS
technologies is commercialization. This paper will outline the
technological approaches and the status of the various DADSS research programs.
Wednesday, April 5, 2023, | 2:00-6:00
Chair: Andre Seeck, Germany | Co-Chair: Michiel van Ratingen, Belgium
TRACK B | Room: G304
PEER REVIEW Paper No.23-0085-O
Increasing seat belt
use in the United States by promoting and requiring more effective seat belt
reminder systems
David Kidd Insurance Institute for Highway Safety,
United States
Research
In the US, 90
percent of front row occupants use a seat belt, but nearly half in fatal
crashes are unbelted. Federal Motor Vehicle Safety Standard (FMVSS) 208
requires every passenger vehicle to provide a continuous or intermittent
auditory signal lasting 4-8 seconds and a visual display lasting 60 seconds
when the driver is unbelted at ignition. Unfortunately, this requirement does
not result in seat belt reminder systems that increase seat belt use.
Methods
This paper
summarizes the state-of-the-art in using vehicle technology to increase seat
belt use, the pertinence of safety standards worldwide, and the development of
a consumer information program that addresses regulatory deficiencies in the
U.S.
Results
Most people
routinely buckle up. Those that do not typically forget, are going on a short
trip, or find belts uncomfortable. Visual and audible seat belt reminders can
cue forgetful occupants to buckle up and motivate more stubborn occupants to do
the same. For several decades, manufacturers have equipped U.S. vehicles with
“enhanced" seat belt reminders that exceed FMVSS 208. Enhanced reminders
increase belt use by 6 percentage points relative to ones that only meet the
requirement, but not all enhanced reminders are identical. More persistent
reminders, like those required in Europe, with a continuous audible signal
lasting at least 100 seconds are the most effective and increase belt use
30%-34% among drivers who do not routinely buckle up. Seat belt interlocks are
an alternative to reminders but have a politically charged past. In 1973, the
National Highway Traffic Safety Administration (NHTSA) required interlocks in
vehicles without passive restraints that prevented the vehicle from starting
when the driver was unbelted. The resulting public outcry resulted in a law
prohibiting NHTSA from requiring or allowing seat belt interlocks and
restricted NHTSA from requiring more stringent reminders. The restrictions were
relaxed nearly 40 years later, but sentiment towards interlocks remains
negative. Opinions towards front and rear reminders are far more favorable, and,
critically, interlocks that prevent shifting into gear or that restrict speed
are no more effective for increasing seat belt use than persistent audible
signals lasting at least 100 seconds. FMVSS 208 only requires reminders for the
driver but belt use in rear seating positions is lower. Rear occupants also
commonly forget to buckle up which provides an opportunity for reminders to
increase rear belt use. Existing European and Japanese requirements for rear
seat belt reminders provide a model for similar requirements in the U.S.
Discussion
Based on existing
research and safety standards worldwide, the Insurance Institute for Highway
Safety developed a rating program to promote effective seat belt reminders for
every seating position in new vehicles sold in the U.S. The highest ratings are
given to vehicles with persistent audible reminders lasting at least 90 seconds
for each front row seating position, and that give information about second row
seat belt use at ignition and when use changes.
Conclusion
The program provides a path for
strengthening safety standards in the U.S., harmonizing U.S. standards with
those abroad, and saving 1,500 lives each year.
Paper No.23-0147-O
Assessment and comparison
of advanced driver assistance system test procedures
Luke
Neurauter, Dave Kizyma, Andrew Krum Virginia Tech Transportation Institute, United States Aaron Greenwood National Highway Traffic Safety
Administration (NHTSA), United States
Research
Vehicle safety
testing programs such as the National Highway Traffic Safety Administration's
(NHTSA's) New Car Assessment Program (NCAP), the Insurance Institute for
Highway Safety (IIHS), Euro NCAP, and other regional NCAPs, have been
established to provide consumers with vehicle safety information to help them
make informed purchasing decisions. These testing programs have historically
focused on the crashworthiness safety performance of a vehicle across a variety
of collision types (e.g., frontal and side impacts) and assigning safety
ratings to vehicles based on how well vehicles perform in a series of crash
tests. In the early part of the last decade, however, rapid development of
advanced driver assistance systems (ADAS) and increased capabilities thereof,
have spurred continued integration of crash avoidance safety technologies into
the established rating systems across the global testing organizations. These
crash avoidance systems increase road safety by helping the driver to either
avoid crashes altogether, or, in the event of a crash, mitigate the severity of
the crash. Although ADAS technologies are now a part of each testing program's
vehicle assessments, the technologies evaluated, and the pace of incorporating
such tests into overall safety rating measures varies across testing
organizations. Objectives consisted of gathering and reviewing test procedures,
quantifying differences between available and upcoming test procedures, and
summarizing differences among ADAS test procedures across testing
organizations.
Methods
Currently, there
is no globally accepted single set of test procedures for crash avoidance
systems, which means that each testing program's assessment and rating methods
may differ. The analysis presented offers a thorough review of varying testing
and rating approaches and provides insights on the rationale and justifications
for differences based on a literature review and expert stakeholder input.
Results
The review of
available test information for all test organizations revealed that a large
number of crash avoidance technologies are currently included in vehicle
assessments, and revisions and additions are planned for upcoming years.
Discussion
General
differences were observed between testing organizations and were
consistent across protocols available from each testing organization—most
notably, the scoring assessments and how those were communicated. Importantly,
differences pertaining to test scenarios, parameters, number of trials, and
test equipment received most of the attention due to their direct impact on the
vehicle's overall assessment.
Conclusion
Ultimately, the analysis conducted
throughout this project provided a comprehensive snapshot of the current crash
avoidance test procedure landscape across vehicle assessment programs.
Differences are highlighted to emphasize the varying approaches employed.
Paper No.23-0173-O
Development of rear
seat occupant safety metrics for the moderate overlap frontal evaluation test
Marcy Edwards, Sushant Jagtap, Jessica Jermakian Insurance Institute for Highway Safety, United States
Abstract Rear
seat safety advancements have lagged those in the front. To address this gap,
this research aimed to develop assessment metrics to evaluate the relative
protection provided by rear seat restraint systems across a series of vehicle
crash tests. Thirty-two full-scale vehicle crash tests were conducted with a
Hybrid III 5th percentile female dummy seated in the left rear seating position
in a 64.4 km/h, 40% offset deformable barrier test. Vehicles varied in size,
class, and presence of belt pretensioners and load limiters. Dummy injury
metrics for the head, neck, thorax, and femur were evaluated along with
occupant kinematic metrics including head excursion and submarining. Of the 32
tests, 18 also included a pressure sensor on the rear occupant's thorax to
locate the dynamic shoulder belt position. Shoulder belt tensions ranged from
3.4 to 8.3 kN, and higher shoulder belt tensions were generally associated with
higher head and neck injury values, but sternum deflection did not show a
similar relationship. High (> 40 mm) and low (~20 mm) sternum deflections
were observed for vehicles with and without pretensioners and load limiters and
for a wide range of belt tensions. Higher dynamic belt positions were
correlated with lower chest deflections and compensating for the effect of belt
position aligned sternum deflections with expectations based on shoulder belt
tensions. Head contact only occurred in one vehicle, but head excursion
boundaries in the absence of impact remain important to ensure that restraint
systems limit excursion and the risk of head injury for higher severities or
larger occupants. The dummy showed propensity for submarining, an important
risk factor for abdominal injuries. Femur axial forces were low for all
vehicles, even in cases where the knees contacted the front seatback.
Assessment metrics were developed to evaluate the relative protection of rear
occupants across a range of vehicles. A novel dummy-based metric, called the
Chest Index, was developed that allows the comparison of chest protection
across vehicles with a range of dynamic belt fit.
Paper No.23-0190-O
The effectiveness of
Seat Belt Reminder(SBR)s by analyzing the result of the pilot project of an
interurban bus with SBR
Jinseop Park, Seung Hoon Lee, Joon-Ho Jun Korea Automobile Testing & Research Institute
(KATRI), Republic of Korea
Abstract
It is a widely accepted fact that seat
belts have been saving numerous lives in traffic crashes. However, if the
effectual means are not used, discussing the effects is meaningless. This is
why many countries make seat belt reminders (hereafter SBR) mandatory or
introduce SBR assessment in their New Car Assessment Programs (hereafter NCAP).
Although a SBR is a good solution for raising the seat belt wearing rate, the
opinion on how many seat-belt non-users can be restrained by SBRs is arguable.
This paper discussed the effect of SBR systems through the pilot project of an
SBR-equipped interurban bus. Korea Automobile Testing and Research Institute
(hereafter KATRI) developed the customized SBR system for an interurban bus,
which is actually being operated between two cities in Korea. The system
consisted of a visual warning device, an occupancy detection sensor, and a
buckle-up detection sensor (buckle-switch) on each passenger seat. There was a
monitoring display system on the bus driver seat, so which seats are unfastened
can be monitored and recorded. In order to figure out how many passengers wore
seat belts; both the observational investigation and recorded data analysis
were conducted. The results were compared with the one of buses without the SBR
system. According to the observed result, the wearing rate of seat belts in a
bus without the SBR was 9.6% and the rate in a bus with SBR was 59.0%. To
figure out how effective the SBR system is, the recorded log data was also
analyzed. The overall average seat belt use rate of the SBR-installed bus was
calculated to be approximately 55.82%. There was a difference between both
results of the observational investigation and log data analysis, but it is
clear that the SBR system noticeably increased seat belt wearing rate. The SBR
system applied to this pilot project did not include an audible warning. This
means that the system reminded passengers of not wearing seat belts only by a
warning light when they did not buckle up. Therefore, the effectiveness of SBR
in this paper is only limited to the type of SBR with a visual warning. SBR
systems do influence the seat belt use rate. This paper showed that the SBR
with occupant detection and visual warning could increase the rate by about 40
to 50%, compared to the case without the SBR. The current regulation does not
require mandatory SBR for all seats and most NCAPs do not equally assess SBR in
front and rear seats. Mandatory SBRs in the rear seats of M2 and M3 and the
introduction of more advanced SBR assessment for NCAPs need to be studied and
discussed.
Paper No.23-0191-O
Virtual simulation-based
assessment of ADAS in consumer tests by openPASS
Felix
Fahrenkrog, Manel Hammouda, Florian Fischer, Ludwig
Maier BMW AG, Germany
Abstract
Test of consumer protection
organizations like the New Car Assessment Programmes (NCAPs) play an important
role in the overall safety of modern vehicles. Being focused on passive safety
over the past decades, the importance of active safety systems has grown in
recent times more and more. To assess the performance of active safety systems,
standardized test scenarios which are supposed to represent real world
accidents are used today. The constantly increasing requirements and the goal
of ensuring the robustness of those active safety systems lead to a vast amount
of test scenarios. This trend is accompanied with the aim of testing more
complex scenarios. In the future, it will hardly be possible to cover this
amount of test by track tests alone. Therefore, new virtual methods to support
the assessments are required. This paper aims to discuss the question: What are
the requirements for these virtual methods to be implemented on manufacture and
consumer rating organization side? To discuss the posed question, a two-stage
process is foreseen. In the first step, an exemplary virtual assessment of
safety oriented ADAS is conducted. For this purpose, consumer rating test
scenarios are set-up within the simulation software openPASS. After the
implementation, an assessment for one vehicle and one active safety function is
conducted in this virtual environment. Finally, the difference between
simulation and real vehicle tests is analyzed. In the second step, the
learnings and findings from this study will be used to discuss the requirements
for future virtual assessments. The demonstration study in openPASS will cover
only an exemplary set of test scenarios. Furthermore, the study will only be
conducted for one vehicle. The generalization of the study's findings needs to
be investigated further.
Paper No.23-0208-O
User-centered
communication of automated driving to promote road safety
Elisabeth Shi German Federal Highway Research Instutute
(BASt), Germany
Abstract
Both research literature and fatal
accidents on roads worldwide question whether users and manufacturers of a
driver assistance system indeed share the same understanding of the intended
system use, and the extent of assistance provided. Traditionally and until
today, irrespective of whether assistance systems (SAE Level 1 and 2) are
active or not (SAE Level 0), the person on the driver's seat is in charge
of the driving task, and any driver assistance systems only support the driver,
but do not relieve him or her. In the near future, further driving automation
systems of SAE Levels 3 will become available. A first Level 3
function on a series production vehicle has been granted type approval in
Germany in December 2021. With increasing driving automation, the
driving-related role changes for the person seated on the driver's seat. For
instance, when Level 3 driving automation is active, the role changes from
the “driver" to the “fallback-ready user" with fundamentally different responsibilities.
Considering that misconceptions about the driver role already exist today, it
is to be expected that with increasing diversity of the role, misconceptions
will likewise grow. Researchers point out non-expert users' difficulties in
understanding the provided extent of assistance or automation and highlight
negative examples of misleading communication. Raising awareness to these
problems may constitute a first step towards finding a solution. Social
psychological research on social influence, however, shows that social norms
strongly influence our behavior. Considering these findings on the influence of
social norms, this article reminds how a focus on (a) some drivers' system
misuse and (b) negative examples of some automakers' misleading communication
may just promote these among the respective target groups ((a)system users, (b)
automakers). Instead, this article provides a concept for user-centered
communication that focusses on how to use respective systems, rather than on
what not to do. In this context, the user-centered communication concept by the
German Federal Highway Research Institute (BASt) is presented. The
communication concept provides the central information that users of different
driving automation systems need to know. The target group of such communication
are non-expert users and the communication's aim is to convey the relevant
information about their responsibilities when using different driving
automation systems. The communication concept can serve as a basis to develop
specific communication campaigns or strategies in different contexts, such as
driver education and training, tutoring, or marketing. The concept has been
adopted by the Round Table for Automated Driving of the German Federal Ministry
for Digital and Transport and is currently applied in the context of consumer
protection by EuroNCAP and other national consumer protection associations.
Paper No.23-0209-O
Euro NCAP's first step
toward rider safety with new car-to-motorcyclist scenarios
Pierre-Marie
Damon, Aurélien Garcia UTAC, France Adriano Palao The European New Car Assessment Programme (Euro NCAP),
Belgium
Abstract
Embedded collision avoidance systems
such as Autonomous Emergency Braking Systems, Forward Collision Warnings or
Emergency Lane Keeping Systems have largely contributed to reducing the number
of car collisions over the past decade. Although those systems have
demonstrated ever-increasing performance in case of imminent risk of collision
against pedestrian, bicyclist, or car in recent years, most of them were not
capable of intervening in the case of a motorcyclist. Since motorcycle crashes
remain a major concern across Europe and for most of them are the result of
collisions between cars and motorcycles, those systems were identified as
relevant technologies to address this issue. In that context, UTAC led the MUSE
European project between 2017 and 2019 with the ambition to promote
motorcyclist safety through car consumer information programs such as Euro
NCAP. As this topic was well identified in the Euro NCAP 2020-2025 roadmap, the
organization showed interest in the outcomes of the project and their
integration into the new generation of car active safety testing protocols.
This paper presents the background established during the MUSE project, its
outcomes, and their integration into the so-called Euro NCAP safety rating, as
well as the outlook for motorcyclist safety as part of Euro NCAP Vision 2030.
Paper No.23-0235-O
Selection of test
parameters for a consumer information crash test program to evaluate the safety
of rear-seat occupants
Sushant
Jagtap, Marcy Edwards, Jessica
Jermakian Insurance Institute for Highway Safety, United States
Abstract
Regulatory and consumer information
frontal crash testing programs in the United States have historically focused
on the front seat occupants. The result has been significant safety
improvements for people in those seating positions but not necessarily for
rear-seat occupants. The objective of this research was to select a crash configuration,
anthropomorphic test device (ATD), and seat position for a crash test program
to evaluate and incentivize rear-seat safety improvements in frontal crashes.
Twelve full-scale vehicle crash tests were conducted with two different crash
configurations (25% and 40% offset deformable barrier tests at 64.4 km/h) and
four different ATDs (H3-50th male, H3-5th female, H3 10-year-old, and THOR 5th
female) seated in the left and right rear outboard positions. Vehicles with
rear-seat pretensioners and load limiters were compared with their previous
generation counterparts without advanced belt technology in test conditions
matched by crash configuration, ATD, and seating position. The H3-5th female
dummy represents an average stature for rear-seat passengers in frontal
crashes, and the study showed that a 40% offset deformable barrier with an
H3-5th female dummy positioned in the second-row seat behind the driver best
reproduces common injury mechanisms documented in the field data and best
discriminates between restraint system performance. The 40% offset deformable
barrier test was more severe than the 25% offset test, which resulted in higher
head and neck injury values and higher incidence of submarining in the 40%
offset test. For all ATDs except the H3-50M, the left rear seating position was
more challenging than the right, producing higher head and neck injury numbers,
similar or higher chest injury numbers, and increased incidence of submarining.
All ATDs tested showed reduced injury risks for vehicles equipped with
pretensioners and load limiters. However, the ATDs also showed potential
tradeoffs for occupants of different sizes. The smallest dummy (H3 10-year-old)
had the highest incidence of submarining, while the largest dummy (H3-50th
male) had the largest headexcursions and the only cases in which
the dummy's head made contact with the interior of the vehicle. The shoulder
belt remained on the ATD shoulder in all cases except in one instance with a
THOR 5th female ATD seated in the right seating position.
Paper No.23-0264-O
Developing a consumer
safety rating for heavy goods vehicles
Matthew Avery, Colin Grover Thatcham Research, United Kingdom Iain Knight Apollo Vehicle Safety Limited, United Kingdom
Abstract
In Europe, Heavy Goods Vehicles
(GVW>3,500kg, aka trucks), represent around 1.5% of registered vehicles, and
about 6% of traffic (vehicle km) but are involved in collisions resulting in
nearly 15% of road fatalities. Goods transport is an essential fact of modern
life, delivering most of our food and luxuries. This link to standard of living
will tend to drive increasing truck use and Vision Zero clearly will not be achieved
unless action is taken to improve HGV safety. Size and mass bring significant difficulty,
but the challenges are not only technical. Freight transport runs on slim
margins. Payload capacity, vehicle uptime, fuel and maintenance bills can all
outweigh the latest safety innovation when it comes to vehicle specifications.
How can we ensure a rating has influence when the relationship between Euro
NCAP and the vehicle buyer will be business to business and not business to
consumer? How can we create the market for safety that manufacturers need to
allow innovation? One make and model can cover variants from an 18 tonne rigid
for urban distribution, through off-road construction vehicles and on to 60
tonne multi-trailer combinations for long haul. How can the rating be applied
in a meaningful yet economic way? This paper summarises several years of work
to find the answer to these questions, that has involved analysing collision
data, investigating the availability, effectiveness and operational constraints
of different technical safety measures that could be promoted, and engaging
extensively with road owners, safety organisations, the freight operations industry,
and the vehicle industry. New and quite stringent regulation of HGV safety is
imminent in Europe, and this has also been a major consideration. Does this
already solve the problems? Is there a need to go further? These questions are
considered via a case study of measures intended to protect vulnerable road
users The end result is what we believe to be a globally unique application of
the consumer rating approach to solve a complex and multi-faceted problem.
Paper No.23-0284-O
Euro NCAP virtual testing
- Crashworthiness
Corina Klug, Martin
Schachner TU Graz, Austria James Ellway, Michiel van Ratingen The European New Car Assessment Programme (Euro NCAP),
Belgium
Andre Eggers German Federal Highway Research Instutute (BASt), Germany Jakub Galazka Toyota Motor Europe, Belgium Simon Gargallo ZF Friedrichshafen AG, Germany Cristian Jimenez Applus+ IDIADA, Spain Jessica Kirch Honda R&D Europe GmbH, Germany Ines Levallois Faurecia, France Uwe Lobenwein Mercedes-Benz AG, Germany Norman Meissner BMW AG, Germany Victor Pardede Hyundai Motor Group, Germany Bengt Pipkorn Autoliv, Sweden
Abstract
The European New Car Assessment
Programme (Euro NCAP) began using numerical simulations in its vehicle ratings
in 2009. Virtual testing with human body models was first used in the
assessment of vehicles equipped with deployable pedestrian protection systems.
In 2019, Euro NCAP created the Virtual Testing Crashworthiness (VTC) working
group. This working group is supported by Euro NCAP, Euro NCAP's members along
with industry representatives from both the European Automobile Manufacturers
Association (ACEA) and the European Association of Automotive Suppliers
(CLEPA). The far side occupant assessment was selected as the first load case
for this work. The objective of this paper is to introduce the procedures
defined by the Virtual Testing Crashworthiness working group and present the
results generated within the two pilot test series. In addition to the
standard load cases defined in the current far-side assessment protocols,
robustness load cases were defined with varying impact angles and seat heights.
Simulations of the specified load cases were performed by the car manufacturers
with their internally developed and validated vehicle models. Two series of
physical far side sled tests were performed in accordance with the Euro NCAP
Far side occupant sled test procedure with the corresponding vehicles. These
test series were used to evaluate the validity of the vehicle models and the
capabilities of the simulation models to predict the trends observed within the
tests. Processes and acceptance criteria were established to ensure that the
simulation models are as representative as possible of their physical
counterparts while protecting the intellectual property of the car
manufacturers and suppliers. The validated vehicle models are used in a series
of robustness simulations. The physical sled test results from the pilot phase
showed reasonable test scatters, even when using two different WorldSID
dummies, and were shown to be a suitable test result to be used for validation
of the vehicle models. The developed procedure was applicable within the pilot
tests. The ISO Scores, used as objective validation metrics, were comparable
between standard and the new robustness load cases, indicating that the
procedure and the model used were robust. Further room for improvement of the
assessment procedure was identified, specifically regarding the acceptance
criteria of signals with low amplitudes. The current study outlines the
procedures for introducing virtual testing of occupant safety into consumer
information. When viewing vehicle safety ratings from a consumer perspective,
it is acknowledged that computer simulations cannot completely replace physical
testing. However, a combination of physical and virtual testing offers a
powerful and flexible assessment of vehicle safety. The robustness load cases
will be assessed in the future based on the virtual tests only and complement
the existing far-side occupant assessment in the final vehicle rating.
Paper No.23-0286-O
Euro NCAP's current
and future in-cabin monitoring systems assessment
Adriano Palao The European New Car Assessment Programme
(Euro NCAP), Netherlands Rikard Friedriksson The Swedish Transport Administration, Sweden Mike Lenné Seeing Machines, Australia
Abstract
Informed by international research and
crash data, Euro NCAP has developed a Test and Assessment protocol to measure
the performance of direct Driver State Monitoring (DSM) systems, which is
implemented from January 2023 as part of the Safety Assist – Safe Driving
protocol of the star rating. This protocol was developed in collaboration with
experts from several OEMs and Tier 1 and 2 suppliers, and it is aimed at
promoting standard fitment of driver monitoring systems that effectively detect
impaired and distracted driving, eventually triggering the appropriate vehicle
response strategies to warn driver and/or mitigate risks. Getting the full
score in the Occupant State Monitoring (OSM) area will only be possible with
direct monitoring systems. The protocol describes the DSM system requirements
across three areas: Sensing (system performance degradation in the presence of
several noise variables such as stature, light, facial features); Driver State
(system capability to effectively deem the driver as distracted, fatigued, or
unresponsive); and Vehicle Response (vehicle deploying timely and appropriate
response strategies, eventually avoiding the accident, or mitigating its
severity). This paper discusses the rationale behind the assessment methodology
and the resulting protocol, and how Euro NCAP envisions DSM as an effective
tool to reducing/mitigating a wide variety of traffic accidents. Over the
course of 2023 test campaign, Euro NCAP will collect extensive insights from
both a practical implementation and technology capability perspective, opening
the door for on-going improvements and further requirements. In the coming
decade, Euro NCAP expects Driver (or Occupant) State Monitoring systems to
tackle areas such as driver engagement, intoxication, optimized passive
restraints, child presence detection, optimized passive safety, as well as
enhancing the performance and intuitiveness of other ADAS by making them work
in synchrony with the driver behavior – eventually increasing driver
acceptance. Lastly, the 2023 requirements for direct DSM are based on
parameters related to eye gaze and head posture – these are subject to be
expanded, allowing for new methods and systems to be used in future.
Paper No.23-0298-O
Developing a consumer
safety rating for vans
Colin Grover, Matthew Avery Thatcham Research, United Kingdom Iain Knight Apollo Vehicle Safety Limited, United Kingdom
Abstract
Home delivery is one of many trends
driving a strong increase in the use of light commercial vehicles (≤
3,500kg GVW, aka vans). In Europe, vans have for many years been subject to
less stringent safety regulations than passenger cars and had fewer safety systems
fitted. The research objective was, therefore, to assess the safety risks posed
by the increasing use of vans and to develop a programme of consumer testing to
promote relevant risk mitigations. The work involved a wide range of Euro NCAP
Member organisations under the umbrella of the Commercial Vehicle Working
Group, chaired by Thatcham Research, and subsequent evolution under its own
unique working group chaired by CSI. The work programme undertaken by the group
included: Collision data analysis Market research to assess ADAS fitment Full
scale collision test Track testing of ADAS solutions Across 5 Euro NCAP member
countries vans were involved in around 8% of road fatalities. The types of
collisions they were involved in, the causes and consequences were similar to
those of passenger cars. The most common collision opponent was other passenger
cars, but the fatalities were not evenly distributed between each vehicle. In
collisions involving vans, a larger proportion of the total fatalities occurred
in the car than in the van. A full-scale vehicle to vehicle crash test was
undertaken between a van and a 5-star car. The van exhibited limitations in
terms of both self-protection and compatibility. Both van occupants showed a
high risk of injury to the chest, knee, femur, and pelvis. The good design of
the passenger car helped limit the consequences for its occupants, but they
still showed significantly higher risk of injury than in the equivalent barrier
test. Market research showed that the availability of ADAS was low, almost
always optional and, even when available, was poorly understood by dealers
making it hard to actually get hold of vehicles. Tests of the ADAS showed that
they could be effective but, in some cases, offered significantly lower performance
than similar systems on passenger cars from the same manufacturer. A new van
rating scheme was developed, based on adaptation of existing passenger car
protocols for ADAS but not for full scale crash. Ratings of the whole market in
the EU have been undertaken in 2021 and 2022 and the scores have improved
substantially.
Paper No.23-0312-O
Euro NCAP mobile
progressive deformable barrier testing
Volker Sandner Allgemeiner Deutscher Automobil-Club (ADAC)
e.V. Technical Centre, Germany James Ellway The European New Car Assessment Programme (Euro NCAP),
United Kingdom Michiel Van Ratingen The European New Car Assessment Programme (Euro NCAP),
Belgium Andre Eggers, Tobias Langner German Federal Highway Research Institute (BASt), Germany
Abstract The
European New Car Assessment Programme (Euro NCAP) implemented an updated Adult
Occupant Protection assessment in 2020. This saw the adoption of the Mobile
Progressive Deformable Barrier (MPDB) frontal impact test and the use of the
THOR anthropometric test device. The procedure was developed by the Frontal
Impact Working Group (FIWG) supported by Euro NCAP and its members, alongside
representatives from both the European Automobile Manufacturers Association
(ACEA) and the European Association of Automotive Suppliers (CLEPA). This paper
summarises the implementation of this new procedure and the work of the FIWG
over the last five years. Data from official Euro NCAP testing has been
analysed to provide an overview of results from the first three years of MPDB
assessments. Euro NCAP is the first consumer rating programme in the world to
include an assessment of a vehicle's compatibility. The assessment is based
upon three measured parameters: standard deviation (SD) of the post-test
barrier face deformation, the Occupant Load Criterion (OLC) of the MPDB
trolley, and whether or not the barrier face has been crushed beyond a
designated limit. The performance of the THOR dummy and its impact on vehicle
ratings has also been examined. In particular, the assessment of chest and
abdomen compression, iliac crest loading, and acetabulum loading were
considered as they have never been included in previous assessments. An
investigation of the MPDB tests found that it is not uncommon for the diagonal
belt to slide from the shoulder clavicle towards the neck of the THOR dummy.
The effect of this belt movement has been investigated and improvements to the
dummy hardware have been considered. As the THOR dummy is also able to measure
rotational movement of the head, the group implemented a two-step approach to
evaluate brain injury criteria. The first step analysed signal-based criteria
culminating in the adoption of DAMAGE for assessment in 2023 ratings, another
world first. The group is also reviewing existing advanced brain injury
criteria that utilise FE based brain models for adoption in 2026. The test data
analysis was based on the results of Euro NCAP official tests; there was no
access to manufacturers' in-house or preliminary Euro NCAP test data.
Therefore, this paper does not address any repeatability or reproducibility
issues. The current assessment of THOR chest compression uses the maximum peak
resultant displacement of the four thoracic ribs (Rmax). The intention is to
adopt a more sophisticated chest criterion in future assessments which will be
performed alongside an evaluation of THOR certification data. Euro NCAP has
evaluated the implementation of a new frontal impact test in a consumer rating
programme and is the first such programme to utilise the THOR ATD, advanced
injury criteria and a vehicle compatibility assessment. Further developments in
the assessment are being considered and will be incorporated into the vehicle
rating scheme in 2026.
Paper No.23-0329-O
Challenges in evaluating
automated driving systems using current ADAS and active safety test track
protocols
Scott
Schnelle, Kristofer Kusano, Francesca Favaro,
Guy Sier, Trent Victor Waymo, United States
Abstract
A number of public safety stakeholders
have advocated for the application of traditional consumer-focused testing
protocols (e.g., NCAP programs) currently used to evaluate some ADAS and active
safety technologies (i.e., SAE Level 0, Level 1, Level 2) for the evaluation of
safety for Automated Driving Systems (ADSs). To gain practical insight into the
types of challenges and limitations arising from the application of these
existing test protocols to ADSs, the Waymo Driver, a SAE Level 4 ADS, was the
subject of a testing campaign that leveraged several of the most difficult
currently available ADAS and active safety test procedures. The main challenge
discovered was that most protocols designed to evaluate collision avoidance
behavior could not be evaluated as designed due to the increased capabilities
of the Waymo Driver that prevented the vehicle from even entering into a
conflict to begin with. Difficulties encountered included creating the type of
occlusions envisioned in some test protocols due to the location and
performance of the Waymo Driver's sensor suite and insufficient information in
the test procedure regarding the roadway and map information. For example, in
the occluded vulnerable road user (VRU) scenarios, the Waymo Driver could sense
the test target prior to it starting to move and couldproactively slow
down, resulting in the desired collision avoidance interaction in the scenario
not being tested. To make the test conditions representative of the intended
collision avoidance interactions in the test procedure, either extra vehicles
and/or different vehicle types were used as the occluding vehicles (e.g., large
trucks). Similarly for the car-to-car tests, a larger obstructing lead vehicle
was used for the cut-out test so the Waymo Driver could not see over the lead
vehicle. Also, without specifying additional details for the roadway that were
not in the original test procedure, the Waymo Driver would proactively slow
down due to the presence of parked cars or other roadway features on the test
track, such as intersections. Beyond these required modifications to enable the
interactions described in the test procedure, additional optional modifications
were made to the test to increase the difficulty of the test. For example, in
the NCAP cut-in test, the distance at which the vehicle was cutting in was
reduced from 7.5m to 3m to try to elicit collision avoidance behavior. For all
the test runs, including those run to specification and those with
modifications, the Waymo Driver was able to avoid collisions which would have
resulted in the highest rating for this evaluation. Our conclusion is that
existing ADAS and active safety test protocols cannot be applied as-is for an
ADS such as the Waymo Driver. The highlighted challenges result in ambiguous
requirements for both the test developers, the test facilities, and the test
site administrators. This further indicates that Level 0-2 systems need to be
separately considered from Level 4 ADS, such as the Waymo Driver. Furthermore,
the results of this testing calls into question the feasibility and utility of
adapting ADAS and active safety test for ADSs.
In order to prevent traffic accidents
due to abrupt changes in the driver's health condition, we have proposed a
non-contact type electrocardiographic sensor that monitors the
electrocardiogram (ECG) of a driver holding a steering wheel while seated.
However, the heart rate detection accuracy degrades while driving due to the
lower signal-to-noise ratio (SNR) of the ECG caused by the noise from vehicle
vibration and static electricity, among others. In this study, we propose a
method of detecting R-peaks of the ECG from the low SNR ECG signal with high
accuracy using a multi-channel one-dimensional convolutional neural network
with accelerometer signals as an input. As the results, we achieved an F-score
of 78.5% and a root-mean-square error (RMSE) of 1.99 ms. The R-peak detection
performance was significantly improved when the input data length of around
1100 ms was chosen.
Paper No.23-0048-O
Verification and validation
of machine learning applications in advanced driving assistance systems and
automated driving systems
Chung-Jen Hsu Bowhead Mission Solutions, United States
Abstract
The verification and validation
processes of machine learning applications in advanced driving assistance
systems or automatic driving systems are presented, and the processes are
implemented by using the forward collision warning of pedestrian automatic
emergency braking. Supervised learning is one of the machine learning
branches using image datasets to train the deep neural network for detecting or
identifying the target object or scenario in a vision-based application.
The verification process consists of specifying the requirements of a safety
functionality, identifying the target objects in the Operation Design Domain
(ODD) and pre-crash scenarios, and evaluating the quality and quantity of
images based on safety requirements, also the coverage of ODD and pre-crash
scenarios. The validation process consists of designing test procedures
based on the specified ODD and pre-crash scenarios, conducting a sufficient
number of tests, recording the test results, and evaluating the test results
based on specified metrics. Eight published pedestrian datasets from 2010
to 2020 are reviewed. Three datasets contain the raining condition, but
no dataset had images collected during snowing days. Fog or smoke images
are not available in all datasets, and the headlight condition is not addressed
in all datasets. The 3 datasets containing pedestrians in the nighttime
did not label the vehicle's headlight status as low or high beam. All
reviewed datasets had no annotations of pre-crash scenarios that the subject
vehicle is maneuvering or not. The validation of pedestrian detection
uses the activation of forward collision warning as the evaluation
metric. Eleven vehicles were tested in 4 pre-crash scenarios with
different pedestrian orientations and speeds: the test pedestrian crossing from
the nearside, crossing from the offside, stationary facing away, and walking
away in front of the vehicle. The vehicle speed under test is 40 kph and
the test pedestrian's speed is 5 or 8 kph. The light conditions are
daytime, nighttime with low beam, and nighttime with high beam without
streetlighting in a test track. The statistical test results show that
some vehicles under test behave inconsistently when the test pedestrian is
crossing or not crossing. Test results in the nighttime with high beam
are similar to that of the daytime; however, the test results in the nighttime
show significant variations compared with that of daytime. No trend or
similarity can be found among all vehicles under test, the same vehicle may
behave inconsistently under different light conditions and pedestrian
orientations. Also, the pedestrian detection time is longer when the test
pedestrian is not crossing for some vehicles. The vision-based machine
learning application for the vehicle safety functionality reveals the
underlying uncertainty of a deep neural network, and it results in the
inconsistent performance in differentiated ODD conditions and pre-scenarios.
Paper No.23-0055-O
Evaluation approach
for machine learning concepts in occupant protection based on multi-attribute
decision making
Franz
Plaschkies, Ketlen Possoli, Ondřej Vaculín Technische Hochschule Ingolstadt, Germany Axel Schumacher Bergische Universität Wuppertal, Germany Pedro Paulo Andrade Junior Federal University of Santa Catarina, Brazil
Abstract
The systems for occupant protection in
passive vehicle safety are primarily developed with single statistical
representations of humans, so-called Anthropomorphic Test Devices (ATDs).
Unfortunately, those ATDs cover additional features like age and body shape
insufficiently during development. Augmenting finite element simulations with a
metamodel trained by machine learning is promising to overcome this barrier.
However, the database design, the machine learning architecture, and the
requirements for quality and robustness influence each other. Therefore,
objective criteria must be defined to compare the alternatives taking cost and
benefit aspects under changing preferences into account. Having complex
criteria can be framed as a multi-attribute decision-making problem. This
paper's objective is the development of a transparent assessment scheme for
virtual statistical simulation for rapid vehicle occupant safety assessment
using supervised learning. PROMETHEE is selected as an appropriate
decision-making approach. A process, consisting of a sequential definition of the
criteria leading to the final assessment, is proposed to adapt the method in
this paper's domain. The methodology is tested on sample alternatives,
generated using a calibration-type machine learning architecture and data from
finite element simulations. The original PROMETHEE algorithm cannot handle a
vast number of alternatives. Since, typically, numerous alternatives occur
during the development of a machine learning application, a sorting-based
modification is implemented. Finally, the findings are discussed, and
recommendations for related use cases are given. The proposed method seems
applicable to the described domain and near-related ones. Moreover, multiple
tendencies between an alternative's parameters and rank can be identified in
the test samples.
Paper No.23-0136-O
Analysis method for a
traffic accident using motorcycle probe data
Osamu Ito, Takayuki Kawabuchi, Hideo Kadowaki, Yuji Takagi, Hiroki Tanaka Honda Motor Co.,Ltd, Japan
Abstract
To reduce the number of the fatalities
among the motorcyclist in Asian countries, it is necessary to analyze and
clarify the cause of the accident, however, the accident data are insufficient
in these countries for the accurate analysis. To compensate for insufficient
accident data, the authors approached to analyze the accident using the probe
data obtained from vehicles. The investigation was conducted by the riding data
acquired from the 50 cc motorcycles, including the location information in 1
second cycle, the vehicle speed and the throttle opening signals in 0.2 seconds
cycle acquired from the Global Navigation Satellite System (GNSS) and the
Electronic Control Unit (ECU), respectively. The time historical data from GNSS
and ECU were divided into 5798 trips, separated by the time interval longer than
1 minute. During all trips, there was only one accident. The acquired data were
processed by the autoencoder model to extract the characteristics of the trips
and riding behavior. The autoencoder model has the latent space between the
encoder and decoder to analyze the trips and riding behavior. The information
of trips and riding behavior in the latent space was quantified using Kernel
Density Estimation to express the anomaly of the trips and riding behavior. In
addition, riding simulations were conducted based on GNSS and ECU information
to validate the results of abnormality detection by the autoencoder. The
results showed that the accident data were classified as abnormal behavior. The
anomalies could be expressed as changes with time history. It proved that the
riding abnormalities appeared 30 seconds before the accident occurred. When the
simulation was also performed to reconstruct the accident, it was observed that
the rider was riding dangerously such as slipping past the car or accelerating
and decelerating rapidly. The authors devised a method to analyze the causes of
traffic accidents by using the autoencoder model and riding simulation. This
method is expected to improve the efficiency of accident data collection and
analysis in regions where accident data for motorcycles is lacking, such as in
developing Asian countries.
Paper No.23-0210-O
Applying AI methods on
Video Documented Car-VRU front crashes to determine generalized vulnerable road
user behaviors
Thomas Lich, Jörg Mönnich, Martin Voss Robert Bosch Corporation, Germany Patrick Lerge, Lennart Vincent Nölle, Syn
Schmitt Institute for Modelling and Simulation of Biomechanical
Systems (IMSB), Germany
Abstract
Urban traffic is characterized by
limited traffic areas, varying traffic flows and the occurrence of different
types of road users. To further advance automated mobility, the severity of
injuries sustained by vulnerable road users (VRUs) in unavoidable accidents
must be minimized. The project “ATTENTION", supported by the German Federal
Ministry for Economic Affairs and Climate Action, was set up to tackle this
issue by developing a method for the real-time prediction of VRU injury risk
using artificial intelligence (AI). The present study represents the first step
in the ATTENTION project and evaluates behavioral aspects of VRUs in real-life
car crash scenarios. Firstly, a comprehensive, hand labeled database of video
documented VRU crashes from South Korean dashcams was set up. Secondly, the
data was analyzed to determine relevant characteristics like pedestrian
pre-crash movement and behavior. Afterwards a comparison against the German
in-depth accident study database was performed. Finally, relevant scenarios
were extracted, and AI-based preprocessing was applied. Body-shape-estimation
methods were used to extract pedestrian poses and kinematics for further
statistical processing. In 9,724 video documented crashes, 369 frontal primary
collision against VRUs were deemed usable. The analysis reveals that every 4th
crash in this sample is potentially not avoidable due to physical limitations.
The VRU recognized the car before impact in every 2nd crash, possibly
performing evasive actions prior to first impact. Comparisons revealed that
31,000 similar car-VRU crashes were documented in the German In-Depth Accident
Study (GIDAS) database. The estimation of plausible shapes and kinematics was
possible in 37 of 319 pedestrian cases (12%), while 10 of 50 videos (20%)
involving cyclist could be processed. Distinct pre-crash poses and kinematics
were objectively identified and were shown to be different from standard
gait-cycle kinematics. The VRU shapes and poses were used to define average
pre-crash body shape appearances and hull-spaces for use in future human body
model simulations. The results of this study show that a VRU pre-crash behavior
can be objectively determined from low-quality in-field video data using
AI-driven methods and that it differs from regular human motion patterns.
Furthermore, it shows that this video data can be used to setup a position and
movement database. Both lay the foundation to estimate an injury risk index of
VRUs in the later stages of the ATTENTION project.
Paper No.23-0215-O
A method for efficient
generation and optimization of simulation-based training data for data-driven
injury prediction in VRU-vehicle accident scenarios
Niranjan
Ballal, Thomas Soot, Michael
Dlugosch, Niclas Trube Fraunhofer-Institute for High-Speed Dynamics,
Ernst-Mach-Institut, EMI, Germany Dirk Fressmann DYNAmore Gesellschaft für FEM Ingenieurdienstleistungen
mbH, Germany
Abstract
Urban traffic is characterized by
limited space, varying traffic flows and multiple types of road users. Despite
increasing automation and design efforts, the joint use of traffic areas poses
a particular risk for vulnerable road users (VRUs). In order to make traffic as
safe as possible, the severity of injuries to VRUs in unavoidable collisions
must be reduced. In future applications, predicting situation-specific injury
risks for VRUs in real-time using machine learning (ML) could support decision
making in determining risk minimization strategies. The predictive capability
of any ML model is determined by the quality of the used training data. While
there are no real-world training data available for injury prediction,
simulation data, which is frequently employed in passive safety engineering,
can be used as synthetic data. Since deliberate training data generation
consumes substantial resources, particular attention is focused on the
iterative generation of optimized simulation data sets. This study presents and
discusses an adaptive simulation data generation pipeline to generate
simulation data sets that reflect the overall system's behavior with the
overall goal of efficiency and sustainability. The
novel pipeline involving nine steps is divided into two phases, “Data
Generation" and “Data Exploitation". The “Data Generation" phase predominately
focusses on the adaptive strategies to generate a generalist training data set.
Along with the fundamental techniques for adaptively adding new points, metrics
for assessing the information content of the present data set and for tracking
the iterative sampling progress are also discussed in this study. Additionally,
experiments to understand the effects of batch size is conducted and the
potential use of information content metrics for process termination and
dynamic, adaptive batch size adjustment is discussed. The pipeline is initially
tested using a generic example and is then applied to a simulation setup
modeling a human head crashing onto a vehicle windshield. The observations from
applying the pipeline to the simulation setup are compared with the
observations from applying it to the generic function to evaluate the novel
pipeline. It is
shown that the pipeline is generally applicable to such real-world problems and
that the anticipated dynamic behavior of the data generation process is
confirmed in the generic and real application example. This lays fundamental
groundwork which needs to be extended along multiple routes in future work.
Paper No.23-0219-O
Prediction of all rib
deflections of THOR-ATD by means of deep neural network model
Takayuki
Kawabuchi, Yasuhiro Dokko, Hidenori Mikami Honda Motor Co.,Ltd, Japan Kota Katsushima IDAJ Co., Ltd., Japan Yosuke Nagai PHOTRON LIMITED, Japan
Abstract
The fatality rate of thoracic injury
for elderly occupants in vehicle accidents is significantly high. Its major
cause is the rise of internal organ injury rates due to an increase in the
number of fractured ribs (NFR). Therefore, NFR reduction is crucial to enhance
elderly occupant protection and is one of the key issues for achieving zero
fatalities. In order to improve NFR prediction accuracy, the previous study
proposed the criterion using the weighted averaged displacement of all ribs
(WADAR), which indicated a higher correlation coefficient with NFR than that of
the criterion, Rmax, using four Infra-Red Telescoping Rod for the Assessment of
Chest Compression (IR-TRACC) installed on the thorax of the Test device for
Human Occupant Restraint Anthropometric Test Dummy (THOR-ATD). While WADAR
requires all rib deflections, it is difficult to install IR-TRACCs on all ribs
inside the limited space in the thorax of THOR-ATD. The objective of this
research is to predict the deflections of all ribs by means of a neural network
model using time-histories of rib deflections from four IR-TRACCs and the crash
velocity without any installation of additional measurement devices. The
architecture of the neural network model is based on U-Net, which is one of the
convolutional neural network models. The model was trained by time-historical
X, Y and Z displacements of 14 ribs and the crash velocity derived from the 56
FEM simulation data, which represented frontal and oblique sled experiments
with THOR-ATD. The model learned the physical relationships among the ribs with
and without IR-TRACCs. The predicted rib deflections were validated by the
THOR-ATD experiment, where the displacements of the 2nd to 6th ribs on the left
side were measured three-dimensionally by the set of two cameras installed on
the upper and lower thoracic spines. The predicted deflections during 0 to 150
ms were processed into a resultant deflection and compared to the actual
deflection through the 2nd to 6th ribs on the left side. The maximum
differences in the peak deflection were 2.3 mm, respectively. Furthermore, the
root mean square error (RMSE) was calculated at each rib for prediction
accuracy evaluation, which resulted in minimum and maximum RMSE of 0.6 mmand 2.7 mm,
respectively. Although the number of training datasets was small, the neural
network model trained by FEM simulation data could predict all the rib
deflections with small error without physical measurement devices.
Paper No.23-0265-O
A concept to support AI
models by using ontologies - presented on the basis of German technical
specifications for lane markings
Maximilian
Grabowski German Federal Highway Research Instutute
(BASt), Germany Ya Wang Fraunhofer Institute for Open Communication Systems, Germany
Abstract
Artificial Intelligence (AI) and
Machine Learning (ML) deliver promising approaches to the development of
assisted as well as automated and autonomous driving technologies. However,
learning all possible traffic situations and outcomes is almost not feasible.
Furthermore, machine learning-based models are usually regarded as a black box,
and we cannot trace their decisions for a certain behavior. To counteract this,
we propose an ontology-based model, which integrates normative knowledge, to
support the decision making of the AI for automated and autonomous vehicles.
Since traffic rules and laws are explicitly defined in the model, we can easily
track any derived decisions, eliminating the necessity of learning all possible
traffic situations. We formalize the German Technical Specifications on Lane
Markings into an ontology for a better representation of the traffic
environment and thus improve the situational awareness of automated and
autonomous vehicles. Additionally, the reasoning capacity of an ontology
based-model allows for deriving concepts in multiple ways, which can serve as
redundant information about lane and lane markings to enhance the understanding
of the traffic situation. Finally, in contrast to learning-based models, our transparent
ontology-based model allows for the validation and verification of automated
and autonomous systems and vehicles.
Paper No.23-0326-O
A study on the
possibility of machine learning-based classification of Collision Deformation
Classification (CDC) on the KIDAS database for traffic crash reports
Minsu Ko Chungbuk National University Hospital, Korea,
Republic of Jongyoung Lee, Sangchul Kim Department of Emergency Medicine, Chungbuk National
University Hospital, Korea, Republic of
Abstract
This is a study that automatically
classifies codes based on accident data collected in the pre-hospital stage to
secure the effective time of treatment for emergency patients in traffic
accidents. In order to automatically classify the codes, learning data is
composed of VEHICLE INDEX, VEHICLE DYNAMIC, ROAD-INVIRONMENTAL INDEX, ACCIDENT
INDEX, CRASH INDEX data and CDC-code among the KIDAS data. Although this study
is primarily to create a classifier to identify CDC-codes from traffic accident
data, the main contribution lies in the development of state-of-the arts
machine learning methods that exploit correlations between different types of
attributes. The classification methodology focuses on how to automatically
determine codes using an optimal classification model and describes how to rank
them according to the degree of inclusion of traffic accident attribute
information. In the future, it is planned to derive a model for classifying the
AIS-code by combining and reflecting the classification results according to
the classification model derived from this study and patient/vehicle
safety/vehicle information/hospital transfer information among the KIDAS
accident data.
Paper No.23-0331-O
Safe control transitions:
Machine vision based observable readiness index and data-driven takeover time
prediction
Ross Greer, Nachiket
Deo, Akshay Rangesh, Mohan Trivedi University of California San Diego, United States
Pujitha Gunaratne Toyota Collaborative Safety Research Center, United
States
Abstract
To make safe transitions from
autonomous to manual control, a vehicle must have a representation of the
awareness of driver state; two metrics which quantify this state are the
Observable Readiness Index and Takeover Time. In this work, we show that
machine learning models which predict these two metrics are robust to multiple
camera views, expanding from the limited view angles in prior research.
Importantly, these models take as input feature vectors corresponding to hand
location and activity as well as gaze location, and we explore the tradeoffs of
different views in generating these feature vectors. Further, we introduce two
metrics to evaluate the quality of control transitions following the takeover
event (the maximal lateral deviation and velocity deviation) and compute
correlations of these post-takeover metrics to the pre-takeover predictive
metrics.
Paper No.23-0333-O
Salient sign detection
in safe autonomous driving: AI which reasons over full visual context
Ross Greer, Akshay Gopalkrishnan, Nachiket Deo, Akshay Rangesh, Mohan Trivedi University of California San Diego, United States
Abstract
Detecting road traffic signs and
accurately determining how they can affect the driver's future actions is a
critical task for safe autonomous driving systems. However, various traffic
signs in a driving scene have an unequal impact on the driver's decisions,
making detecting the salient traffic signs a more important task. Our research
addresses this issue, constructing a traffic sign detection model which
emphasizes performance on salient signs, or signs that influence the decisions
of a driver. We define a traffic sign salience property and use it to construct
the LAVA Salient Signs Dataset, the first traffic sign dataset that includes an
annotated salience property. Next, we use a custom salience loss function,
Salience-Sensitive Focal Loss, to train a Deformable DETR object detection
model in order to emphasize stronger performance on salient signs. Results show
that a model trained with Salience-Sensitive Focal Loss outperforms a model
trained without, with regards to recall of both salient signs and all signs
combined. Further, the performance margin on salient signs compared to all signs
is largest for the model trained with Salience-Sensitive Focal Loss.
Thursday, April 6, 2023, | 08:30-12:30
Chair: Peter Striekwold, The Netherlands | Co-Chair: Toshiya Hirose, Japan
TRACK A | Room: G301+G302
PEER REVIEW
PAPER No.23-0051-O
The role of driver
behavior models in the simulation-based safety assessment of automated driving
Alexandra Fries,
Felix Fahrenkrog, Arun Das BMW AG, Germany Marcus Mai Technische Universität Dresden, Germany
Research
Highly automated driving
systems are on the edge of entering the market. Before this, the safety of
these systems needs to be assessed prospectively. BMW has introduced a holistic
approach that uses stochastic traffic simulations. These simulations require a
realistic driver behavior modeling ranging from performance in non-critical
everyday driving towards performance in critical situations. In the simulation
the model represents a part of the baseline for the comparison with automated
driving as well as behavior of the surrounding traffic. The associated research
question is: how should a driver model for this purpose be designed?
Methods
Therefore, BMW
has developed the Stochastic Cognitive Model (SCM). SCM models cognitive
processes in traffic situations which range from information acquisition by
gaze behavior, recognition of situations from the visual information and
reaction to the situation. The model combines the cognition aspects of humans
with stochastic processes and parameters to obtain a variation in the virtual
driver population. The paper describes the cognitive approach of SCM.
Special emphasis will be put on the visual attention modeling because this is
key to traffic interaction modeling. The recognition of the situation and the
reaction is highly dependent on the information perceived by the gaze behavior.
Gaze behavior in SCM is modelled through stochastic processes by applying
gaze distribution matrices which specify frequency of gaze allocation and gaze
duration. Gaze directions are further influenced by top-down or bottom-up
attention. Top-down is the voluntary allocation of attention according to
drivers' intentions and goals whereas bottom-up attention is the involuntary
allocation of the attention to salient stimuli in the environment. Data as input
for the models has been recorded in BMW naturalistic driving studies and
simulator experiments.
Results
SCM will be
applied in traffic scenarios in which the gaze behavior and reaction of SCM is
evaluated and compared to real-world data. Especially a non-critical as well as
a critical traffic scenario will be analyzed regarding certain parameters like
gaze direction, brake reaction time and time-to-collision in the predefined
situations. Due to the stochastic approach of SCM a collective of virtual test
drivers is evaluated and compared.
Discussion
The question
which arises for the gaze behavior and for the overall behavior of SCM is the
trustworthiness of the simulation results. Therefore, one main focus lies in
the validation and verification of the driver model. The behavior of SCM is
evaluated both in short conflict situations and in larger traffic endurance
simulations. These validation and verification aspects and the related
toolchain will be presented in the paper.
Conclusion
The final paper presents the SCM
driver behavior modeling and discusses its role in the safety assessment
approach of automated vehicles. This includes a description of cognitive
processes in combination with stochastic variations to represent realistic
traffic in the simulation. Special focus will be placed on the gaze behavior of
the model as this is the input for the sequential cognitive processes.
Realistic driver and traffic behavior is shown in certain critical and
non-critical scenarios and compared to real-world data.
Paper No.23-0072-O
A pragmatic approach
to safe operation for driverless shuttles during development
Christopher
Pinke, Matthias Strauß Continental Autonomous Mobility Germany GmbH,
Germany Danilo Da Costa Ribeiro, Wolfgang Schramm Continental Autonomous Technologies GmbH, Germany
Abstract
Driverless shuttles are a modern
vehicle platform designed to operate autonomously, constituting a very
promising building block of future mobility solutions. At Continental, there is
a long experience with these types of vehicles. In this paper, some of this
experience regarding operating such vehicles during development is shared. In
particular, the focus is on how a safe operation can always be ensured. To this
end, a release process for such an operation, how a pragmatic safety assessment
can be done and some of the peculiarities of driverless shuttles are presented.
PEER REVIEW Paper No.23-0099-O
How certain are we
that our automated driving system is safe?
Erwin de Gelder,
Olaf Op den Camp TNO, Netherlands
Research
Regulations are
currently being drafted by the European Commission for the safe introduction of
automated driving systems (ADSs) with conditional or higher automation (SAE
level 3 and above). One of the main challenges for complying with the drafted
regulations is to prove that the residual risk of an ADS is lower than the
existing state-of-the-art without the ADS and that the current safety state at
European roads is not compromised. Therefore, much research has been conducted
for estimating the residual risk of an ADS. One proposed method for estimating
the risk is data-driven scenario-based assessment, where tests are partially
automatically generated based on recorded traffic data. Although this is a
promising method, uncertainties in the estimated risk arise from, among others,
the limited number of tests that are conducted, the limited data that have been
used to generate the tests, and inaccuracies in the same data. This paper
addresses the following question: “Given the limitations of the data and the
number of tests, what is the uncertainty of the estimated residual risk of the
ADS?"
Methods
To compute the
residual risk, parameterized test scenarios are based on large-scale
collections of road scenarios that are stored in a scenario database. The
exposure of the scenarios and the parameter distributions are estimated using
the data as well as confidence bounds of these estimates. Next, virtual
simulations are conducted of the scenarios for a variety of parameter values.
Using a probabilistic framework, all results are combined to estimate the
residual risk as well as the uncertainty of the estimated risk.
Results
The results are
used to provide confidence bounds on the calculated fatality rate in case an
ADS is implemented in the vehicle. For example, using the proposed
probabilistic framework, it is possible to claim with 95% certainty that the
fatality rate is less than 10-7 fatalities per hour of driving. The proposed
method is illustrated with a case study in which the risk and its uncertainty
are quantified for a longitudinal controller in 3 different types of scenarios.
The code of the case study will be made publicly available.
Discussion
If results show
that the uncertainty is too high, the proposed method allows to answer
questions like “How much more data do we need?" or “How many more (virtual)
simulations must be conducted?" Therefore, the method can be used to set
requirements on the amount of data and the number of (virtual) simulations. For
a reliable risk estimate, though, much more data are needed than the data that
have been used in the case study. Furthermore, since the method relies on
(virtual) simulations, the reliability of the result depends on the validity of
the models used in the simulations.
Conclusion
The presented case study illustrates
that the proposed method is able to quantify the uncertainty of the estimated
residual risk of an ADS. Future work involves incorporating the proposed method
into the type approval framework for future ADSs of SAE levels 3, 4, and 5,
such as proposed in the upcoming EU Implementing Regulation ADS.
Paper No.23-0108-O
Research of LSTM model
for vehicle control system of Automated Driving Systems (ADS)
Kaisei Honda, Tasuku Yamazaki, Tomohiro Baba, Shoko Oikawa, Toshiya Hirose Shibaura Institute of Technology, Japan
Abstract
Research Question/Objective: This
study aims to construct a long short-term memory (LSTM) model of the vehicle
control system for automated driving systems (ADSs) that does not cause
annoyance or distrust. Furthermore, this study investigates the effect of LSTM
hyperparameters on model accuracy. A survey showed that certain drivers did not
use levels 1 and 2 of the ADS function because they were annoyed with the
driving behavior of the ADS-controlled vehicle. Although the driving behavior
of the ADS-controlled vehicle causes distrust in passengers, it cannot
effectively enable safe driving. This study focuses on a novel vehicle control
method that reduces annoyance and distrust in passengers and contributes to the
safe operation of ADSs. These control methods involve the application of a long
short-term memory (LSTM) model that learns long-term time-series data. This
system enables the construction of ADS control algorithms from LSTM models based
on personalized driver operations during ordinary driving. Methods and
Data Sources: LSTM models were constructed for highway driving in the following
three driving scenarios. Scenario-1: following a preceding vehicle, Scenario-2:
passing a preceding vehicle at low speed with lane change, Scenario-3: a sudden
lane change by a vehicle in the passing lane in front of the vehicle. The
effect of LSTM hyperparameters on the accuracy of the LSTM model was
investigated for each driving scene. The data of these models were sourced from
an experiment using a driving simulator conducted to determine driver
behavior. Results: The results verified the accuracy of the model that
simulated the driving operation of the driver. The model accuracy was improved
by setting LSTM hyperparameters. In Scenario-1, the number of units, learning
rate, and the number of epochs affected the coefficient of determination. The
coefficient of determination tends to be particularly high for a large number
of units. In Scenario-2, unlike Scenario-1, a large number of units was not
required to obtain a high coefficient of determination. The coefficient of
determination did not change with the epoch. In Scenario-3, similar to
Scenario-1, the number of units, learning rate, and epoch affected the
coefficient of determination, whereas the coefficient of determination
decreased at epochs above 800. Discussion and Limitations: In each
scenario, the hyperparameters affecting the accuracy were different. A
limitation of this study is that it focuses on the driver model. The LSTM model
applying ADS was evaluated. Conclusions: For the ADS control algorithm
(SAE Levels 3, 4, and 5), we constructed LSTM models that reflect the
characteristics of personalized drivers. The results showed that the LSTM hyperparameters
affecting the coefficient of determination tended to differ among different
scenarios. In the future, evaluation of the effectiveness of the LSTM model
when applied to ADS is necessary. Novel control systems for ADS with LSTM
models contribute to the development of ADS system design.
Paper No.23-0121-O
Capability-based
routes for development, testing and operation of safe automated vehicles
Moritz Lippert,
Hermann Winner Institute of Automotive Engineering, TU Darmstadt,
Germany
Abstract
Ensuring safety of automated vehicles
(AVs) within their operational design domain (ODD) is essential for a release.
In some parts of the ODD, ensuring safe operation is more challenging,
requiring more sophisticated driving capabilities. For example, the same
intersection requires different capabilities depending on the selected turn,
i.e., if driving right, left, or straight ahead. To guarantee safe operation,
only route sections for which capabilities for safe driving are available and
validated should be selected. So far, the direct relationship between routes
within ODDs and the driving capabilities of AVs has not been explicitly
addressed. This paper presents for the first time an approach to identify
routes with driving requirements that do not exceed driving capabilities of
AVs. To this end, this approach builds on the Behavior-Semantic Scenery
Description (BSSD), which links behavioral demands for AVs directly to the
scenery as a central element of the ODD. Based on the BSSD, route-based behavioral
requirements are derived. Geometric characteristics of the scenery are used to
specify driving requirements and driving capabilities that can be matched as a
function of route and developed matching criteria. This matching is integrated
into a conventional route planner, which as a result determines routes that are
drivable based on the driving capabilities of an AV. The application to a real
road network shows that the identification of capability-based routes is
generally possible. Different intersections demand different requirements and
lead to different routes. Nevertheless, several challenges are discussed that
need to be overcome for a real-world application for development, testing, and
operation of AVs.
Paper No.23-0126-O
Towards modeling
driver performance within crash-relevant scenarios as virtual reference for the
safety of automated vehicles
Hendrik Weber, Lutz Eckstein Institute for Automotive Engineering (ika), RWTH Aachen
University, Germany Felix Beringhoff RWTH Aachen University, Germany Johanna Josten fka GmbH, Germany
Abstract
Technological advancements have shown
the viability of Automated Driving (AD) and have created high expectations on
its benefits – especially in terms of safety. An important step for the
introduction of AD on public roads is providing an acceptable proof of AD's
positive risk balance compared to today's traffic consisting of human-driven
vehicles. Simulation of scenarios has become an essential tool for such
analyses, since field operative tests have been shown infeasible as only means
for such proof. Nonetheless, data is needed from which to derive human driver
behavior as a reference within simulated scenarios. This paper presents an
approach for modeling human driver behavior within defined scenarios to serve
as a reference for AD. As a fundamental step to establish a suitable reference,
we outlined the architecture of a parameterizable model of driver performance
within crash-relevant scenarios, in which the driver model switches from a
continuous control to a reactive behavior. The structure is based on
well-established concepts like abstraction levels for the driving tasks,
cognitive processes, and steps within information processing. A decision
tree-like structure serves as guidance for the modularization of the driver
reaction within different scenarios, which allows creating modules of
decision-making processes as well as implementation of possible reactions
within a scenario. To show the feasibility of the architecture and modules, and
to demonstrate the applicability of the model, we conducted a driving simulator
study of a scenario with a vehicle crossing from the right. Within the
scenario, we varied the configuration of the potential crash (ego striking and
borderline case) as well as apply two values of the available time to react.
The study follows a within-subject design with 24 participants. The observed
reaction choice, time and intensity were measured and then used to parameterize
the driver model. Braking was the most frequently observed driver reaction,
while potential crash configuration apparently influences the reaction choice.
The observed driver behavior was in line with assumptions based on the state of
art, which were used for the initial architecture and decision making of the
developed driver model. Re-simulating the scenario with the parameterized model
led to a similar frequency of crashes as in the simulator study. The experiment
provided evidence that the driver model is built on reasonable assumptions for
structuring the decision-making process and modeling dependencies between
situational variables and reaction parameters. Due to sample characteristics
such as age, gathered parameters cannot serve as a general reference. However,
it is not expected that a more diverse sample will disprove the assumptions for
the model architecture. The theoretical considerations for modeling the
decision-making process and its dependency on situational variables make
apparent which complexity lies within modeling driver reactions. The proposed
model for driver performance within crash-relevant scenarios aims to serve as a
reference to prove the positive risk balance of AD. It provides a clear path
for the establishment of a general reference model. Yet, the paper shows that
the establishment of a baseline for all relevant scenarios comes with a
tremendous effort and complexity.
Paper No.23-0174-O
Adapting approval
regulations to accommodate automated vehicles
Matthias Seidl,
Mervyn Edwards, Kostas Kourantidis, Jack
Radcliffe, Tadas Andriejauskas
Tim Barlow Transport Research Laboratory (TRL Limited), United
Kingdom Tony Soper UTAC, United Kingdom
Abstract
The UK government are committed to
bringing forward legislation to allow the safe and secure deployment of
self-driving vehicles, as set out in the recent policy paper Connected &
Automated Mobility 2025: Realising the benefits of self-driving vehicles in the
UK. As part of the Connected and Automated Vehicles Process for Assuring Safety
and Security (CAVPASS) programme, TRL was commissioned to propose approaches to
vehicle classification, and suitable technical requirements for aspects not
related to the Automated Driving System (ADS). These included crashworthiness,
occupant protection, protection of Vulnerable Road Users (VRUs), and the
lighting, braking and steering systems. The initial focus of this work was on
Low-Speed Automated Vehicles (LSAVs). The work involved selection and
adaptation of existing pre- and post-deployment regulation to enable it to be
applied to LSAVs. A main part was the adaptation of the technical regulations
for M- and N-category vehicles, laid down in Great Britain's Road Vehicles
(Approval) Regulations 2020 (SI 2020 No. 818), which implements retained
Regulation (EU) 2018/858. The study proposed the introduction of two new
vehicle categories (for LSAVs with and without occupants, respectively) to
allow approval of designs not compatible with the M- and N-category
definitions, such as passenger shuttles with six seats and space for standing
passengers, or goods vehicles without any seats. Of 132 technical items
collated from the existing body of regulations, 65 were found to be generally
applicable for LSAVs with occupants, and 53 for LSAVs without occupants.
Technical clarifications for regulations were developed relating to references
to the driver or driver's seat, controls, warnings, and tell-tales and relating
to bi-directional vehicles in general. The study further found that a general
permission to carry standing passengers in light vehicles could present
unreasonable risks to occupants in braking manoeuvres or collisions, but that
it could be safe in some Operational Design Domains (ODDs). A concept was
proposed which offers manufacturers a choice between two Crashworthiness
Approval Levels (CALs). The less demanding CAL allows standing passengers but
restricts the subsequent ODD of the vehicles. VRU impact protection was a high
priority due to the expected operation in areas with a high density of
pedestrians and cyclists. However, LSAV aspects such as their typically
flat-fronted shape cause issues for the application of the current regulation,
so modifications were proposed. Low-speed vehicles are not in widespread use
today, which means no directly relevant real-world collision data was available
to base safety decisions on. The guiding principle applied in this study was to
provide 'at least equivalent safety', i.e., to offer safety levels relating to
non-ADS aspects, which, based on the limited data available and expert
judgement, are comparable to or better than those of current vehicles used in
similar scenarios. This study proposes a novel approach to link approval regulations
to the vehicle's ODD and a set of technical requirements for non-ADS-related
aspects of passenger- and goods-carrying LSAVs, which could help enable the
approval of new vehicle concepts. The proposals have been presented to the
United Kingdom Department for Transport for consideration.
Paper No.23-0224-O
Evaluation of ADS safety
metrics with logged vehicle trajectory data
Xintao Yan University of Michigan, Department of Civil and
Environmental Engineering, United States Shuo Feng, David J. LeBlanc, Carol
Flannagan, Henry Liu University of Michigan Transportation Research Institute,
United States Alrik Svenson National Highway Traffic Safety
Administration (NHTSA), United States
Abstract
Assuring safe operation remains as one
of the main challenges for developing and deploying automated driving systems
(ADS). Real-time safety risk metrics may play important roles in
calculating a risk measure of driving situations. Although a number of
safety metrics have been proposed previously, it is difficult to compare
different safety metrics and assess their performance because different
behavioral assumptions underly for each. In this paper, a method to
assess the behavior of safety risk metrics by determining the subject vehicle
(SV) situational safety using logged vehicle trajectory data is proposed.
Specifically, it is examined whether the SV is in a collision unavoidable
situation at each moment, given the near-future trajectories of all surrounding
principal other vehicles (POVs) recorded in the dataset after this moment.
The main benefit of using logged vehicle trajectory data is the
elimination of behavior prediction errors caused by model assumptions and
approximations. This establishes a ground truth for crash outcomes independent
of the risk metrics. Using the proposed methodology, the performance of
different real-time safety metrics can be evaluated using simulated and/or
real-world vehicle trajectories. The proposed methodology also has the
potential to be applied in scenarios with vulnerable road users (VRU)
interactions. In the case study, three real-time safety metrics are
considered: time-to-collision (TTC), the PEGASUS Criticality Metric (PCM), and
the Model Predictive Instantaneous Safety Metric (MPrISM). The results
can help practitioners to better understand the characteristics and
applicability of different safety metrics for different situations. The
evaluation results can also help researchers improve and refine existing safety
metrics.
Paper No.23-0345-O
Assurance through
safety cases—There's a claim for that
Nat Beuse,
Chan Lieu Aurora, United States
Abstract
Designing, developing, testing, and
deploying an Automated Driving System (ADS) is challenging for a variety of
reasons, not the least of which is that there are no defined Federal Motor
Vehicle Safety Standards that govern ADS performance requirements. While there
are a growing number of relevant industry developed consensus standards and
best practices, developers still need to take it upon themselves to define and
ensure safety assurance for an ADS. A safety case-based approach is an
appealing way to provide such assurance. A safety case is a structured
argument, supported by evidence, intended to justify that a system is
acceptably safe for a specific application in a specific operating environment.
A structured argument is important because an argument without evidence is
baseless, and conversely evidence without an argument is trivia, or just a set
of facts without anything to bring it together. While not entirely new—safety
cases have been incorporated into other industries, including oil and gas exploration,
nuclear energy, aviation, rail, and medical devices—safety cases are novel in
the automotive sector. A safety case is both flexible and rigorous. It is
flexible because it provides the developer with the latitude to determine what
claim to make, and it is rigorous because there must be evidence to
substantiate it. For example, there are now several standards and public
guidancespanning
many important topics related to the development and safe operations of AVs.
These topics include functional safety, behavioral safety, and safety assurance
for machine learning systems. The emergence of these standards provides a
common baseline that all AV developers can consider and incorporate. How an ADS
developer implements these standards can be the basis of a safety case claim
related to adhering to industry standards. This presentation will present
Aurora's experience and lessons learned in developing and implementing its
Safety Case Framework. This includes integrating these standards into the AV
development process, as well as how vehicle product engineering requirements, enterprise-wide
processes, and operational elements (such as a Safety Management System) are
incorporated into the development of an ADS. A safety case-based approach is
important to ensure that the integration of many new, overlapping standards is
managed correctly. And ultimately, a safety case-based approach provides
transparency and insight into safety assurance.
Thursday, April 6, 2023, | 08:30-12:30
Chair: Aloke Prasad, United States | Co-Chair: Nils Lubbe, Sweden
TRACK B | Room: G303
Paper No.23-0058-O
Classifying diverse
population for adaptive restrain system by using finite element human body
models
Chin-Hsu
Lin General Motors (GM), United States
Research
Vehicles are
expected to meet standard crash tests requirements for both structural and
occupant performance specified by governments and consumer advocacy groups.
These tests command a specific ATD size in well-defined seating position with a
certain impact speed of the vehicle or a moving barrier. In these standardized
tests, typically, the 5th percentile female dummy and 50th percentile male
dummy are specified, and the vehicle's occupant restraint system is optimized
simultaneously for these dummies. With adaptive restraint system, the system
can be optimized independently for 5th percentile, 50th percentile, and 95th
dummies to maximize the protection. The objective of this research is to
establish a methodology to classify diverse population such that a best set of
optimized restraint systems derived from dummies can be tailored to an
individual of any size.
Methods
A validated
finite element vehicle sled model was selected for this study. US-NCAP
standardized crash condition was simulated to optimize three vehicle restraint
system designs for HIII small female, midsize male, and large size male
independently. Twelve design variables of the airbag, seatbelt systems, and
steering column were selected for such optimization. Fifty female and fifty
male human body models (HBMs) morphed from GHBMC M50-OS model were used to
represent diverse driver populations with various age, stature, and BMI of the
US population. Automated process was developed for positioning the HBMs into
the driver position for occupant safety simulations. The three optimized
restraint systems developed for small female, midsize male, and large size male
dummies independently, were then applied to each of the 100 HBMs. To evaluate
the safety performance of the three optimized designs on each of the HBM, the
joint probability of injury for each of the simulations were calculated.
Results
Three sets of
restraint systems were optimized for the Hybrid III 5th, 50th, and 95th by
minimizing the occupant injury risk in a regulated 35mph impact condition. Each
of the three sets of restraint systems was used to assess the safety
performances of each of the 100 HBM's. Based on the best fit restraint system
selected for each of the 100HBM's, the boundaries dividing the diverse
population are drawn. The population classification methodology is established
for a vehicle with adaptive restraint system.
Discussion
The vehicle pulse
used in this study was NCAP 35mph rigid barrier crash pulse only and the
occupant classification boundary based on this pulse may change for lower speed
or different types of barriers impacts. The 100HBMs were developed based on
simplified GHBMC model and the classification boundary could be different if
detailed GHBMC models were used to morph the 100 HBMs.
Conclusion
The processes discussed in this study
show the potential of classifying a diverse population based on the best-fit
restraint system from the three systems which were optimized originally for the
dummy sizes: 5th female, 50th male, and 95th male.
Paper No.23-0092-O
FE analyses of the lap
belt interactions with the pelvis for diverse occupants in various sitting
postures
Yoshihiko
Tanaka, Yuya Takeuchi, Yuqing Zhao, Na Yang, Koji
Mizuno Nagoya University, Japan Yoshinori Tanaka, Naruyuki Hosokawa National Traffic Safety and Environment Laboratory, Japan
Abstract
Passengers of different body shapes
and sizes such as male, female, obese, and lean can sit in a car seat assuming
various postures. This study aims to understand the interaction of the lap belt
with the pelvis in a vehicle frontal impact scenario for occupants of various
shapes, sizes, and sitting postures. A mid-size male Total HUman Model for
Safety (THUMS) was morphed to develop a high and a low body mass index (BMI)
human model using computer tomography (CT) images of sitting participants
wearing a lap belt. Frontal impact finite element (FE) simulations were
conducted for various occupant models (THUMS high-BMI, AM50, low-BMI, AF05, and
Hybrid III AM50, AF05) under standard, reclined, and slouched sitting postures
in the rear seat. The lap belt interactions with the anterior superior iliac
spine (ASIS) were compared using the belt-pelvis angle and the overlap of the
lap belt with the ASIS in the lap belt direction (belt-ASIS overlap). From FE
simulations, submarining occurred more in the reclined and slouched postures
than in the standard posture because of the large initial rearward pelvis tilt.
Submarining occurred in fewer cases in the high-BMI model due to smaller pelvis
rotation and larger belt-ASIS overlap than in other models. In the THUMS AF05,
even though the belt-ASIS overlap was comparable, the pelvis began to rotate
earlier and rotated more than in male models. The pelvis of Hybrid III showed a
small initial tilt and rotation angle, resulting in fewer submarine occurrences
than human body models. Submarining occurred in more cases in the slouched
posture than in the reclined posture. This is because the belt-ASIS overlap was
smaller in the slouched posture due to the shallow belt angle. In this study, a
new parameter, the belt-ASIS overlap in the lap belt direction, was proposed to
evaluate the belt engagement with the ASIS. The occurrence of submarining in
various occupants and postures could be examined by using the lap belt-pelvis
angle and the lap belt-ASIS overlap. These two parameters will be useful in
designing a restraint system to interact with the pelvis in various conditions.
Paper No.23-0120-O
Evaluation of seatbelt
use among pregnant women in Sweden
Anna
Carlsson, Beshara Sawaya Chalmers Industrial Technology (Chalmers Industriteknik),
Sweden Helena Stigson Folksam Insurance Group, Sweden
Abstract
A digital questionnaire was
distributed through social media targeting women who were or had been pregnant.
The primary objective was to investigate self-reported seatbelt use and misuse
during pregnancy. The second objective was to study if, and to which extent,
women had received information regarding seatbelt use and how to wear it during
pregnancy. The survey of 2,030 women who were or had been pregnant showed a
total seatbelt wearing rate of 99%. However, 39% were wearing the seatbelt
wrongly. In 35% of cases, the shoulder section of the seatbelt was incorrectly
positioned, and the lap section of the seatbelt in 8% of cases. In 4% of cases,
both the shoulder and lap belt parts of the seatbelt were incorrectly
positioned. The majority (66%) had not received any information regarding
proper seatbelt use during pregnancy. Of the 700 women (34%) who had received
information, most of them had actively sought out information about how the
seatbelt should be worn during pregnancy. This subgroup had significantly lower
misuse rate, although a third of the group wore the seatbelt incorrectly. Very
few (6%), had received information via a health care provider. Present data
highlight the need for improved seatbelt fit for pregnant women. The result
from the survey shows that misuse was lower among the women who actively
searched for information regarding how to wear the seatbelt. To reach other user
groups, it should be a priority for several stakeholders to communicate
information regarding proper seatbelt use during pregnancy.
Paper No.23-0176-O
Comparison of the impact
kinematics of an elderly female, the HIII 50th male and the HIII 5th female
dummies as drivers, front passengers, and rear passengers in full-width frontal
impacts
Andreas
Schäuble, Florian Zippel, Thilo Wackenroder, Peter Rücker DEKRA Automobil GmbH, Germany Thomas Kinsky Humanetics Europe GmbH, Germany
Abstract
The objectives of this study were to
analyse and compare the impact kinematics of an early prototype version of an
Elderly Female, the HIII 50th Male, and the HIII 5th Female dummies as drivers,
front passengers, and rear passengers in full-width frontal impacts. Three
full-width frontal impact tests were conducted with a popular midsize station
wagon based on Regulation UN R137 – except for the front passenger seat, which
was adjusted in its longitudinal mid-position instead – in which the different
ATDs were either placed in the driver, front passenger, or right back seats.
The measured loads indicate that second-row seats offer less protection than
first-row seats. The HIII 50th Male dummy experienced the greatest torso
forward rotation on all seats, with changes in the forward leaning angle of
both the Elderly Female and HIII 5th Female dummies dependent on their
respective seat positions. More research into the biofidelity of the Elderly
Female Dummy is necessary to improve ATD design and to develop injury
assessment reference values and injury risk functions.
Paper No.23-0186-O
Assessment of
passenger safety in future cars - Identifying the real-world needs towards
safety system development
Lotta Jakobsson,
Katarina Bohman, Isabelle Stockman, Pernilla
Nurbo Volvo Cars, Sweden Martin Östling, Karl-Johan Larsson, Bengt
Pipkorn Autoliv Research, Sweden Mats Svensson, AnnaLisa Osvalder Chalmers University of Technology, Sweden
Abstract
Future cars will likely include
further collision mitigation systems, seat positions and seating configurations
compared to current cars, in addition to an increased degree of shared mobility
solutions. At the same time the population is becoming older and the diversity
in car passenger dimensions is growing. This calls for assessment tools and
evaluation methods beyond the current standardized crash test methods. This
paper summarizes the results of a Swedish research project on how to assess the
protection of the heterogeneous population of passengers (i.e., non-drivers) in
future car crashes, focusing on restraint interaction. With the overall purpose
of further improving passenger protection, the specific aims were to achieve
method developments based on the enhancement of tools (physical and virtual
human substitutes) as well as to create knowledge on passenger protection
needs. This comprehensive research project combined multiple competencies and
international collaborations, and a large number of studies have been performed
using different methods. The applied methods include real-world crash dataanalyses to
identify scenarios and situations, crash testing and simulation, and
additionally user-studies conducted in cars to evaluate sitting posture,
beltfit, kinematics, comfort, experiences, and attitudes. Furthermore, the
project included studies on crash test dummies (ATDs) and Human Body Models
(HBM). Moreover, adult morphed HBMs were developed in various sizes, ages, and
sexes, for investigating various protection principles. In novel studies, crash
interventions strategies were applied to predicted residual crash
configurations. User-studies provided evidence of self-selected passenger
postures in real car settings and, thus, deviations from standardized ATD
positions. The importance of body shape was highlighted in a beltfit user-study
including older adults. Essential booster design parameters were identified for
children in upright and reclined seat positions. Restraint principles were
investigated for adults in reclined seat positions and with the seat in rearward
positions, away from the frontal airbag and knee bolster, along with an
evaluation of the capabilities of the assessment tools. The adult HBM morphed
to various sizes, ages and sexes were validated for prediction of in-crash
kinematics in different impact scenarios and provided enhanced insights in
passenger protection assessment compared to the three standardized sizes of
ATDs. Simulations with PIPER6y, a child-sized HBM, emphasized the importance of
vehicle-booster-user system interaction. The results from the research project
provided input to safety system development, ATD/HBM design, assessment methods
development, and a number of identified research challenges for future work.
Specifically, there is a needto further explore car passenger interaction
with the restraint system in terms of seat positions and variations in body
sizes, shapes, and postures. The inclusions of the heterogeneous population
into more advanced tools such as HBMs are essential, acknowledging that when
moving closer to “zero injuries", the situations to address are more unique and
specific. Although a large range of studies using different methods was
conducted, many challenges still remain to cover the entire scope of passenger
safety in future cars.
Paper No.23-0228-O
A study on the method
to reduce thoracic injury in frontal crash using elderly human and THOR FE model
Kazunori
Maehara, Yasuhiro Dokko Honda R&D Co., Ltd, Japan Kazuki Ohhashi Honda Techno Fort Co., Ltd., Japan
Abstract
In Japan, the ratio of the elderly
in traffic accident fatalities has been increasing, and the thorax is the most
frequently injured body region. Therefore, preventing chest injury to the
elderly is one of the key issues to achieve zero fatalities. For this reason,
several detailed analyses of the chest injury mechanism have been performed
using elderly human body models (HBM). In a previous study, under frontal crash
condition, it was observed that the forward motion of the internal organ and
the forward rotation of the upper torso push up the lower ribs, potentially
leading to rib fractures. In this study, a novel occupant restraint concept was
devised that could reduce chest injury due to the mechanism above, and its
effectiveness was verified using an elderly HBM and THOR. On the devised
restraint system, a pair of shoulder belts that pass from left and right sides
of the occupant shoulder to the same sides of flank were placed. The aim of
them was dispersing the restraint force applied to the thorax of an occupant. Amembrane was
placed wrapping the abdomen between the two shoulder belts, which aimed to
reduce the protrusion of the internal organ during a frontal crash. For the
devised restraint system, a series of CAE calculation using the elderly HBM was
performed in the two crash conditions of FR56K and OMDB in comparison with the
conventional 3P belt, and the effect for reducing the number of fractured ribs
(NFR) was confirmed. Then, another series of CAE calculation using the THOR FE
model was performed in the same conditions, and several chest injury criteria
such as Rmax, PC Score, TIC_NFR, and TIC_NSFR were calculated. Finally, injury
probabilities for these criteria of THOR and NFR of the HBM were compared.
Comparing the devised restraint system with the 3P belt, NFRs of the elderly
HBM were significantly reduced, and all chest injury criteria of THOR were
reduced, under both load cases. In the OMDB condition using the devised system
and THOR, the chest deflection at inner lower was the largest, and Rmax was
relatively high than other chest injury criteria. In the same condition,
TIC_NSFR showed the best correlation with the NFR of the elderly HBM. It was
considered the reason why Rmax was high on OMDB was that THOR had a more
protruded ribcage around the lower region than the elderly HBM, which caused
higher concentrated load on this region pushed by the shoulder belt. The reason
why the TIC_NSFR on OMDB was low was considered to be that the devised system
restrained the chest evenly on the left and right, and the value of the term
that indicates the left-right difference of the upper chest deflection in the
TIC_NSFR formula became smaller. It was found that the devised chest restraint
system could significantly reduce rib fractures of the elderly HBM in a frontal
crash. It was also found that when the devised system was evaluated with THOR,
every chest injury criterion was reduced.
Paper No.23-0277-O
Comparison of injury
risk of different child restraint systems between regulated and realistic
frontal impact tests
Akos Kriston, Dalia Broggi, Fabrizio Re, Fabrizio Minarini, Christian Bonato European Commission (JRC), Italy
Abstract
Motorized vehicle crashes represent
the highest injury risk for children. Furthermore, new devices and new
transportation applications potentially bring new challenges and injury risks.
Therefore, the main objective of this work is to analyze the safety performance
of seat belt alone, booster seat and belt guide only devices in frontal impact
tests under regulatory and realistic conditions. We analyzed the kinematics of
the dummy, calculated the injury risks, and compared it with the meta-analysis
of past published crash analysis complemented with the most recent accident
data retrieved from the EU CARE database. We calculated the risk attributable
to the studied restraint solutions and test conditions. Test on belt guide only
devices show that they are statistically equivalent to seat belt alone
solutions. Therefore, replacing an appropriate booster seat with belt guide
only devices potentially increase the number of injured children by 33% (95
confidence interval:16%, 50%). Finally, we performed gap analysis to improve
the fitness-for-purpose of regulations for future mobility applications.
Paper No.23-0285-O
Mapping the path
forward toward equity in crash safety: Recommendations from an expert workshop
Jessica
Jermakian, Raul Arbelaez, Matthew Brumbelow Insurance Institute for Highway Safety, United States
Abstract
Crash testing historically has focused
on the use of midsize male anthropomorphic test devices (ATDs). These tools
and, more recently, ATDs representing a small female have been used to drive
improvements for a diverse population with many differences that can affect
injury risk. However, there are still gaps in protection for some population
groups that may require different strategies to optimize their protection. To
address this, 23 experts from industry, academia, and government convened in
October 2022 for a 2-day workshop to reflect on opportunities and challenges in
protecting both male and female occupants of different ages and sizes. Workshop
participants included experts in biomechanics, behavioral science, human
factors, communications, and policy. The discussion focused on how current
tools and resources can be used to better protect a range of occupants and what
future tools and data are needed to improve safety evaluations and incentivize
robustness across the occupant protection design space. This paper reports on
the workshop discussion and recommendations along the following key themes: the
need to understand the current state of occupant protection to identify
priority populations; the need for fundamental data on the populations of
interest to improve ATDs and computational tools; computational modeling and
human body models as critical tools for studying injury causation and
evaluating countermeasures; currently available tools and strategies that can
benefit a diverse population; and the importance of collaboration. The
recommendations provide several paths to improve safety today and work toward
improved protection in the future for a broader range of occupants with diverse
needs.
Paper No.23-0323-O
An NCAP rating for females
Kennerly
Digges Automotive Safety Research Institute, United States DAINIUS DALMOTAS D.J. Dalmotas Consulting, Inc., Canada Priya Prasad Prasad Engineering, Inc, United States
Abstract
This paper defines NCAP rating factors
that would be useful to improve the safety of females in frontal crashes.
The study is based on an analysis crash tests available on the NHTSA website
and analysis of Crash Investigation Sampling System (CISS) and Crash Report
Sampling System (CRSS) data. Analysis of NHTSA databases of crash tests and
collision data suggest that a Female NCAP should focus on encouraging crash
safety countermeasures in three priority areas – reducing chest injuries,
reducing lower limb injuries (especially foot and ankle injuries), and reducing
the crash severity in lower speed crashes. Based on the available literature
and the additional data analysis, proposals are offered for a Female NCAP to
address the three principal issues. These include better controls of the safety
belt and foot positioning, measuring chest and foot/ankle injury risk more
accurately, limiting brake pedal motion and limiting the initial frontal
stiffness of vehicles.
Paper No.23-0337-O
How gender preferences
for vehicle size/class influences fatality outcomes
Dainius
Dalmotas D. J. Dalmotas Consulting Inc, Canada Kennerly Digges Automotive Safety Research Institute, United States
Abstract
In recent years, the issue of gender
equity in real-world crash protection has been the focus of a great deal of
research [ 1, 2, 3, 4]. Concerns that females may be subject to elevated
risks of injury relative to their male counterparts under similar circumstances
have prompted a debate over the need for a 50th percentile female dummy. Early
automotive testing concentrated on crash test dummies with 50th percentile male
characteristics. By the mid 1990s there was general recognition of a need
to expand the family of dummies to address a wider range of the population.
Initially, the use of a smaller female dummy was prompted by the introduction
of frontal airbags and the need to put design controls in place to address
proximity issues to the airbags. However, this was quickly followed by an
appreciation of the benefits and the need for the “family of dummies" approach
in side impact testing as well as in frontal testing. More recently, the
possibility has been raised that some of the risk disparity between males and
females may not be physiological but may be related to vehicle preferences
between males and females [5]. The present study is one in a series of
investigations which seek to determine the extent to which injury outcome
differences by gender are driven by different male and female preferences for
vehicle size and class.
Thursday, April 6, 2023, | 08:30-12:30
Chair: Rikard Fredriksson, Sweden | Co-Chair: Tetsuya Niikuni, Japan
TRACK C | Room: G304
Paper No.23-0024-O
A comprehensive
evaluation of car safety evolution using model change year classifications and
traffic accident data in Japan
Kenji Kawaguchi Institute for Traffic Accident Research and
Data Analysis, Japan
Abstract
To reduce the number of traffic
accidents and injuries caused by vehicles, crash safety performances for saving
occupants and pedestrians have been improved, and also various advanced driver
assistance systems have been introduced for a wide range of vehicles in recent
years. The aim of this study was to elaborate on whether newer generations of
car models have fewer casualty accidents due to such safety evolutions from a
broader perspective. As for the classification of the cars, 411 models of
standard passenger cars including SUVs were grouped into four categories by the
year of full-model change (Mo.CY) which meant either fully remodeled or newly
introduced to the Japanese market. Specifically, the classification were as
follows; G1 (Generation 1): 2000-2002 Mo.CY, G2: 2003-2010, G3: 2011-2015, G4:
2016-2019. Regarding accident data, fatal, serious, and minor injury accidents
reported to the police in Japan between 2017 and 2020 were utilized. This
applied in common to the four Mo.CY groups. As the evaluation index, the
numbers of accidents per 100,000 vehicles registered per year were used. Then
it was assessed whether there was a difference among the groups of Mo.CY, i.e.,
whether the newer vehicle group has fewer accidents. This evaluation was
conducted from a comprehensive viewpoint including many safety systems and
crash safety performance improvements, rather than strictly assessing the
effectiveness of a specific safety system. In conclusion, analyzing accident
data for the same period of 2017 to 2020, the number of accidents for the newer
Mo.CY groups in several types of accidents were lower than that for old ones.
Regarding fatal accidents, pedestrian and single-vehicle accidents accounted
for a large percentage in the G1 group. Specifically, the analysis proved that
the number of fatal accidents per 100,000 registered vehicles has dramatically
decreased by 55% for pedestrians, and 69% for single-vehicle accidents from G1
to G4. In addition, the casualty accidents for rear-end collisions have greatly
reduced by 64% from G1 to G4. That was because the newer cars had more various
safety features and better-improved passive safety performance. It was also
clarified that the degrees of accident reduction depended on the severity of
injury and the type of accident. The method presented here, utilizing Japanese
elaborate statistical accident data, demonstrated that it was possible to
quantify the overall benefits of safety features and performances, or car
safety evolution. Therefore, it could lead to a better understanding of
real-world performance and a way to go for a safer world.
PEER REVIEW PAPER No.23-0026-O
A novel method for the
automated simulation of various vehicle collisions to estimate crash severity
Pascal Breitlauch, Christian T. Erbsmehl, Martin Urban Fraunhofer Institute for Transportation and
Infrastructure Systems IVI, Germany
Michiel van Ratingen The European New Car Assessment Programme (Euro NCAP),
Belgium Jorge L. Mallada, Niels Ferson Toyota Motor Europe NV/SA, Belgium Volker Sandner Allgemeiner Deutscher Automobil-Club (ADAC) e.V.
Technical Center, Germany
Research
Vehicle
collisions are described with the help of collision severity parameters such as
EES and the collision-based change of velocity (delta-v). These serve as an
input for injury outcome estimations through injury risk functions (IRF) or for
the virtual assessment of Active Safety Systems (ADAS) in case of a mitigated
collision. Different methods to simulate vehicle collisions are described in
the literature. Two main groups were identified: The first one delivering only
a few, partly inaccurate results obtained during a short time frame and the
other delivering detailed and accurate results but requiring high computing
time. We have developed a novel method to simulate various vehicle collisions
within a short time frame while ensuring the computation of accurate collision
severity parameters.
Methods
Three-dimensional
EES-models developed in previous research were used in this study. They
represent different passenger vehicle classes and are based on real world crash
data. In order to obtain unbiased EES values, additional crash data from crash
tests has been used in the development of these EES models. Here, they were
used to compute 2D vehicle substitute models, which are deformed during the
new, iterative method. By using fundamentals of mechanical impact calculation
and vehicle kinematics the collision is calculated. These steps are executed in
an own developed tool named impactEES, written in C++. The results obtained
were validated against measured crash test data from the European New Car
Assessment Programme (Euro NCAP) and Allgemeiner Deutscher Automobil-Club
(ADAC) Technical Center. ImpactEES combines a graphical user interface with
various single or batch crash calculations. Because of the predefined input
interface, it can be linked to any existing pre-crash-simulation software.
Results
The novel method
enables the automated computation of various car-to-car and car-to-object
collisions. The output of impactEES includes the deformation area, EES and
delta-v and the following time-dependent data for each vehicle: translational
and angular accelerations, translational and angular velocities, and the
position of the center of gravity in addition to the heading of the vehicle.
Without the need of highly sophisticated hardware, a single simulation of a
collision between two vehicles providing accurate collision severity parameters
takes only a few seconds. Based on the comparison of measured crash test data
and results obtained from impactEES the mean percentage error (MPE) and its
standard deviation (SD) were calculated for EES (MPE=-1.4%, SD=10.2%, n=13) and
delta-v (MPE=3.2%, SD=16.8%, n=22).
Discussion
The method
described above is much faster than finite element analyses and more reliable
than present momentum-based or stiffness-based simulation approaches. Currently
it is implemented in 2D only, with the intention to develop a 3D-method in the
future. Current limitations are the simplified description of indirect
deformations and the missing contact-friction mechanism.
Conclusion
The novel method allows for the 2D
computation of various car-to-car and car-to-object collisions. Using
predefined IRF makes possible the assessment of injury probabilities relative
to the change of collision severity parameters. This could be used for the
virtual assessment of injury mitigation capabilities of ADAS systems and thus
represents an important contribution to its targeted development.
Paper No.23-0039-O
Development of simulation-based
method for benefit estimation of automatic emergency braking and lane departure
warning in traffic collisions
Mitsuaki Goto, Nana
Takeuchi, Takao Matsuda, Yuichi Kitagawa Toyota Motor Corporation, Japan
Abstract
In this study, a simulation-based
method was developed for benefit estimation of Automatic Emergency Braking
(AEB) and Lane Departure Warning (LDW). The collision avoidance effect and the
injury mitigation effect of AEB and LDW were probabilistically estimated
through large-scale simulations of near-miss scenarios leading to traffic
collisions. The top nine near-miss scenarios were selected from the fatal
collision data in Japan. The simulation parameters such as vehicle speed and
its position in the lane were varied based on the statistical data to
realistically simulate various situations in the field. A total of 17,000
simulations were conducted for each with or without AEB or LDW in order to
calculate the reduction of collisions cases. For the collision cases, crash
simulations were conducted using a virtual human body model “THUMS" to predict
the fatality risk. In this study, the head injury value, HIC15, was used to
determine whether the injury level was fatal. The benefit of AEB/LDW was
estimated by multiplying their effect for each collision scenario by the
percentage of the scenarios in the total number of fatal collisions in Japan.
When neither AEB nor LDW were activated, collisions occurred in 117,031 out of
153,000 cases. When AEB or LDW was activated, collisions occurred in 48,030
cases. The collision avoidance effect by AEB or LDW was estimated to be 59.0 %.
In the collision cases, there were 415 fatal cases where AEB was not activated
while in 76 cases with AEB was activated. Based on the results, the injury
mitigation effect was estimated to be 81.5 %. The simulation results for the
top nine scenarios indicated 29.9 % for the benefit in collision avoidance and
52.4 % for the benefit in injury mitigation.
Paper No.23-0040-O
EDR reported driver
usage of crash avoidance systems for Honda vehicles
Christopher
Wiacek, Lauren Firey, Mark Mynatt National Highway Traffic Safety Administration (NHTSA),
United States
Abstract
Starting with the 2016 Model Year,
Honda Motor Co. (Honda) began to phase-in vehicles equipped with an Event Data
Recorder (EDR) that captures the status and activation of crash avoidance
technologies such as forward collision warning/automatic emergency braking and
lane departure warning/lane keeping assist. While not defined under the
National Highway Traffic Safety Administration's (NHTSA) EDR regulation 49 CFR
Part 563, Honda has elected to add these data elements. For this study, Honda
EDR data were collected from the NHTSA's 2017 – 2021 Crash Investigation
Sampling System (CISS) for vehicles equipped with this recording capability.
The data were then assessed to identify the use and activation statuses of
these crash avoidance technologies at the time of their respective crash
events. If drivers choose to disable these technologies, they will not be
afforded the potential collision avoidance and/or severity mitigation benefits
of these systems in relevant crashes. The 150 crash-involved Honda vehicles in
this study are equipped with EDRs that captured data elements related to the
function and alert status of several crash avoidance systems in the time
leading up to the crash event. The results indicate that drivers of Honda
vehicles equipped with crash avoidance systems are much more likely to have
forward collision warning/automatic emergency braking systems “On" and the lane
departure warning/lane keeping assistance systems “Off." Specifically, 99% of
drivers for this study had the forward collision warning/automatic emergency
braking systems “On" in the time leading up to the crash and thus could be
afforded the potential benefits of these systems if they were involved in a
system relevant crash situation. With respect to lane departure warning/lane keeping
assistance, 49% of the drivers had these systems “Off" at the time of the
crash, and therefore were not afforded the potential benefits of these systems
during an appropriate situation. Differences were not identified for drivers
that had the lane departure warning/lane keeping assistance “On" compared to
those that had it “Off" with respect to the driver's sex, age, and
race/ethnicity. Since data on these crash avoidance technologies are collected
on the vehicle's Bosch compatible EDR, information regarding the status for
these systems at the time of the crash event is readily accessible. This will
permit a future assessment for whether a system relevant crash event may have
occurred because the system was turned “Off." Alternatively, if the system was
turned “On," follow up assessment could be conducted for whether the system
“Engaged" and mitigated the severity of the crash. If the system was “On" but
is reported as “Not Engaged," further investigation may be warranted to
understand factors that may have prevented system activation. Vehicle level
crash avoidance system data captured in the EDR is invaluable and relevant for
assessing new field data collection, which will in turn contribute to assessing
the real-world benefits of these crash avoidance technologies.
PEER REVIEW Paper No.23-0053-O
Female crash fatality
risk relative to males for similar physical impacts
Jon Atwood,
Eun Young Noh, Matthew Craig National Highway Traffic Safety Administration (NHTSA),
United States
Research
To determine if
later-model-year vehicles with enhanced occupant protection technologies (dual
air bags, pretensioners and load limiters) reduce the disparity in fatality
risk between males and females compared to earlier vehicles.
Methods
This study uses
the Fatality Analysis Reporting System (FARS), a yearly census of fatal crashes
in the United States. Fatal crashes involving vehicles of model years 1960-2020
are included when a driver and a right front (RF) passenger aged 16-96 are
present, both have identical belt use and air bag availability, and at least
one of them dies. Logistic regression and double pair comparison are used to
estimate female fatality risk relative to males within earlier and later
model-year vehicle groups.
Results
Compared to a
peak female fatality risk relative to males for drivers in vehicle model years
1975-1979 (19 ± 5.0%), the female relative fatality risk reduced to 0.5 (±
17.5) percent for drivers in 2015-2020 model year vehicles. For RF passengers,
the peak female relative fatality risk was 27.9 (± 10.6) percent for 1960-1966
vehicle model years. This decreased to 5.3 (± 16.4) percent for 2015-2020
vehicle model years. Female fatality risk relative to males was
significantly reduced in 2010-2020 model year vehicles compared to 1960-2009
model year vehicles (-12.0 ± 5.5%). Female relative fatality risk was also
significantly reduced in vehicles with dual air bags compared to vehicles
without dual air bags, both when the occupants were belted (-11.3 ± 4.1%) and
unbelted (-6.4 ± 4.0%). When the vehicles with dual air bags and belted
occupants were restricted to only those with pretensioners and load limiters,
the reduction in female fatality risk relative to males was -15.2 (± 5.2)
percent.
Discussion
The sex disparity
in fatality risk decreased consistently over model year increments for both
drivers and RF passengers. Significant reductions were found with dual air bags
whether occupants were belted or not, suggesting that the reduction in sex
disparities in later vehicles is not due entirely to increased belt use. .
Later model year vehicles had smaller sample sizes, resulting in wider
confidence intervals and more uncertainty in risk estimates than earlier model
year vehicles.
Conclusion
Later model year vehicles with more advanced
occupant protection technologies are associated with significantly smaller
female fatality risk relative to males in crashes with similar physical
impacts. This paper provides evidence that advanced occupant protection
technologies are beneficial in tackling the problem of sex disparity in crash
fatality risk.
Paper No.23-0075-O
Representative pedestrian
collision injury risk distributions for a dense-urban US ODD using naturalistic
dash camera data
Eamon
Campolettano, John Scanlon, Trent Victor Waymo, United States
Abstract
Automated Driving Systems (ADS; SAE
levels 3 through 5 technologies) are currently being deployed in several
dense-urban operational design domains (ODDs) within the United States (US).
Within these dense-urban areas, vulnerable road users (VRU) generally comprise
the vast majority of injury and fatal collisions. One challenge with the study
of VRU collisions is a lack of crash data sources with pre-impact kinematics.
Understanding the pre-impact kinematics is a key factor in assessing the
potential injury risk for pedestrian-vehicle impacts. The purpose of this study
was to determine injury distributions for pedestrians within a dense-urban ODD
(Los Angeles, California) using data from vehicles instrumented with forward-facing
cameras and vehicle sensors. This study leveraged data from a fleet of vehicles
equipped with aftermarket, in-cabin dash cameras operating in Los Angeles,
California. From approximately 66 million miles of driving data, 42 collisions
were identified. Each vehicle was equipped with a forward-facing camera, an
accelerometer sampling at 20 Hz, and GPS. A global optimization routine was
used on the accelerometer, GPS, and video data to correct for sensor
orientation and asynchronicity in data sampling. For each event, two key video
frames were identified: the frame associated with impact and a frame associated
with key vehicle kinematics (e.g., vehicle start/stop, hard braking [> 0.2
g]). These key frames were then mapped to the processed vehicle speed kinematics
to determine vehicle speed at impact. For the events included in
this dataset, impact speeds ranged from approximately 1.6 kph (1 mph) to 65 kph
(40 mph). In most events, the front of the vehicle struck the pedestrian.
Existing pedestrian injury risk curves were then used to calculate the level of
risk associated with the reconstructed impacts, and the probability of AIS3+
injury risk was observed to vary from minimal risk (<2%) to approximately
55%. These data highlight the wide range of impact speeds and injury risk that
may occur during vehicle-pedestrian collisions. Assessing injury severity
for collisions involving VRUs is highly impactful for the continued development
of traffic safety, including ADAS, ADS, and roadway design. Using naturalistic
VRU collision data collected from dashboard cameras, a methodology for
assessing event severity by pairing accelerometer and GPS data with video to
compute impact speed was presented. This is the first known analysis of
pedestrian severity distributions using a naturalistic US database. The methods
presented in this study may be applied to larger datasets or other sensing
systems to enable further ODD-specific modeling.
Paper No.23-0086-O
The knowledge for
tomorrow's road safety bases on harmonised data - The global safety database
does its contribution
Johann Ziegler Institute for Traffic Accident Research
(VUFO), Germany Michael Düring, Michael Wagner Germany
Abstract Road
traffic accidents remain to be a leading cause of death worldwide with nearly
1.3 million fatalities each year. To develop safety systems according to
real-world challenges, harmonized information is needed. Therefore, vehicle and
road traffic safety experts are constantly looking for real-world data to
answer the open challenges and to ultimately reach the “Vision Zero". Numerous
data on road traffic accidents exist and can be split into national and
in-depth databases. The latter are characterized by a significantly lower
number of cases then the national databases but a substantially higher level of
detail and enable a microscopic view on the accident scenario. By using
in-depth databases, new safety systems may be developed and validated. The results
of analyses are extrapolated to assess the impact on road safety for a specific
country, continent or even for the whole world. However, it is not always
obvious which database is suitable for which type of development approach or
extrapolation. The Global Safety Database (GSD) solves this issue by offering
access to a one of its kind up-to-date worldwide collection of road traffic
accident statistics and database on a meta-data level. In addition to the
objective evaluation of databases by matching them to research questions, the
GSD also provides knowledge on the representativeness of each database. In
order to identify similarities and differences in road safety within the
countries, the latest publication of the Global Status Report on Road Safety from
2018 is used to develop a clustering methodology. The goal of this method is to
point out the possibilities and limitations of transferring information from
the initial countries to other areas of interest. The core of the investigation
is the clustering methodology, which generates derivatives on countries or
regions with similar road safety standards. The objective matching algorithm
within the GSD helps to find the necessary information for the qualitative
assessment of representativeness. Once the representative database within a
country is identified, the clustering results are used to determine which
countries represent the chosen database. As the clustering relies on the latest
Global Status Report from 2018 (and even partly from 2016), more recent data on
road safety is desirable to narrow the spread to a steadily growing GSD. For a
more integrated road safety approach, the GSD is also prepared to cover more
topics related to road safety e.g., infrastructure or medicine. Additionally,
an extension of the qualitative assessment of representativeness to a
quantitative is more robust. The clustering may be used to find derivations to
the initial country and to transfer the results from these to the target
countries by similarities in road traffic safety. From a global perspective,
the GSD is one essential tool to push forth the worldwide harmonisation of
traffic accident statistics and databases. Knowing what really happens on the
roads by putting together everything we know empowers the data-driven development
of safety systems and thus brings us one step closer to reach a road system
without casualties – fulfilling the Vision Zero.
Paper No.23-0093-O
Determining the
prevalence and profile of speeding in vehicle crashes using Event Data Recorders
(EDRs)
Sam Doecke, Giulio Ponte, Martin Elsegood Centre for Automotive Safety Research, University of
Adelaide, Australia
Abstract
Travelling at a speed above the speed
limit is commonly known as speeding. Prior studies examining the prevalence and
profile of speeding in Australia (and other countries) have used data from
various sources, including speed enforcement data, speed measurement surveys,
self-report studies, and naturalistic studies. Attempts have been made to
determine the prevalence of speeding in crashes using police reports, but these
have conflated inappropriate speed for the conditions with speeding. The
objective of the present study was to use data from event data recorders (EDRs)
that record pre-crash speed to determine the prevalence and profile of speeding
in crashes that occur in South Australia. Data from the Centre for Automotive
Safety Research's Event Data Recorder database (CASR-EDR) was used in the
analysis. Separate analyses were conducted for all bullet vehicles (n=319) and
for those travelling at a free, or self-selected, speed (n=160). It was found
that 27% of bullet vehicles involved in the crash sample were speeding. The
most common category of speeding was 1-5 km/h above the speed limit, but 6% of
bullet vehicles were found to be speeding by more than 20 km/h prior to their
crash. When only free speed vehicles were considered the percentage of vehicles
speeding rose to 39%. Speeding was found to be more prevalent in crashes where
the bullet vehicle was driven by a young driver, a driver with a provisional
license, or the vehicle was black, red, or grey in colour. Speeding was also
most prevalent in crashes that occurred on a weekend night, on a curve, at a
mid-block location, on a local road, in regional areas, on a wet road, in
low-speed zones, and in single vehicle crashes. These findings reinforce the
need to reduce the prevalence of speeding through means such as education,
enforcement, road design or vehicle technology. Young drivers should be a
particular focus of efforts to reduce speeding. The findings can also provide
some guidance on where enforcement activities should be further focussed.
Paper No.23-0122-O
Generating
representative test scenarios: The “Fuse for Representativity" (FUSE4Rep)
process model to collect and analyse traffic observation data
Maximilian
Bäumler, Matthias Lehmann, Günther Prokop Technische Universität Dresden, Germany
Abstract
Scenario-based testing is a pillar of
assessing the effectiveness of automated driving systems (ADSs). For data-driven
scenario-based testing, representative traffic scenarios need to describe real
road traffic situations in compressed form and, as such, cover normal driving
along with critical and accident situations originating from different data
sources. Nevertheless, in the choice of data sources, a conflict often arises
between sample quality and depth of information. Police accident data (PD)
covering accident situations, for example, represent a full survey and thus
have high sample quality but low depth of information. However, for local
video-based traffic observation (VO) data using drones and covering normal
driving and critical situations, the opposite is true. Only the fusion of both
sources of data using statistical matching can yield a representative,
meaningful database able to generate representative test scenarios. For
successful fusion, which requires as many relevant, shared features in both
data sources as possible, the following question arises: How can VO data be
collected by drones and analysed to create the maximum number of relevant,
shared features with PD? To answer that question, we used the
Find–Unify–Synthesise–Evaluation (FUSE) for Representativity (FUSE4Rep) process
model. We applied the first (“Find") and second (“Unify") step of this model to
VO data and conducted drone-based VOs at two intersections in Dresden, Germany,
to verify our results. We observed a three-way and a four-way intersection,
both without traffic signals, for more than 27 h, following a fixed sample
plan. To generate as many relevant information as possible, the drone pilots
collected 122 variables for each observation (which we published in the ListDB
Codebook) and the behavioural errors of road users, among other information.
Next, we analysed the videos for traffic conflicts, which we classified
according to the German accident type catalogue and matched with complementary
information collected by the drone pilots. Last, we assessed the crash risk for
the detected traffic conflicts using generalised extreme value (GEV) modelling.
For example, accident type 211 was predicted as happening 1.3 times per year at
the observed four-way intersection. The process ultimately facilitated the
preparation of VO data for fusion with PD. The orientation towards traffic conflicts,
the matched behavioural errors and the estimated GEV allowed creating
accident-relevant scenarios. Thus, the model applied to VO data marks an
important step towards realising a representative test scenario database and,
in turn, safe ADSs.
PEER REVIEW Paper No.23-0141-O
Evaluation of intersection
crashes using naturalistic driving data through the lens of future I-ADAS systems
Andrew
Galloway, Max Bareiss, Luke Riexinger Virginia Tech, United States Rini Sherony Toyota Collaborative Safety Research Center, United
States Takashi Hasegawa Toyota Motor Corporation, Japan
Research<
Intersection
crashes account for approximately one-in-six fatal crashes and one-in-five
crashes in the US. Intersection advanced driver assistance systems (I-ADAS) are
in development to detect imminent intersection crashes and potentially avoid
the impact with automated braking. Based on simulations of real-world crashes,
although I-ADAS could prevent many intersection crashes but could be limited by
sightline obstructions. Most studies evaluating, I-ADAS are based on
real-world, police reported crash reports, which often are unable to identify
the presence of non-contact vehicles that obstructed the view of the driver.
The purpose of this study is to use naturalistic driving data to identify challenges
for future I‑ADAS systems in straight-crossing path (SCP), left-turn
across path lateral direction (LTAP/LD), and left-turn across path opposite
direction (LTAP/OD) crash configurations.
Methods
Intersection
crashes were selected from the Second Strategic Highway Research Program
(SHRP 2) naturalistic driving study. The SHRP 2 dataset includes
front-facing, driver facing, rear facing, and a hands/feet facing video
footage in addition to the vehicle speed, steering, accelerator, and brake time-series
data. From SHRP2 data, all SCP crashes (12), LTAP/LD crashes (17), and LTAP/OD
crashes (17) were selected for in-depth analysis. The driver facing video,
front facing video, and vehicle network data were reviewed together in the
Virginia Tech Transportation Institute (VTTI) secure data enclave to understand
driver sightline obstructions, driver distractions, and initiation of driver
responses. The TTC (Time to Collision) during the precipitating event, when
either vehicle entered the intersection without the right-of-way, was computed
based on the distance to the impact point divided by the current velocity.
Because the vehicle approaches for SCP and LTAP/LD crashes are similar, the
analysis of these crash modes was combined.
Results
The median impact
speed was 18.0 mph for SCP and LTAP/LD crashes and 16.1 mph for LTAP/OD
crashes. The median TTC during the precipitating event was 1.35 s for SCP and
LTAP/LD crashes and 1.44 s for LTAP/OD crashes. For SCP crashes, the three main
sightline obstruction scenarios were slower vehicles traveling in the same
direction waiting to turn right, vehicles in the closer crossing lane, and a
parked truck. For LTAP/OD crashes, the sightline obstruction was often oncoming
vehicles in a closer lane blocking the view of another vehicle.
Discussion
The analysis of
SHRP 2 intersection crashes found that most non-distracted drivers were not
looking in the right direction to observe the collision partner. The TTC of the
precipitating event suggests that I-ADAS may be able to prevent the collision
provided the collision partner is not obstructed by other vehicles. While this
study investigated every applicable crash in SHRP 2, this is a small sample
that likely does not represent every possible intersection crash.
Conclusion
Sightline obstructions could present a
challenge for future I-ADAS to activate in SCP, LTAP/LD, and LTAP/OD crashes.
This study utilized naturalistic driving data to complete a comprehensive
analysis of intersection crashes including driver distractions, evasive maneuvers,
and sightline obstructions that can assist development of I-ADAS systems and is
not possible with police reported crash data only.
Paper No.23-0156-O
Application of a
modified integrated safety chain using in-depth crash data to identify factors
associated with serious injury crashes: A method to prioritise currently
available active safety systems and to identify new opportunities to advance
vehicle safety
Michael
Fitzharris, Mike Lenné, Sara Liu, Tandy Pok Arundell,
Sujanie Peiris, Claes Tingvall Monash University Accident Research Centre, Australia Bruce Corben Consulting, Australia Diana Bowman Arizona State University, United States Andrew Morris Loughborough University, United Kingdom
Abstract
Introduction Recognising the ambition
of Vision Zero, vehicle safety will play a critical role in reducing the number
of road users seriously injured globally. The objective of this research,
therefore, was to identify currently available and required future
countermeasures that will lead to the elimination of serious injury. To meet
this objective a systematic approach to the analysis of in-depth crash data
using case-by-case analysis linking contributing factors to safety
countermeasures was developed. Method In-depth crash investigation data
collected as part of the MUARC-TAC Enhanced Crash Investigation Study (ECIS)
was used. 400 drivers (MAIS 3+: 47%) admitted to a major trauma centre in
Victoria, Australia, were included. Data sources included: driver or
next-of-kin/family interview, ambulance and medical records, and police data.
Vehicle and scene analysis was undertaken. Crashes were reconstructed and EDR
data was accessed where available. Using a modified version of Tingvall's
Integrated Safety Chain, contributing factors and safety countermeasures across
the 10-phase crash chain were examined using a case-by-case approach.
Contributing factors were those associated with crash occurrence and injury
severity. A countermeasure library was established with each of the 278
countermeasures linked to a specific contributing factor. Countermeasures
included those focussed on the driver, passive and active vehicle safety
systems, road infrastructure and post-crash response. The efficacy and
time-horizon of each was assessed and estimated for future active safety
systems. All applicable countermeasures for each crash and injured driver were
identified; these were considered to be sensitive to the countermeasure effect.
Results Driver distraction (48.8%), sudden sickness (10.0%), drowsy driving
(24.5%), and impaired driving (19.8%) resulted in lane departure and cross-path
vehicle movements; this, combined with low proportion of driver pre-crash
braking (55%, 1.3 s) and exceeding the speed limit (27.0%) demonstrates the
need for intervening safety systems (e.g., ISA, AEB). Intervening systems to
correct lane deviations and intersection entry are also required. Discussion
The findings highlight the importance of in-depth data in establishing the use
case for existing but relatively new systems as well as the identification of
system capability limits in addressing current crash scenarios. These crash
scenarios represent development opportunities for new standalone active safety
systems. However, for full safety benefits to be realised, and to address the
full range of driver performance and impairments, next generation systems that
are fully integrated with one another are required (e.g., AEB + driver
monitoring systems, DMS). Occupant status monitoring, on-board sensors, V2I and
V2V enabled technologies linked to chassis control systems will be central to
the future safety architecture of the vehicle. The findings are relevant to
passenger vehicle crashes where at least one driver was seriously injured and
admitted to hospital. Other limitationsassociated with
the sample and data collection methods must also be considered. The analysis
method represents a powerful approach to analyse in-depth crash data and to
understand crash causation, injury occurrence and applicable countermeasures.
Adoption of this method using other datasets is recommended so that the full
range of countermeasure needs across jurisdictions and other road user groups
can be understood.
Paper No.23-0167-O
Observation-based
pedestrian scenario extraction for virtual testing
Martin Schachner, Nadezda Kirillova, Fabian Weissenbacher, Bernd Schneider, Horst
Possegger, Horst Bischof, Arno Aichberger, Zoltan Ferenc Magosi, Corina Klug TU Graz, Austria
Jan Dobberstein Mercedes-Benz AG, Germany Thomas Lich Robert Bosch GmbH, Germany Martin Kirchengast AVL List GmbH, Austria Marcus Hennecke Infineon Technologies Austria AG, Austria
Abstract
An overall reduction of
pedestrian-vehicle collisions is expected with the market penetration of
Advanced Driver Assistant System (ADAS) and autonomous driving (AD) functions.
The performance of ADAS is commonly evaluated through virtual scenario-based
testing. Hence, scenario catalogs that represent realistic pedestrian-vehicle
interactions are needed. This study shows an approach to automatically extract
pedestrian-vehicle scenarios at a selected road intersection, which was
observed with a dual-lens stationary observation system. A deep learning-based
visual perception pipeline was implemented to reconstruct road user
trajectories via state-of-the-art object detection, visual multi-object
tracking and object re-identification models. These models were trained and
fine-tuned on a manually annotated, diverse dataset, randomly sampled from
recordings over multiple weeks. All models were evaluated using common
performance metrics. Additionally, localization precision of reconstructed
trajectories was assessed using georeferenced ground truth measurements
conducted at the intersection. The visual perception pipeline was applied on
selected video data and extracted trajectories converted according to the
openSCENARIO standard, including a virtual representation of the selected road
intersection. The compiled scenarios were further simulated with the openPASS
framework. The results show that pedestrians and vehicles were tracked with
high accuracy (Multiple Object Tracking Accuracy > 83.2%) and trajectories
were reconstructed with a mean deviation of 0.9 m for pedestrians and vehicle
paths with a deviation of 0.68 (SD 0.5) m. The observation system allowed both
the obtaining of typical pathways and also speed profiles. An exemplary
reconstructed scenario was successfully resimulated in the openPASS framework.
T The described approach is promising and can be used to create new scenario
catalogs for scenario-based assessments in line with the openSCENARIO standard.
Furthermore, the view-point of the observation system allows the reconstruction
of pedestrian attributes including poses, age, or gender, which, alongside an
analysis of the recorded pathways and speed profiles with respect to
influencing factors, is a focus of ongoing research.
Paper No.23-0253-O
In-depth accident
study on D-Call Net vehicles by medical engineering collaboration
TORU KIUCHI Institute for Traffic Accident Research and
Data Analysis, Japan AYUMI SHINOHARA Ministry of Land, Infrastructure, Transport and Tourism,
Japan HIROTOSHI ISHIKAWA Helicopter Emergency Medical Service Network, Japan
Abstract
D-Call Net, which Japan was the first
country in the world to implement for practical use, is an extremely unique
advanced automatic collision notification system in which a helicopter
emergency medical service (HEMS) with a doctor and a nurse on board is requested
by a vehicle involved in a collision. Six years have passed since the start of
a pilot operation and four years since the start of a commercial operation, and
more than twenty cases have been reported in which D-Call Net has activated
HEMS and transported drivers or passengers to trauma centers. Since 2018, the
Ministry of Economy, Trade, and Industry (METI) has been supporting the
international standardization activities of the injury estimation algorithm
used in D-Call Net. Based on the newly established Japanese Industrial Standard
(JIS) D0889 [1], ISO standardization activities are continuing to develop the
technical specification under ISO TC22/SC36/WG7. On the other hand, from
FY2021, the Ministry of Land, Infrastructure, Transport and Tourism initiated
the "D-Call Net In-Depth Accident Study" in which experts in
emergency medicine and automotive engineering collaborate to establish an
accident database for developing safer vehicles, replacing the previous
"Medical Engineering Collaborative In-Depth Accident Study".
Institute for Traffic Accident Research and Data Analysis (ITARDA) has been in
charge of both ISO standardization activities and the accident studies. This
paper provides an executive summary of ITARDA's D-Call Net In-Depth Accident
Study for FY2021. A total of twenty-one collisions were investigated during the
study period, and several characteristic collisions were selected and detailed
among them. The consideration of ΔV recorded by EDR, the time saving
effect of D-Call Net and the evaluation of the algorithm according to the ISO
technical specification are also discussed.
Paper No.23-0266-O
The creation and
application of harmonized pre-crash scenarios from global traffic accident data
Henrik Liers, Marcus Petzold Verkehrsunfallforschung an der TU Dresden GmbH, Germany Harald Feifel Continental Teves AG & Co oHG, Germany Jörg Bakker Asymptotic AI, Sweden Ernst Tomasch TU Graz, Austria
Abstract
The development and test of future
Advanced Driver Assistance Systems (ADAS) and Autonomous Driving (AD) AD
functions requires sophisticated data from pre-crash scenarios. As real-world
traffic provides an infinite variety of scenarios and vehicles are usually sold
in many markets, valuable simulation datasets from several countries seem
indispensable. The paper describes how we combined the format of the Pre-Crash
Matrix (PCM) with global accident data from IGLAD. The goal was to create
harmonized pre-crash simulation files from real accidents coming from several
countries/continents and to use them exemplarily within a field-of-view
analysis for future ADAS. The basic data source is the IGLAD database. Within
the “Initiative for the Global Harmonization of Accident Data" (IGLAD) traffic
safety researchers from Europe, North America, South America, Asia, and
Australia bring together road accident data in a harmonized dataset. Each
single accident is reconstructed and contains relevant information like vehicle
data, injury severities, anthropometric data, and scaled sketches. The PCM
format describes the vehicle dynamics (trajectories) in a defined time before
the collision. It is similar to the OpenX formats and contains relevant
information about the road layout, markings, view obstacles, etc. The paper
describes the process of creating IGLAD-PCM data, including the establishment
of requirements, the harmonization of country-specific characteristics, and the
definition of quality features. In 2022, IGLAD-PCM was released for the first
time providing 200 pre-crash simulations from real accidents coming from seven
countries on three continents. The paper presents descriptive statistics (e.g.,
accident characteristics, accident configurations, injury severities) from
these cases and a comparison to the current IGLAD dataset (with approximately
9,400 accidents from 10 different countries). We provide an overview of
relevant accident situations and country-specific characteristics for different
regions of the world, e.g., US, India, China, Germany, France, Italy, etc. The
paper also highlights the benefit of PCM data as one essential source for
data-driven system development. During the concept definition of safety
systems, pre-crash trajectory data is used to derive the required functional
behavior. First, the relative positions and orientations of other traffic
opponents are the basis for defining the necessary sensor field-of-view in
given accident scenarios. Second, the speed distributions of ego and opponent
serve as key performance indicators for the vehicle actuation system. Here, a
relevant accident scenario is discussed, and relevant regional differences
analyzed. The IGLAD-PCM forms a unique global dataset of pre-crash simulations
based on reconstructed traffic accidents. Of course, case numbers are quite low
at this early stage, but will increase annually by more than 200. Using the
data can enhance the development of ADAS and AD functions and help to adjust
systems towards country-specific characteristics. We have demonstrated that the
PCM allows to harmonize pre-crash data from different countries and still can
cover regional specifics. As the PCM is an open data format, various scenario
descriptions can easily be generated, and existing development tool chains can
be supported. Thus, we believe that the PCM can serve as a standard format for
data-driven system development and simulation.
Paper No.23-0328-O
Framework for a conflict
typology including contributing factors for use in ADS safety evaluation
Kristofer
Kusano, John Scanlon, Mattias Brannstrom, Johan
Engström, Trent Victor Waymo, United States
Abstract
The aim of a successful conflict
typology (also sometimes called crash or maneuver typology) is to group
conflicts, some of which may result in a collision, into groups that have
common characteristics influencing avoidability and potential severity. A
conflict typology can be used in safety impact methodologies that analyze and
predict the potential performance of a safety countermeasure or system within a
set of defined crash modes. More generally, conflict typologies are used across
many traffic safety analyses, including those related to evaluating the safety
of an Automated Driving System (ADS). The objective of this paper was to
describe a conflict typology including contributing factors that can be used in
both Automated Driving System (ADS) and human driven vehicle safety
evaluations. The proposed typology is comprised of 5 layers: (1) conflict
partners - the types of the actors or objects involved in a conflict, (2)
conflict group - the high-level description of a conflict, (3) conflict
perspective - assigned to each actor based on their relative maneuvering, (4)
the actor role - either the initiator of some surprising action that leads to a
conflict or the responder, and (5) contributing factors - factors that in
combination contributed to the conflict initiating or non-nominal response that
caused the conflict. The main contribution of the proposed conflict typology
and contributing factors are applicable conflicts from both retrospective crash
data and near-crashes from a naturalistic driving study (NDS), and in the
future ADS conflicts. The results also highlight potential difficulties
reconciling differences in contributing factors observed in high-severity crash
data having limited contributing factor information and those contributing
factors observed in lower severity NDS data.
Matteo Rizzi The Swedish Transport Administration, Sweden
Introduction
The Ministry of Infrastructure is
responsible for road traffic safety in Sweden. However, due to the
decentralized structure in Sweden, the Ministry works with budget, targets, and
policy related issues while the operations are managed by the Swedish Transport
Administration based on the directions from the Ministry. The Administration is
responsible for the planning of the entire transport system with all modes of
transport. It is also responsible for building and maintaining roads and railroads.
The Swedish Transport Administration also has an overarching role in the
development of long-term strategies and plans for all modes of transport in the
transport system, contributing to the targets set up by the government for the
transport sector. The Transport Administration holds responsibility for
research within the fields of mobility, environment, and traffic safety.
In-depth studies of each fatal crash in road traffic are also performed. The
Transport Administration has the task of coordinating the road safety work in
Sweden in collaboration with other stakeholders.
Paper No.23-0348-O
Government Status
Report - Germany
Markus Oeser German Federal Highway Research Instutute
(BASt), Germany
Introduction
The total number of police registered
road crashes has decreased by 4 percent since 2010 – from 2.4 to 2.3 million
crashes in 2021. The number increased slightly between 2010 and 2019, with
yearly changes between -2 and 5 percent. The highest value was reached in 2019
with 2.7 million road crashes. In 2020 and 2021, during the COVID-19 pandemic,
the number of crashes steeply declined. The number of road crashes with
personal injury has decreased by more than 10 % since 2010, resulting in
258,987 crashes with personal injury in 2021. Between 2010 and 2019, the number
of personal injury crashes were relatively constant and stagnated around
300,000. This figure declined substantially in 2020 and 2021. According to
provisional data for the first nine months of 2022, the number increased by
more than 12 percent compared to the same period in 2021.
Paper No.23-0349-O
Government Status
Report - Japan
Kenji Sato Ministry of Land, Infrastructure, Transport
and Tourism of Japan (MLIT)
Introduction
Recent change of Traffic
Accidents in Japan and the Government Targets In 2021, the number of fatalities
(those who died within 24 hours) in traffic accidents in Japan was 2,636. This
is a significant decrease from the previous year, down to about one-sixth of
the 16,765 fatalities in 1970, when the number of fatalities peaked. Further,
the numbers of accidents with casualties and the number of injuries have both
decreased for 17 consecutive years since 2004, the year they were the worst. As
a further step, Japan announced in March 2021 the 11th Master Plan for Traffic
Safety (2021-2025), which sets a new goal of reducing the number of fatalities
(those who died within 24 hours) to less than 2,000 and the number of serious
injuries to less than 22,000 by 2025.
Paper No.23-0352-O
Government Status
Report - Republic of Korea
JUN HYUNGPIL Ministry of Land, Infrastructure and Transport
Introduction
The fatalities from road traffic accidents has been steadily decreased in Korea even though the number of vehicle registrations has been consistently increased over the past two decades through the Korean government’s continuous efforts and the implementation of policies. The number of motor vehicle registrations increased by 35% in 2021 to about 2,491 thousand compared to that in 2011, but the fatalities due to traffic accidents decreased by half to 2,916 for the first time in 2021 to less than 3,000. The number of traffic fatalities per 100,000 people had also continued to decline since 2014, when it fell below 10 for the first time, and was halved to 5.6 in 2020, but as of 2019, it was 1.3 times higher than the OECD averaged of 5.2(6.5 in Korea) and ranked 29th out of 36 countries, therefore, it will be still requiring steady efforts.
Chair: Jost Gail, Germany | Co-Chair: Genya Abe, Japan
Paper No.23-0164-W
Collision risk
prediction utilizing road safety mirrors at blind intersections
Ralph
Grewe Continental Teves AG & Co oHG, Germany Shintaro Ono The University of Tokyo and Fukuoka University, Japan Yoshihiro Suda The University of Tokyo, Japan Kazuya Okawa Chiba university, Japan Noriaki Itagaki Continental Automotive Corporation, Japan
Abstract Traffic
accident number in Japan has been reduced year by year by growing ADAS
technologies, revising the traffic rules, improving traffic environment.
However, to realize the Vision Zero world which is zero traffic accidents, zero
fatal accidents and zero injured seems far away currently. According to the
traffic accident statistics data in Japan, more than half of accidents are
occurring both in and around intersection areas [1]. The accident number at the
intersections without traffic light is bigger than that with traffic light and
has been seen at residential areas. To reduce the accident number at the
intersection without traffic light, road safety mirrors have been installed in
the intersection frequently [2]. In our study, using the front camera, which is
one of ADAS sensors, even if it is a scene where the front camera cannot detect
the object directly, our purpose is to reduce the collision risk by detecting
the approaching vehicle using its image in road safety mirrors. In this paper,
our collision avoidance method which consists of the 3 steps "Road safety
mirror detection", "Object detection in the road safety mirror"
and "Risk prediction" has been proposed. Especially, in road safety
mirror detection, one countermeasure for false positives (FP) has been
introduced. Our proposed method has been verified using front camera as a
feasibility study, and the effectiveness of our proposed method has been
demonstrated by experimental results on the public road. If the effectiveness
of our proposed method is proven, since road safety mirrors will be utilized,
which are a legacy infrastructure element, new investment at poor visibility
intersection can be reduced which will be one of the merits of the proposed
method. Also, the scalability of the system supporting not only Autonomous Driving
(AD) systems of level 3 and higher, but also AD level 1 and 2 such as Advanced
Driver-Assistance System (ADAS) will be an advantage.
Paper No.23-0225-W
Motorcycle state
estimation using visual-inertial odometry
Martin
Pryde, Lamri Nehaoua, Hicham Hadj-Abdelkader, Hichem Arioui Université Paris-Saclay, France
Abstract The
authors propose a visual-inertial algorithm to estimate the kinematic states of
a motorcycle traveling at high speeds along an extra-urban road. The approach
comprises the following steps: First, a monocular camera takes video of the
road ahead. Key features from sequential video frames of the road surface are
extracted using the Harris corner detector. Matching features are identified
using the Fast retina keypoint descriptor (FREAK). Next, correct the
perspective warping of the feature locations by applying inverse perspective
mapping. The motion of the transformed features is registered using the
Singular Value Decomposition (SVD) variant of the Iterative Closest Point (ICP)
algorithm. Finally, this measurement is combined with readings from inertial
navigation system using a Kalman filter to produce a filtered estimate and
correct integrator drift. The approach was validated using data from
simulations of three scenarios created in BikeSim. In the first, the motorcycle
performs a series of slaloms along a straight road at 50 km/h. In the second,
the motorcycle navigates an S-shaped bend at 80 km/h. Lastly, the motorcycle
performs a double-lane change across both lanes of a straight road at 110 km/h.
Paper No.23-0267-W
Automatic braking
systems and blind spot as examples for new approaches in type approval
regulations towards robust active safety systems
Patrick Seiniger German Federal Highway Research Instutute
(BASt), Germany
Abstract Traditional
type approval regulations typically define a small set of very precisely
defined test cases that act as an implicit requirements definition. Especially
for active safety regulations, this leads to two major problems: Firstly, the
implicit requirements are given only for a small number of operating points,
and secondly, the prescribed test cases will typically happen only on an ideal
test track. The newest type approval regulations, such as especially the new
regulation on automated emergency braking systems for heavy vehicles, define
requirements in a broader way over the whole operating range, in a certain
range of parameters (such as: for centerline offsets between -20 and +20 cm)
and leave provisions for technical services and/or market surveillance
authorities to test in different, more realistic conditions. They also require
the systems to not change strategy for cases out of the specifications (e.g.:
for higher centerline offsets). As a consequence, this shifts the specification
responsibility away from the regulator, towards the vehicle manufacturer. In
this way, there is more freedom of design while still maintaining an
appropriate level of safety. Also, the verification task is shifted towards the
technical service, who now has the responsibility to certify that the vehicle
or system matches the given overall requirements by specific test cases. The
market surveillance authority, however, has the freedom to check each and every
aspect of the system against the requirements. Market surveillance therefore
acts as a supervisor for the technical services. In the proposed paper, this
new approach is presented in detail with the examples of Regulation 131-02
(automated emergency braking for heavy vehicles) and Regulation 151 (blind spot
information systems). The new approach is described in detail with examples
from the regulation, as well as the necessary equipment to perform the test
runs in the case of Regulation 151: driving robots, robot-controlled bicycle
dummy etc. Finally, proposals will be given on how to judge whether a system
complies with the requirement to not change strategy; a topic that will become
relevant in the coming years. The combination between broad requirements, not
changing system strategy when out of the main operating range, vague defined
test cases and market surveillance as a supervisor for technical services has
the potential to make the type approval system fit for the future, and
especially for all intelligent or flexible or programmable safety systems, on
the one hand. On the other hand, technical services will have to adapt to the
new responsibility and manufacturers to the new flexibility, since the
regulation now does not exactly specify (overspecify?) a safety system, but
more specifies the expected risk balance. It will certainly take some time and
discussions until the new approach will fully unfold its potential.
Chair: Matthew Craig, United States | Co-chair: Andre Eggers, Germany
Paper No.23-0090-W
Development of simulation-based
thoracic injury probability function for elderly female occupants in side
impact
Hisaki Sugaya, Takayuki Kawabuchi, Yukou Takahashi Honda R&D Co., Ltd, Japan Craig Markusic, Skye Malcolm Honda Development & Manufacturing of America, United
States Yun Seok Kang, Amanda Agnew, John Bolte The Ohio State University, United States
Abstract Despite
the high morbidity of elderly female car occupants in near side crashes, not
many studies have been performed to predict the probability of injury to this
population. A methodology to compensate for limitations in the amount of
available biomechanical data is essential to derive an injury probability
function for elderly females in near-side crashes. This study aims to establish
a methodology to develop an injury probability function (IPF) by means of
computational impact simulations using a human body model (HBM) that also
includes variability in the material properties of human ribs. Focus was given
to the prediction of rib fractures because of their high frequency in these
near-side crash scenarios. Variation in the material properties of ribs from
the 5th percentile elderly female population were applied to a HBM developed in
a past study by applying eight different stress-strain curves. The variability
in the prediction of rib fracture was accounted for using a probabilistic
approach derived from the literature. This altered HBM was then scaled to the
size and mass of subjects used in experimental studies. The predicted thoracic
deflection was validated against both isolated lateral thoracic impacts and
side impact sled tests which included a side-airbag and a pretensioning
seatbelt. The probability of three or more rib fractures predicted by the
probabilistic approach was used to validate the altered HBM against the
previous PMHS experiments. Additional sled test simulations were conducted with
reduced energy by decreasing the impact velocity and also by varying the use of
the airbag. IPF predicting the probability of rib fractures was developed using
the logistic regression and compared between the original dataset based on the
PMHS sled tests and the modified dataset created by the additional simulations
conducted at reduced severity. Chest deflection from the experimental thoracic
impactor tests fell within the predicted range from the HBM simulations. In
addition, chest deflection from the majority of the PMHS sled experiments that
were simulated fell within the predicted range by the HBM. The probability of
3+ rib fractures was 100% for both the simulations and the experiments against
realistic lateral sled tests. The IPF developed from the modified dataset
predicted a significantly lower probability of rib fracture than that from the
original dataset. This study qualitatively evaluated the idea of predicting
injury probability for a specific population by representing the variability in
the material properties of ribs to an HBM, specifically a near-side impact load
case for 5th percentile elderly female occupants. The effect of the geometry,
such as the shape of the rib cage and rib thickness, was not reproduced in this
study. The method used to derive the IPFs could also be done for other load
cases and populations.
Paper No.23-0218-W
Probability functional
evaluation of chest injury based on rib strain of human body model in frontal
collision
Yoshiki Takahira,Shizue Katsumata, Takeshi Yamamoto, Mitsutoshi Masuda Toyota Motor Corporation, Japan
Abstract This
study examined the influence of chest restraint force on the chest injury
probability of the human body model (HBM) in frontal collision. Total Human
Model for Safety (THUMS) Version 4.1 AM50 was seated in the driver's seat of a
finite element (FE) model represented a prototype midsize vehicle, and frontal
collision simulations were performed. The probability of three or more rib
fractures from 20YO to 80YO were predicted from simulated THUMS rib strain
based on prior work. The probability increased with age and showed a tendency
to rise sharply beginning around the 60YO in particular. The trend was shown to
be similar to the probability predicted statistically from the NASS-CDS field
accident data. Furthermore, a collision simulation was also conducted in which
the restraint balance between the seatbelt and airbag was changed while keeping
the same amount of forward excursion of the occupant. As a result, it was found
that the probability of rib fracture was reduced by the combination of reducing
the seatbelt force and increasing the initial restraint force of the airbag
compared to a base specification. This was due to the improved ride-down
efficiency and reduced seatbelt contact force, which reduced the strain on the
upper ribs on the path of seatbelt.
Paper No.23-0261-W
Methodology to predict
strain of bridging vein due to rotation of head
Yukou Takahashi,Toshiyuki Yanaoka Honda R&D Co., Ltd, Japan
Abstract The
brain stem can be damaged by the herniation of the brain tissue, potentially
leading to fatality. Mass lesion could lead to fatality due to brain stem
herniation, necessitating the prediction of the strain of the bridging veins
(BVs). A number of trabecula forming a web-like structure of the sub-arachnoid
space (SAS) may allow the assumption that the strain of the BVs correlates with
that of the SAS. The objective of this study is to investigate the predictive
capability of the strain in both the brain parenchyma (BP) and the SAS using a
simplified physical model based on the CIBIC (Convolution of Impulse Response
for Brain Injury Criterion) criterion proposed by the authors. A viscoelastic
model consisting of a series of two sets of standard linear solids (SLSs) used
in the CIBIC criterion (extended version of CIBIC; e:CIBIC) was developed to
represent both the BP and the SAS. The Global Human Body Models Consortium
(GHBMC) head/brain model was used to obtain the target response of the maximum
principal strain (MPS) in the BP and the SAS. Three angular acceleration time
histories to be used to optimize model parameters were determined by combining
twenty sine waves with the frequency ranging 10-200 Hz. The optimization of the
spring and damping coefficients was performed by maximizing the CORA
(CORrelation and Analysis) score for the time histories of the MPS in the BP
and the SAS obtained from the GHBMC model. The optimized e:CIBIC was further
assessed against a total of 256 sets of head rotational acceleration time
histories obtained from frontal and side impacts and pedestrian impacts. The
assessment was performed for the coefficient of determination of the
correlation of the peak MPS with the GHBMC model along with the average value
of the CORA score with the strain in both the BP and the SAS. The two-assessment
metrics were also compared against the original CIBIC criterion for the brain
strain to clarify improved prediction. The results of the performance
assessment using the two metrics showed that e:CIBIC is capable of simulating
the MPS in the BP with an accuracy similar to the original CIBIC. It was also
found that the predictive capability of e:CIBIC for the MPS in the SAS is
higher than that of the original CIBIC for the MPS in the BP. This study
revealed that e:CIBIC with the two sets of the SLS in series is capable of
predicting the strain in both the SAS and the BP simultaneously. The results
obtained in this study is dependent upon the validity of the head/brain FE
model used. The relationship between the strain of the SAS and the probability
of BV failure needs to be further investigated.
Paper No.23-0262-W
Effect of seat belt
use and airbags deployment on clinical outcomes in road traffic injury patients
Jong Hee Kim,Gwan Jin
Park, In Chan Shin, Seung Min Yong, Young Min Kim, Hyun Seok Chai,
Sang Chul Kim, Hoon Kim, Suk Woo Lee Chungbuk National University Hospital, Korea, Republic of
Abstract
Objective:
Seat belts and airbags are safety devices designed to prevent road traffic
injuries (RTI). They reduce fatal outcomes in patients with RTI. This study
aimed to compare their effectiveness on the clinical outcomes of injured
patients with RTI. Methods and Data sources: A multicenter cross-sectional
study was conducted using the Emergency Department-based Injury In-depth
Surveillance (EDIIS) registry between Jan 2011 and Dec 2020. All patients who
sustained RTI in a vehicle with fewer than 10 seats were eligible. The target
population was categorized into four groups: seat belt use and airbag
deployment, seat belt uses only, airbag deployment only, and non-use. The
primary outcome was intracranial injury. The secondary and tertiary outcomes
were intensive care unit (ICU) admission and in-hospital mortality. The
adjusted odds ratios (AORs) (95% confidence intervals [Cis]) of the safety
device for related outcomes were calculated. Results: Among 82,262 patients,
13,929 (16.9%) were classified as seatbelt and airbag deployment; 47,123
(57.4%) as seatbelt use only; 1,820 (2.2%) as airbag deployment only; and
19,300 (23.5%) as the non-use group. Compared to the non-use group, AORs (95%
CIs) for intracranial injury were 0.49 (0.42-0.56) in the seat belt use and
airbag deployment groups, 0.39 (0.35-0.44) in the seat belt use only group, and
1.34 (1.08-1.67) in the airbag deployment only group. For in-hospital mortality,
AORs were 0.29 (0.22-0.36) in the seat belt use and airbag deployment groups,
0.17 (0.14-0.21) in the seat belt use only group, and 1.74 (1.30-2.32) in the
airbag deployment only group. Conclusion: Seat belt use had a significant
preventive effect on intracranial injury and in-hospital mortality. The airbag
deployment only group had worse outcomes. Public efforts to increase the proper
use of safety devices are needed to reduce the RTI burden.
Chair: Thomas Belcher, Australia | Co-chair: Cecilia Sunnevång
Paper No.23-0220-W
A process to qualify a
dummy model for the use in a virtual testing application
Michael Putzer PDB - Partnership for Dummy Technology and
Biomechanics, Germany Frank Njilie Adamou Altair Engineering Inc., France Fuchun Zhu Humanetics Innovative Solutions, Inc., United States Matthias Walz Mercedes-Benz Group AG, Germany Jakub Galazka Toyota Motor Europe NV/SA, Belgium
Abstract Finite
element models of crash test dummies are extensively used throughout the
development process of new cars. Each model has to go through various
validation steps to meet user- or manufacturer-defined quality requirements.
However, there is no standardized process established to qualify a model for a
specific virtual testing application in general. A consumer rating organization
intends to include virtual testing in their rating protocol. The pilot use case
will be a far side impact using the WorldSID 50th. Virtual testing requires
validated models of environment, restraint systems, and dummy but there is no
standard available to determine the level of validation. This paper presents
the work of an ACEA working group that developed a process to qualify WorldSID
50th dummy models for the use in a far side virtual testing application. The
validation processes including validation data of different WorldSID 50th
models were reviewed. A multi-level procedure covers general properties,
fundamental dynamic behaviour, and application specific loadings. The
assessment is based on pass/fail criteria as well as on objective rating
methods. For final confirmation of the methodology four state of the art models
and an artificially degraded model were used. The designed process comprises
three levels that need to be passed. It is only valid for applications that
have very similar load levels and load patterns (reference application). The
first level checks general properties of the model against the hardware. It
includes drawing conformity, external dimensions, range of motion of joints and
mass properties. The second level checks the fundamental dynamic behaviour of
the model. The model must pass all qualification requirements. The third level
is derived from the reference application. It checks the performance of the
most important components (body segments) and of the whole dummy. The boundary
conditions of these checks are derived from the reference application. The
relevant dummy signals are assessed by using the objective rating method
defined in ISO/TS 18571 [3]. All signal scores are weighted and combined to a
total rating. The assessed responses cover kinematics as well as internal
loads. The model must achieve a minimum total rating score to pass this third
level. A model is validated or qualified for the virtual testing application if
all three levels are passed successfully. The far side application requires a
dynamic assessment of lumbar spine and neck. An additional sled test with a
simplified vehicle environment evaluates the performance of the whole dummy
model. The process offers the opportunity to assess the level of validation
based on objective criteria. It can distinguish between different levels of
validation. The process provides a method to qualify models for use in virtual
testing based on objective parameters and rating schemes. It might become a
standardized method to qualify the WorldSID 50th model as one component to
introduce virtual testing.
Chairperson: Lori Summers, United States | Co-chair: Philippe Vezin, France
Paper No.23-0009-W
Validation of safety
of the intended functionality for autonomous driving systems
Jihas Khan,Chandni Sapna Vijay Tata Elxsi, India
Abstract International
organisation for standardisation (ISO) safety of the intended functionality
(SOTIF) is a relatively new standard that explains the verification mechanism
for handling the intended functionality of a system as well as reasonable
misuse of the system. It is required to practically implement the ISO SOTIF
based validation of advanced driver assistance system (ADAS) and autonomous
driving. The objective of this paper is to explain the strategy of virtual
simulation and synthetic scenario creation for the validation of ISO SOTIF by
taking intelligent speed assistance (ISA) as an example. ISO SOTIF
suggested process flow is taken as a reference for the derivation of test
strategy by keeping technical and functional safety requirements as the
foundation for testing. Hazard identification and risk evaluation are
implemented by following the defined standard procedure. Virtual simulation
tools are utilized for ISO SOTIF synthetic scenario creation. A scenario
elicitation approach is proposed with elaborate examples. A tree diagram with
all possible and relevant static and dynamic actors is used for generating
scenarios. 'One' or 'two-liner' pseudo scenarios are created first, which are
then extended to full-fledged scenario details. These detailed scenarios are
then implemented in a virtual simulation tool. The algorithm under test is
exposed to these ISO SOTIF scenarios in a SIL / MIL / HIL environment, to
evaluate how the system responds to such corner cases. It is also possible to generate
additional ISO SOTIF scenarios from the input requirement specification. A few
scenarios involving varying environmental conditions and hazard simulation
instances are showcased in the paper. The paper explains through real-world
examples, on how to do ISO SOTIF based testing for autonomous driving systems.
A novel and implementation independent ISO SOTIF validation strategy is
proposed in this paper. Use cases of residual risks deemed acceptable are also
explained in the paper intuitively. ISO SOTIF validation strategy is studied
with intuitive examples.
Paper No.23-0019-W
Identifying effective
STPA control structures to characterize SOTIF areas 1,2,3, and 4 in automated vehicles
Xuezhu Yang, Zhongju
Di China FAW Group Co.,Ltd., People's Republic of China Juan Pimentel, Gregory Gruska OMNEX Inc., United States Rolf Johansson OMNEX Inc., Sweden Ruoyu Xu, Fu Xu OMNEX(Shanghai) Co. LTD, People's Republic of China
Abstract Developing
and automated driving system (ADS) for an automated vehicle with a sufficient
level of safety has turned out to be a much more difficult problem than
anticipated by the industry. The challenges are multiple, for example the
existence of a very large number of critical scenarios that would require testing
vehicles for billions of miles to guarantee safety. In this paper we propose
using System Theoretic Process Analysis, STPA, to characterize SOTIF areas 1,
2, 3, and 4 for SAE automation levels 3 and 4. A key challenge of STPA is the
identification of an appropriate dynamic control structure that is efficient
for the purpose at hand. We propose a control structure built around the
decision hierarchy of strategical, tactical, and operational decisions, used to
structure an ADS including its relations to the user, the environment, and all
other traffic actors. More specifically, we show how an analysis based on this
control structures at the strategic, tactical, and operational levels can be
used to identify safe and unsafe control actions (UCAs) in known scenarios.
Paper No.23-0222-W
New assessment and
testing methodology for vehicle type approval
Carlos Lujan,Oriol Flix Applus+ IDIADA, Spain
Abstract In
the context of a deep transformation in the automotive technology, specially
with the wide introduction of ADAS functions and the first commercially
available vehicle with automated functions, the classic type-approval
procedures have been challenged and new methodologies are required. This paper
describes the actions being carried out at different levels in order to tackle
such challenge, as well as the main future trends with regards to the new
assessment and testing methodologies for the type-approval of vehicles and
their systems.
Paper No.23-0223-W
Cyber Security
regulation – Practical application from a technical service point of view
Oriol Flix,Carlos Lujan Applus+ IDIADA, Spain
Abstract It
is widely known that the future of vehicles is a progressive evolution from
conventional vehicles to fully autonomous/connected vehicles able to deal with
all the situations on the road. This process starts with new ADAS (Advanced
Driver Assistance Systems) functions that are gradually taking the control of
the vehicle, in controlled situations, over the driver. Based on these new
technologies, and always from the safety point of view, the European Union
introduced the new General Safety Regulation. This regulation introduces
advanced safety requirements that will become mandatory from 2022 for new vehicle
types. One of the regulations that will cause a major impact on manufacturer's
internal procedures, but also on the way in which Approval Authorities and
Technical Services assess the system, is the regulation on Cyber Security, UN
R155, that requires a new approach on how to validate and certify a system
Paper No.23-0294-W
Infrastructure
connectivity to improve automated driving safety and information quality
Ilkka Kotilainen, Risto Kulmala Traficon Ltd, Finland Hironao Kawashima Keio University, Japan Sven Maerivoet Transport & Mobility Leuven, Belgium Siddartha Khastgir WMG, University of Warwick, UK, United Kingdom Steven Shladover University of California, Berkeley, United States Jaap Vreeswijk, Tom Alkim, Anton Wijbenga MAP traffic management Ltd, Netherlands
Abstract All
actors in road transport share and aim for the same mutual goal of safe, clean,
and efficient Connected and Automated Driving (CAD). The aim of the research
was to study how infrastructure connectivity improves Automated Vehicle (AV)
safety in three selected motorway environment use cases of traffic jam, adverse
weather and static/dynamic road works as well as quality indicators and
requirements for the communication. Information priority with safety
criticality in mind was assessed for the three actors of road works or (winter)
maintenance operator, traffic manager and AV or Automated Driving System (ADS)
developer. The results present Operational Domain Design (ODD) and local
condition attributes information priority recommendations, ADS developers trust
issues when using information via infrastructure communication, information
quality recommendations as well as quality monitoring and management methods.
Paper No.23-0320-W
Transfer of
reconstructed real-world accident data into scenario catalogues for the
development and test of ADAS and ADS
Marcus
Petzold, Thomas Unger, Henrik Liers Verkehrsunfallforschung an der TU Dresden
GmbH, Germany
Abstract The
development and test of ADAS and Automated Driving Systems (ADS) require
appropriate scenario data. To ensure the correct functionality and functional
safety of such systems, an incredible amount of scenarios is necessary,
containing normal, critical, and accident situations. These scenarios are
usually used for virtual simulations. However, selected scenarios should be
also physically tested on proving grounds. We developed a method to extract and
describe maneuver-based and parameterized scenario catalogues for development
and test of ADAS and ADS. We used real accident data from GIDAS (German
In-Depth Accident Study). The focus was on car accidents in urban areas as the
complexity in urban traffic is much higher than on highways (heterogeneous
infrastructure, large variety of road users and behavior). At first, we
clustered the (weighted) GIDAS accidents into different scenario groups. Then,
we identified relevant parameters that are necessary for the description of the
static and dynamic content of scenarios. The static content was extracted
within the “environment analysis". With this, the scenarios can be
parameterized in terms of weather and lighting conditions, road layout (e.g.,
number of lanes, road width etc.). For the “dynamic analysis" we additionally
used the GIDAS-PCM, containing reconstructed maneuvers, time- and
location-resolved trajectories, accident sequences. Here, we generated
statistical descriptions about speeds, trajectories, braking or steering
maneuvers. Finally, some concrete example scenarios have been transferred to
IPG CarMaker and OpenDRIVE / OpenSCENARIO files. With the developed method it
is possible to transfer thousands of single traffic events and/or accidents
with concrete characteristics into generic (test) scenarios. Within the
project, scenario groups have been created using a maneuver-based approach.
There are currently four main categories (following in one lane, crossing
scenarios, turning scenarios, and lane change) which are further divided into
sub-maneuver groups. The created parameter sets per scenario group contain
several static and dynamic parameters. These distributions can be used by
system engineers for virtual simulation runs (e.g., with randomly varied
scenarios) but also by test engineers to parameterize physical tests. The
approach was already tested with partners with demonstrations in physical
tests. The implementation in concrete formats (IPG CarMaker, OpenX) showed that
an automated transfer is not possible at the moment due to the complexity and
multitude of implementation options. The developed method works for accident
data out of GIDAS and was already tested in physical tests. However, the method
was not yet applied to normal/critical situations, but this should also work
with the presented static and dynamic parameter sets. Another limitation is the
lack of automatic data transfer from the PCM format into the open ASAM
standards (OpenX). As scenario catalogues are essential for virtual simulations
as well as for physical tests of ADAS and AD functions the presented method
helps to provide appropriate scenario data out of real-world accidents. The big
advantage is that the created parameter sets and scenarios base on reconstructed
accident data and can be used independently from certain software solution or
format.
Chair: Kevin Moorhouse, United States | Co-Chair: Atsuhiro Konosu, Japan
Paper No.23-0199-W
THOR M50 and F05
submarining probability
Xavier
Trosseille, Philippe Petit LAB PSA Renault, France Pascal Baudrit CEESAR, France
Abstract During
a crash test, submarining detection of the dummy is possible, either from film
analysis or from measurements taken on the pelvis, especially when a force drop
is observed in the Antero Superior Iliac Spine (ASIS). In the absence of
submarining, it can sometimes be difficult to know if submarining was close to
occur or if the configuration remained in a safe zone. In other words, was the
situation really safe and stable with respect to submarining, or may small
variations in test conditions lead to dramatic consequences? The objective of
this study, carried out within the framework of the ABISUP project (Abdominal
Injury and Submarining Prediction) was to determine a criterion for evaluating
the submarining risk of occurrence for the THOR-M50 and THOR-F05 dummies. The
ABISUP consortium was composed of Toyota Motor Europe (TME), University Gustave
Eiffel (former IFSTTAR), University Claude Bernard Lyon 1, Transpolis,
Faurecia, Humanetics, CEESAR, NHTSA and LAB PSA Renault (coordinator). The ASIS
transducers allow the measurement of the forces applied on the iliac wings in
the antero-posterior direction (Fx) as well as the moments along the
medio-lateral axis (My). This latter provides an indication of the position of
the belt relative to the ASIS. To establish more precisely the point of
application of the force, a lever arm can be calculated by dividing the moment
by the force. When the value of this lever arm approaches the upper edge of the
sensor, the risk of submarining increases significantly. The lever arm,
identified as a submarining criterion, was calculated for a whole series of
sled tests carried out with the THOR-M50 and THOR-F05 dummies and compared with
the occurrence of submarining. Risk curves were constructed using the lever
arm. This paper provides a list of the tests performed, together with the
maximum lever arm values calculated at the time of submarining. Risk curves are
provided for both dummies. Very few cases were identified where the criterion
was decreasing prior to the occurrence of submarining. Furthermore, the range
of values obtained during submarining indicated that influential factors were
not accounted for. These two limitations suggested that further investigations
are needed, although the proposed criterion could give a first indication of
the risk of submarining. A submarining criterion associated with risk of occurrence
curves was proposed for the THOR-M50 ABISUP and THOR-F05 dummies. This
criterion provides an aid to the analysis of dummy tests, which justifies its
publication.
Chair: Peter Burns, Canada |
Co-chair: Stacy Balk, United States
Paper No.23-0061-W
Using accident
location and interpretable risk to fine tune advanced rider assistance systems
for motorcyclists
Andreas Hula,Klemens
Schwieger, Peter Saleh Austrian Institute of Technology, Austria
Abstract Motorcycle
riding is a popular activity among riders of all ages and the number of
motorcyclists is still increasing, despite safety issues being tricky to
resolve for this mode of transport. Motorcycle rides constitute a type of
vulnerable road user (VRU) since accidents tend to have more severe
consequences for them due to the lack of physical protection for riders
compared to passengers in passenger cars. Since this is a consequence of the
very nature of the vehicle (being less heavy and more dynamic to move)
potential safety interventions for motorcyclists need to be based on predictive
indicators for unsafe situations and aim to avoid crashes altogether. This
paper presents the results of ongoing work to improve motorcycle safety by
finding causally interpretable risk characteristics based on accident data and
motorcycle riding dynamics collected from test rides by individual riders.
Dynamics data at known accident spots and representative data for individual
rider-typical motions is associated to the type of historical accident in order
to produce an estimate not only of risky areas and maneuvers, but also to
associate types of riding dynamics that put the driver at risk. The relation to
potential causes is essential for the inclusion of the resulting risk warnings
in the activation of an Advanced Rider-Assistance System (ARAS), in order to
produce a tailor-made response to the individual.
Paper No.23-0111-W
Spatial sound
assistance system for 360-degree hazard awareness and safe driving
Masaki Maruyama,Junichi Sakamoto Honda R&D Co., Ltd, Japan
Abstract In
everyday driving situations, potential sources of collisions can appear from
any direction around the driver. Driver assistance systems have been highly
desired to assist driver's hazard awareness from all directions in order to
eliminate any kinds of traffic accident fatalities. The current study addressed
whether simulated spatial sounds providing directional and hazard attribute
cues for potential collisions can facilitate drivers' identification of traffic
hazards and reduce collision incidence in the front and rear spaces.
Forty-eight participants took part in our simulator experiment. We used a
driving simulator (Honda Driving Simulator Type-DB Model S) to present them
various traffic scenes with respect to the hazardous direction and recorded their
driving operations. Participants' gaze directions were also recorded with an
eye tracker implemented on the simulator. To provide a directional cue of
hazardous traffic participants, we presented spatial sounds on the directions
of hazard participants, using two speakers implemented in a driver's seat. To
provide an attribute cue for hazardous objects, we classified the traffic
participants into four categories (vehicles, motorcycles, bicycles,
pedestrians) and presented a corresponding imitative sound for each hazard
object. Presentations of monaural sound without directional cue and signal
sound without attribute cue were also used as a comparison basis. The current
study observed a decrease in collision frequency and a significant reduction of
onset time for pushing down the brake pedal for frontal hazard when spatialized
signal sounds were presented compared with no HMI condition. A decrease in
collision frequency with gazed hazards in the rear space was also observed when
spatialized imitative and signal sound were presented relative to no HMI
condition. The results lend to support our hypothesis that the directional cue
can be effective for safer driving behaviors. On the other hand, improvements
were not obtained when attribute cues were presented for both behavioral
responses or the collision frequency. Significant facilitations were found in
gaze responses and decelerate operations especially for rear hazards, but they
did not result in a reduction of collision frequency. Although the well-known
front-rear ambiguity was confirmed in stationary sound localization, the
current study observed the effectiveness of directional cue in reducing the
collision frequency. It is possible that movements of spatial sound sources
with hazard traffic participants could improve the resolution of front-rear
sound localization. The influence of front-rear ambiguity might have also been
reduced by extended spatial attention from the rear to the front under the
auditory directional cue towards the rear space. The attribute cue did not
provide any effective improvements in the current study. However, we believe
that in certain traffic situations where the type of hazards involved could
represent more important information to the driver, the effects of attribute
cue could reveal a potentially larger impact. Our observations of the effective
assistance of directional cue in spatial sound provide important references in
terms of human factors for considering informative HMI that facilitates hazard
awareness from all directions and help safer driving behaviors.
Paper No.23-0196-W
Novel interfaces that
enhance a driver's ability to perceive forward collision risks
Takahiro Matsuoka,Tsuyoshi Nojiri Honda R&D Co., Ltd, Japan Vanessa Krüger Honda R&D Europe GmbH, Germany Matti Krüger Honda Research Institute Europe GmbH, Germany
Abstract Forward
Collision Warning (FCW) systems that alert a driver about the risk of rear-end
collisions can contribute to a reduction of traffic accidents caused by human
errors. Typically, FCWs create alerts that appear late when the risk is already
high and are of binary nature, i.e., either in an alerting state during high
risk or not producing any alert at lower risks. The choice at what risk level
to start alerting in a binary manner is subject to a tradeoff between how much
time an alert gives the driver to react and how necessary the alert appears to
the driver. Our goal is to circumvent this limitation of classical binary FCWs
to allow drivers to perceive developing risks early and in an intuitive manner
and, accordingly, better avert developing risks with foresight. To that end, we
propose a new system that assesses potentially hazardous situations in real
time and continuously outputs a signal that alters its strength depending on
the risk level. Here we report a study on the effect of variations of the
proposed system on driving behavior and user acceptance. The experiment was
carried out in a driving simulator equipped with prototypes of visual,
auditory, and tactile human-machine interfaces (HMIs). The participants
performed driving tasks in two different driving scenarios. The subjective
ratings of system acceptance were assessed with questionnaires on two
dimensions, a usefulness scale, and an affective satisfaction scale. The
results indicate that, compared to an existing FCW system, all HMIs reduced
driver reaction times and the visual HMI showed positive average scores of both
usefulness and satisfaction in the driving scenario with high and medium
collision risk. On the other hand, there was no HMI that achieved a good
balance between the effect on driving safety and system acceptance in the
scenario with lower criticality. These results suggest that the proposed
notification system can improve driving safety and be perceived as subjectively
acceptable in situations with high and medium collision risk despite the early
signal. This makes it a promising approach for circumventing the tradeoff
between notification timing and risk perception. To address system effects on
driving safety in situations with lower risk, further development iterations
and long-term evaluations in a variety of traffic situations may be required.
Paper No.23-0226-W
Monitoring system of
driver's health condition to prevent traffic collision caused by health
condition risks and cognitive decline
Satoru Shinkawa,Hideki Sakai, Hiroshi Ono, Masahiro Kimura Honda R&D Co., Ltd, Japan Keisuke Nakamura Honda Research Institute Japan, Japan Noriyuki Kimura, Teruaki Masuda, Etsuro
Matsubara Oita University, Japan Atsuhito Nakamichi, Shirou Yano, Takao
Fujino Usuki-City Medical Association, Japan Emiko Segawa, Takuma Sato, Yoshitaka
Nakamura, Kazuya Nagaoka, Ken Aoshima Eisai Co., Ltd., Japan Shigenobu Mitsuzawa Honda R&D Co., Ltd, Japan
Abstract Driving
risks for elderly drivers are known to be associated with age-related diseases
and cognitive decline. Furthermore, daily physical conditions such as
drowsiness and fatigue also affect cognitive function and driving behavior.
Therefore, in order to prevent traffic accidents involving elderly drivers, it
is important to provide personal driver support that takes into consideration
the effects of daily physical conditions. In this study, we explored the
feasibility of a monitoring system utilizing daily physical condition data that
can be assessed by wearable devices on elderly subjects. Focusing on the sleep
characteristics that affect the physical condition, we found the relationship
between attention function and driving behavior. As a result of the attention
function evaluation by the Attention Network Test, irregular sleep time was
associated with greater variation in attention function, suggesting that people
with irregular sleep time had more unstable attention function. In addition, as
a result of the driving behavior evaluation by the Driving Simulator Test,
greater variation of the attention function was associated with the larger
steering entropy and maximum acceleration of the car. These results suggest
that instability of the attention function may cause the rough driving.
Combined with the results of relationship between variability of sleep time and
attention function, these results suggest that people with irregular sleep time
are more likely to engage in rough steering and pedal operation, which may lead
to sudden steering and acceleration that can cause accidents. It is also known
that elderly people have problems in falling asleep and maintaining sleep than
younger people. In order to eliminate traffic accidents involving elderly
drivers, a support system that incorporates information on sleep habits will
become more important. In recent years, the use of wearable devices has made it
possible to objectively acquire daily activity and sleep data, and it is
expected to utilize a wider range of daily activity data. In the future, we are
planning to acquire actual vehicle driving data to understand the relationship
between physical condition and driving behavior in more detail.
Paper No.23-0229-W
The impact on driving
performance from graded cognitive load with visuo-spatial and phonological
processing of visual and auditory input
Abstract The
majority of human factors in traffic accidents are the result of cognitive
error. Errors of cognition are produced by the relationship of the cognitive
load of the traffic environment and vehicle interior environment with the
driver's information processing. The cognitive load while driving is made up of
the loads from the sense organs of sight and of hearing. The resources used for
processing of visuo-spatial information and phonological information are
independent, and it has been proposed that each processing resource has its
capacity. It has been reported in previous research that when the cognitive
load increases, driving becomes unstable. On the other hand, it has been
reported in other research that when the cognitive load becomes high, driving
becomes stable. Considering that cognitive load has been reported as an
influence that both increases and decreases performance, it is conceivable that
performance varies with the type and magnitude of the cognitive load from each
category of information, and that a moderate degree of load exists under which
performance reaches its highest level. For this paper, a driving simulator was
used to study the influence on driving performance caused by graded cognitive
load from the visuo-spatial process and phonological process of input from the
sense of sight and sense of hearing. In testing, drivers drove on a course with
a series of gentle curves while responding to n-back tasks that use
visual/visuo-spatial process and auditory/phonological process. The result was
that in the case of n-back tasks using visual/visuo-spatial processing, driving
performance was diminished as the difficulty of the n-back task increased.
However, in the case of n-back tasks using auditory/phonological processing,
driving performance did not change when the difficulty of the n-back task increased.
Also, although the load under which performance reaches its highest level was
not determined, it was confirmed that auditory n-back tasks do have loads under
which performance tends not to change. This is thought to be because the
visual/visuo-spatial process used in driving and other information processes
tend not to influence each other, while the same information processes did
interfere with each other. The conclusion is that, in order to maintain stable
driving performance, it can be considered important that the cognitive load on
the driver does not interfere with the processing of visual/visuo-spatial
information while driving.
Paper No.23-0279-W
Non-invasive blood
alcohol detection using near infrared spectroscopy and chemometric techniques
Salvatore Brauer,Gary Ritchie, Len Cech Joyson Safety Systems, United States Emil Ciurczak Doramaxx Consulting, United States John Coates John Coates Consulting, United States
Abstract An
updated research, development, and manufacturing of a novel passive
contact-based Near-Infrared Alcohol Sensor (NIR-AS) for non-invasively
measuring Blood Alcohol Concentration (BAC) in human subjects and thus,
provides potential for application in support of the new US Infrastructure
Investment and Jobs Act bill, section 24220, signed into law on 11/15/2021 once
it is enforced. Alcohol-impaired driving remains a global problem. According to
the most recent published report in 2020, U.S. motor vehicle crashes,
alcohol-impaired fatalities represent over 30% of the total fatalities; a 14%
increase over 2019 and a 29% increase relative to Vehicle Miles Traveled (VMT).
The Infrastructure Investment and Jobs Act bill, section 24220, cites
statistics on the societal and human costs of alcohol impaired driving and
specified intent to make BAC sensors standard equipment in all new U.S. cars in
the future. The NIR-AS design and process for analyzing performance in
quantifying BAC builds on the R&D carried out in support of the Driver
Alcohol Detection System for Safety (DADSS). The published research from DADSS
provides valuable technical guidance and performance targets for BAC sensing in
motor vehicles. Blood testing is the established gold standard for measuring driver
BAC. Although blood testing is the most accurate reference for comparison
against NIR-AS (or any new BAC sensor), it is highly invasive, time consuming,
and cost prohibitive. Breathalyzers are well established sensors for estimating
BAC, however, they also have performance limitations in practical, real-life
conditions. Even so, based on published research, including DADSS,
breathalyzers can provide an appropriate surrogate reference under controlled
clinical and analysis conditions, for analyzing the performance of any new BAC
sensor. The NIR-AS sensor described in this paper targets the passive detection
performance requirements specified by DADSS. An alcohol dosing Design of
Experiments (DOE) was carried out using a set of Near Infrared Alcohol Sensor
(NIR-AS) prototypes with human subjects using a repeat low level alcohol dosing
protocol. BAC reference data was also collected using several law enforcement
grade and commercial breath analyzers. NIR-AS spectra were processed and
analyzed using commercially available and proprietary software. The DOE
resultant data was analyzed using commercially available software packages to
produce chemometric models. The paper presents model performance statistics
including root mean square standard error of calibration (RMSEC), root mean
square standard error of prediction (RMSEP), and square of the correlation
coefficient, R2, for the NIR-AS calibration. A global model employing multiple
sensors was tested across the same DOE and performance statistics are presented.
Using NIR-AS, it is shown that BAC can be measured at varying concentrations of
alcohol within the human body, including low alcohol dosing levels. Further
improvements on the NIR-AS design and function will also be presented. Based on
our results, there is significant correlation between BAC breathalyzer and NIR
measurements at low dosing levels. The results demonstrate a high correlation
between NIR-AS spectra and reference breathalyzers and achieve low RMSEP,
RMSEC, and RMSECV. NIR-AS, with continued development, can be a potential tool
for assessing driver alcohol impairment in support of ADAS and/or ADS
countermeasures.
Paper No.23-0291-W
Driver alcohol
Detection System for Safety (DADSS) – risk-based approach to alcohol sensing
outcomes modeling/Human Subject Testing (HST) /Human Subject Driving
(HSD)/Field Operational Testing (FOT)
Michael
Willis Jr., Tim Allen,Abdulatif Zaouk, Kelly Ozdemir, Kianna Pirooz, Maura Campbell KEA Technologies Inc, United States George Bahouth, Rebecca Spicer Impact Research, United States Scott Lukas McClean Hospital/Harvard Medical School, United States Robert Strassburger Automotive Coalition for Traffic Safety, Inc., United
States Susan Ferguson Susan Ferguson, United States
Abstract A
large number of fatal crashes every year in the United States is caused by
alcohol-impaired drivers The Automotive Coalition for Traffic Safety and the
National Highway Traffic Safety Administration entered into a research
agreement to explore the feasibility of developing a passive in-vehicle alcohol
detection system, known as the Driver Alcohol Detection System for Safety, with
the goal of significantly reducing the incidence of drunk driving. This paper
presents an analysis of the net benefit that could be achieved by installing
such technology in the passenger vehicle fleet, using a risk-based approach to
model potential outcomes. This outcomes model will calculate the net benefit
of, and the public policy challenges associated with, more widespread use of
non-invasive technology. Such an approach can be beneficial in determining the
merits of the new technology and could be used to help guide public policy with
respect to implementation. Furthermore, the technical data can be used to
further refine the Driver Alcohol Detection System for Safety performance
specifications.
Paper No.23-0316-W
Characterisation of
drowsy driver behaviour and drowsiness baseline data set in a dynamic driving
simulator
Cristina Periago,James Jackson, Clara Cabutí, Fiona Azcarate, Elena Castro, Francesco
Deiana, Adria Roig Applus+ IDIADA, Spain
Abstract Drowsiness
is one of the mean causes of road accidents, accounting for 1,200 fatalities
and 76,000 injuries per year, according to several authors [1]. This
transitional state between awake state and the sleep state behaves
physiological symptoms such as yawning, loss of neck muscle tone, pupillary
constriction, ptosis, decreased attention, psychomotor and cognitive
performance [2]. The purpose of the present study is to observe the effects of
monotonous driving on long journeys on driver behaviour in order to develop
driver monitoring systems capable of detecting symptoms of drowsiness and thus
be able to reduce its negative impact on the road. The experiment is conducted
on a dynamic driving simulator, where conditions were configurated according to
the aim of having a monotonous environment free from any distraction.
Participants drive for 90 minutes and every 5 minutes the experimenter ask
about their level of KSS, using the Karolinska Sleepiness Scale, a standardized
instrument that measures the participant's subjective level of drowsiness.
Moreover, participants are instrumented to collect physiological data (ECG,
EEG, EDA, and respiratory rate) and an eye-tracking system monitors other
drowsiness behaviours such as blinking or yawning. The test finish when 90
minutes passed, or participants reached an advanced level of drowsiness on the
Karolinska Sleepiness Scale (KSS). The study consists of two phases of testing.
The first phase, with 10 participants, aims to validate the test method for
both sleep induction and the integrated data collection setup. The second loop
of testing, planned in January 2023, will involve 20 participants with
different age and gender representation and aim to try to define the sleep
behaviour patterns in relation to the different levels defined by KSS. In this
paper we present the preliminary results of first phase of testing.
Paper No.23-0318-W
Exploring driver
distraction in adaptation to lower levels of automation: Older adult driver
comparisons
Jon Antin,
Charlie Klauer, Shu Han Virginia Tech Transportation Institute, United States Thomas Fincannon
USDOT NHTSA, United States
Abstract This
project examined how middle-aged and older drivers adapt to the use of Level 2
(L2) advanced driver assistance system (ADAS) features (i.e., the system
controls lateral and longitudinal motion). Data were drawn from two
naturalistic driving studies (NDS). In the L2 NDS study, 82 participants were
recruited from the Washington, DC metro area and drove L2 vehicles for four
weeks. A second NDS was conducted with 14 older adults (Older Driver NDS). In
the Older Driver NDS, participants aged 70-79 drove L2 vehicles for six weeks.
Speed setting above the speed limit was significantly more common when L2 was
active than when it was available-but-inactive in the Older Driver NDS dataset.
Older adults had shorter off-road glances than middle-aged drivers in the L2 NDS
when L2 was available, regardless of L2 engagement status. Older drivers showed
shorter glance durations overall. Older adult drivers had fewer glances away
from the forward roadway and were significantly less likely to engage in
secondary tasks when L2 was active. Evidence of older adult driver adaptation
to L2 systems is seen most predominantly in the speed selection.
Paper No.23-0322-W
Exploring driver adaptation
to Lower Levels of Automation (L2) using existing naturalistic driving data
Charlie
Klauer, Marissa Turturici, Shu Han, Gabrial Anderson Virginia Tech Transportation Institute, United States Thomas Fincannon National Highway Traffic Safety
Administration (NHTSA), United States
Abstract This
project evaluated driver adaptation in the hours, days, and months after the
introduction of level 2 (L2) advanced driver assistance system features (i.e.,
the system controls lateral and longitudinal motion) into the driving task. Two
existing naturalistic driving study databases were analyzed: the L2
Naturalistic Driving Study and the Virginia Connected Corridor Elite
Naturalistic Driving Study. To best assess driver adaptation, the analysis
identified three phases of exposure time to L2 features: Phase 1 (immediate,
under 3 hours), Phase 2 (short term, 3 to 8 hours), and Phase 3 (long term,
over 8 hours). The results suggested that driver adaptation was present for
high-risk secondary tasks, as significant increases in engagement were observed
over the three phases, but only when L2 features were active. Additionally,
drivers set their vehicle speed above the speed limit more frequently between
Phases 1 and 2, with higher speeds set when L2 features were active as opposed
to when they were inactive. While these results may be concerning, research
efforts at a larger scale are needed to determine if there is increased crash
risk associated with speeding and high-risk secondary task engagement with L2
features active. We also need to better understand the impact of
traffic/roadway conditions on speed selection with L2 systems.
Paper No.23-0342-W
Role of system status
information in the development of trust and mental models in automated driving
systems
Michael Manser,Lingtao Wu Texas A&M Transportation Institute,
United States Thomas Fincannon USDOT NHTSA, United States John Campbell, Audra Krake, Liberty
Hoekstra-Atwood, Caroline Crump Exponent, United States Abstract Research
Question/Objective: In transportation, mental models are essential to mobility
and safety because drivers rely on them to understand how to interact properly
with their vehicles, the transportation infrastructure, and the environment.
Poor performance and errors can occur when a driver acts in accordance with
inaccurate mental models. Mismatches between mental models and actual
experiences can also lead to reduced trust when, for example, the system with
which they interact fails to perform to their expectations. The current study
examined differing information types regarding Automated Driving System (ADS)
capabilities and limitations on development of mental models and trust while
using simulated Level 3 (L3) systems and a “dual model" use case of Level 4
(L4) systems (i.e., the vehicle can be both manually operated and can be
controlled by ADS in certain ODDs). Method and Data Sources: 48 females and
males between the ages of 25 and 65 had four exposures to L3 and L4 systems in
a driving simulator. Participants used either a basic human machine interface
(HMI) that indicated the ADS was active, or they used an enhanced HMI that
provided additional information indicating when the system was experiencing
limitations (e.g., regarding detection of degraded lane lines). Participants
used a simulated Level 3 system for two exposures and a simulated Level 4
system for two exposures. The acquisition and development of mental models and
trust were assessed with standardized questionnaires. Results: Regardless of
exposure to each system over time, participants' mental models were more
accurate for the simulated Level 4 system compared to the simulated Level 3
system and trust was greater for the simulated Level 4 system during the second
exposure. Discussion and Limitations: This paper summarizes research an ongoing
project, and a final report will be published at a later date. Results of the
current work suggests that the acquisition and development of mental models and
trust can be differentially impacted by how well the ADS performs and the level
of automation. However, because the study relied on simulated Level 3 and Level
4 systems, the results may not represent real world implementations of the
technology.
Chair: Andre Seeck, Germany |
Co-chair: Michiel van Ratingen, Belgium
Paper No.23-0258-W
Euro NCAP Rescue –
Tertiary safety assessment
Simon
Edmonds, Michiel van Ratingen The European New Car Assessment Programme (Euro NCAP),
Belgium Pierre Castaing UTAC, France Claire Petit-Boulanger Renault, France Lt Colonel Michel Gentilleau CTIF, France
Abstract
The European New Car Assessment
Programme (Euro NCAP) has until recently concentrated on passive and active
safety assessments. The organisation realised the need to address post-crash
(tertiary) safety to improve the outcomes for those involved in vehicle
crashes. In 2018 the Rescue working group was created and is supported by Euro
NCAP's members, affiliated members and CTIF (International Association of Fire
& Rescue Services). Industry also contributes with representatives from
both the European Automobile Manufacturers Association (ACEA) and the European
Association of Automotive Suppliers (CLEPA). The first Rescue test and
assessment protocol was published in early 2019 and from the start of 2020 the
topic of Rescue was included in the overall star rating as part of the adult
scoring area. The assessment for Rescue is divided into 3 areas: Rescue –
Rescue Sheets for the vehicle. Extrication - Unlocking of automatic door
locking, door opening forces & seat belt unbuckling forces. Safety -
Advanced eCall and Multi Collision Brake technology. In June 2020 Euro NCAP
launched the “Rescue App" available for Android and iOS users with support from
CTIF and the car manufacturers. This free app gives access to ISO 17840
compliant rescue sheets for hundreds of vehicle models and is constantly
updated. Rescue services re