Browse Topic: Safety testing and procedures

Items (5,359)
Head injuries are a common cause of fatality and long-term impairment in child occupants in motor vehicle crashes. The National Highway Traffic Safety Administration (NHTSA) has developed the Large Omnidirectional Child (LODC) Anthropomorphic Test Device (ATD) where the head was designed to match pediatric biomechanical impact response targets from previous literature. The purpose of this study was to compare experimental and computational results for eight impact directions at 45-degree increments around the LODC head under two levels of impact severity: low and high, corresponding to nominal velocities of 3.08 mm/ms and 5.42 mm/ms, respectively. The experimental setup consists of the LODC head and neck assembly rigidly attached to a circular fixture plate and a hemispherical-shaped impactor 76.2 mm in diameter. The acceleration and angular velocity responses were measured and computed from the LODC finite element (FE) head CG and compared against the experimental data. Experimental
Challa, AbhishiktNoll, Scott
In automotive engineering, seam welds are frequently used to join or connect various parts of structures, frames, cradles, chassis, suspension components, and body. These welds usually form the weaker material link for durability and impact loads, which are measured by lab-controlled durability and crash tests, as well as real-world vehicle longevity. Consequently, designing robust welded components while optimizing for material performance is often prioritized as engineering challenge. The position, dimensions, material, manufacturing variation, and defects all affect the weld quality, stiffness, durability, impact, and crash performance. In this paper, the authors present best practices based on studies over many years, a rapid approach for optimizing welds, especially seam welds, by adopting Design For Six Sigma (DFSS) IDDOV (Identify, Define, Develop, Optimization, and Verification) discrete optimization approach. We will present the case testimony to show the approach throughout
Qin, Wenxin (Daniel)
Pelvic pusher energy absorption pad in a vehicle saves the occupant from pelvic injuries in the event of a crash, especially side or pole crash. This pelvic pusher pad plays a crucial role in absorbing the impact energy from the body side and minimizing the impact to the occupant. Positioning of pelvic pusher pad with respect to occupant manikin position and torso angle, stiffening criteria for the energy absorption pad, maximum force and energy absorption target setting methodology and evaluation methods through CAE and part level physical validations are all discussed in detail. Pelvic pusher pad are of various types such as EPP moulded, blow moulded or injection moulded and the criteria differ for each type. For EPP moulded type, based on the EPP grade, S-S Graph gets converted to F-S Graph and validated accordingly. F-S Graph for a test vehicle is generated through sled test where the sled is made to impact the pelvis of ES2 Dummy at a constant velocity and the F-S Graph is
S M, Rahuld, AnanthaKakani, Phani KumarMalliboina, Mahendra
Sled crash tests are an important tool to develop automotive restraint systems. Compared with full-scale crash tests, the sled test has a shorter development cycle of the restraint system and lower cost. The objective of the present study is to create a cost-effective sled test methodology, calculate the optimal static yaw angle and loading curves, and analyze the motion response and injuries of the dummy in the small overlap crash test. The effectiveness of the proposed methodology was verified under two typical small overlap frontal crash modes: “energy-absorption” and “sideswipe”. The results show that with the calculated yaw angle α, the HIC was different from the small overlap crash model, but all remaining indices were within 5% of the injury criteria. All International Organization for Standardization (ISO) values between the combined accelerations of all parts of the dummy and those of the basic model exceeded 0.75, and some values were above 0.8. Therefore, the proposed sled
Yu, LiuChen, JianzhuoWan, Ming XinFan, TiqiangYang, PeilongNie, ZhenlongRen, LihaiCheng, James Chih
Utilization of fiber-reinforced composite laminates to their full potential requires consideration of angle-ply laminates in structural design. This category of laminates, in comparison with orthotropic laminates, imposes an additional degree of challenge, due to a lack of material principal axes, in determination of elastic laminate effective properties if the same has to be done experimentally. Consequentially, there is a strong inclination to resort to the usage of “CLPT” (Classical Laminated Plate Theory) for theoretically estimating the linear elastic mechanical properties including the cross-correlation coefficients coupling normal and shear effects. As an angle-ply laminate is architecturally comprised of layers of biased orthotropic laminas (based on unidirectional or woven bidirectional fibers), an essential prerequisite for the application of CLPT is an a-priori knowledge of elastic mechanical properties of a constituent lamina. It is natural to expect that the properties of
Tanaya, SushreeDeb, Anindya
Theory and principles of occupant protection for automobiles in rear-end collisions have experienced significant evolution over the decades. Performance of the seatback, specifically the stiffness of the structure, during such a collision has been a subject of particular interest and debate among design engineers, accident reconstruction experts, critics, etc. The majority of current seat designs rely on plastic deformation of the seatback structure to protect the occupant from the dynamics of the crash. In attempt to highlight and provide background information for understanding this subject, this work highlights significant events, research, and publications over the past five decades to illustrate how this subject, automobile design, government regulation and public opinion has evolved. It is observed that technology and design for improving rear-impact protection has received less attention than collisions of other principal directions of force. The different types of
Warner, Wyatt
Reproducing driving scenarios involving near-collisions and collisions in a simulator can be useful in the development and testing of autonomous vehicles, as it provides a safe environment to explore detailed vehicular behavior during these critical events. CARLA, an open-source driving simulator, has been widely used for reproducing driving scenarios. CARLA allows for both manual control and traffic manager control (the module that controls vehicles in autopilot manner in the simulation). However, current versions of CARLA are limited to setting the start and destination points for vehicles that are controlled by traffic manager, and are unable to replay precise waypoint paths that are collected from real-world collision and near-collision scenarios, due to the fact that the collision-free pathfinding modules are built into the system. This paper presents an extension to CARLA’s source code, enabling the replay of exact vehicle trajectories, irrespective of safety implications
Ai, YanAdhikari, BikramPark, Chung-KyuKan, Cing-DaoWijesekera, Duminda
Real-world data show that abdominal loading due to a poor pelvis-belt restraint interaction is one of the primary causes of injury in belted rear-seat occupants, highlighting the importance of being able to assess it in crash tests. This study analyzes the phenomenon of submarining using video, time histories, and statistical analysis of data from a Hybrid III 5th female dummy seated in the rear seat of passenger vehicles in moderate overlap frontal crash tests. This study also proposes different metrics that can be used for detecting submarining in full-scale crash tests. The results show that apart from the high-speed videos, when comparing time-series graphs of various metrics, using a combination of iliac and lap belt loads was the most reliable method for detecting submarining. Five metrics from the dynamic sensors (the maximum iliac moment, maximum iliac force drop in 1 ms, time for 80% drop from peak iliac force, maximum pelvis rotation, and lumbar shear force) were all
Jagtap, Sushant RJermakian, Jessica SEdwards, Marcy A
With the increasing adoption of Zero-Gravity Seats in intelligent cockpits, there is a growing concern over the safety of occupants in reclined postures during collisions. The newly released anthropomorphic test device (ATD), THOR-AV, has modified the neck, spine, and pelvis structures to better match reclined postures. This study aims to investigate the changes in kinematic response and injury metrics for occupants in reclined postures, through high-speed frontal sled tests utilizing the THOR-AV. The tests were conducted using an adjustable rigid seat with a zero-gravity characteristic and an integrated three-point seat belt. Six tests were performed across four seat configurations: Standard, Semi-Reclined, Reclined, and Zero-gravity postures. The input acceleration pulse for these tests was derived from the equivalent double trapezoidal waveform of the Mobile Progressive Deformable Barrier (MPDB) test. Data from sensors and high-speed video were collected for analysis. The results
Wang, QiangLiu, YuFei, JingYang, XiaotingWang, PeifengBai, Zhonghao
Over the last two decades many improvements have been made in stock car racing driver safety. One of these is the head surround, which is rigidly secured to and an integral part of the NASCAR (National Association for Stock Car Auto Racing, LLC) seating environment and serves as an effective restraint for head protection during lateral and rear impacts. However, previous head impact material specifications were optimized for moderate to severe impacts and did not address low severity impacts that occur frequently during typical driving, such as race restart vehicle nose-to-tail contact. This study focused on developing a test methodology for comprehensive evaluation of rear head surround materials for low, moderate and severe impacts. Specifically, this study aimed to formulate a specification that maintains previous material performance during high speed impacts, while decreasing head accelerations at low speed impacts. Quasi-static and dynamic drop tower testing of sample materials
Gray, Alexandra N.Harper, Matthew G.Mukherjee, SayakPatalak, John P.Gaewsky, James
The advancement of high-performance electrification for electric vehicle (EV) development is continuously pushing the boundaries of electric motor technology. The axial flux motor (AFM) represents a promising application for high-performance EVs, offering potential advantages including up to twice the torque density and a 50% reduction in weight compared to regular IPM radial flux motors. The distinctive "pancake" configuration and high axial forces inherent to AFMs present notable NVH challenges, yet there is a lack of research exploring NVH analysis and risk assessment. In this paper, a 10-pole and 12-slot AFM motor is designed, prototyped, and tested, demonstrating the capability to deliver 320 Nm of peak torque and 140 kW of peak power. A comprehensive finite-element model is constructed, and the orthotropic stator material properties are evaluated using modal test data. The dominant axial stator modes are identified as the source of resonances in the system responses. A three
He, SongJensen, WilliamForsyth, AlexanderChang, LeZhang, PengGong, ChengYao, JianZou, YushengFedida, VincentDuan, ChengwuGSJ, Gautam
There are numerous commercially available neck and back support/cushion/pillow devices which are commonly attached to seats by vehicle owners. To our knowledge, there has been no published research on the biomechanical effects of these devices in low-speed rear impacts. To address this, a series of 54 simulated low-speed rear impact tests were conducted using a validated remote-controlled crash sled system. All tests utilized an instrumented BioRID II rear impact anthropomorphic test device (ATD) restrained using a 3-point seatbelt system in a 2018 Toyota Camry LE driver’s seat. Two delta-V ranges were used: a lower range from 7.2 to 8.0 kph (4.5 to 5.0 mph) and a higher range from 10.5 to 11.3 kph (6.5 to 7.0 mph). Six neck only devices, one combination neck and back device, and three back only devices were assessed. Two tests per delta-V range for each device and each device adjustment position were conducted and compared against five reference tests without any devices at each delta
Phan, AndrewGross, JamieUmale, SagarCrowley, ShannonGlasser, GabrielFurbish, Christopher
Off-road vehicles are required to traverse a variety of pavement environments, including asphalt roads, dirt roads, sandy terrains, snowy landscapes, rocky paths, brick roads, and gravel roads, over extended periods while maintaining stable motion. Consequently, the precise identification of pavement types, road unevenness, and other environmental information is crucial for intelligent decision-making and planning, as well as for assessing traversability risks in the autonomous driving functions of off-road vehicles. Compared to traditional perception solutions such as LiDAR and monocular cameras, stereo vision offers advantages like a simple structure, wide field of view, and robust spatial perception. However, its accuracy and computational cost in estimating complex off-road terrain environments still require further optimization. To address this challenge, this paper proposes a terrain environment estimating method for off-road vehicle anticipated driving area based on stereo
Zhao, JianZhang, XutongHou, JieChen, ZhigangZheng, WenboGao, ShangZhu, BingChen, Zhicheng
With the widespread application of the Automatic Emergency Braking System (AEB) in vehicles, its impact on pedestrian safety has received increasing attention. However, after the intervention of AEB, the kinematic characteristics of pedestrian leg collisions and their corresponding biological injury responses also change. At the same time, in order to accurately evaluate the pedestrian protection performance of vehicles, the current assessment regulations generally use advanced pedestrian protection leg impactors (aPLI) and rigid leg impactors (TRL) to simulate the movement and injury conditions of pedestrian legs. Based on this, in order to explore the collision boundary conditions and changes in injury between vehicles and APLI and TRL leg impactors under the action of AEB, this paper first analyzes the current passive and active assessment conditions. Secondly, the simulation software LS-DYNA is used to build a finite element model of APLI and TRL impactor-vehicle collisions to
Ye, BinHong, ChengWan, XinmingLiu, YuCheng, JamesLong, YongchenHao, Haizhou
In the Baja race, off-road vehicles need to run under a variety of real and complex off-road conditions such as pebble road, shell pit, stone bad road, hump, water puddle, etc. In the process of this high-intensity and high-concentration race, the unoptimized design of the cab in ergonomics will easily cause the driver's visual and handling fatigue, so that the driver's attention is not concentrated. Cause the occurrence of security accidents. Moreover, lower back pain, sciatic nerve discomfort, lumbar spine diseases and other occupational diseases are basically caused by uncomfortable driving posture and unreasonable control matching, and these have a lot to do with unreasonable ergonomic design. In order to solve these problems, firstly establish the human body model of the driver, and then build the BSC racing car model by using 3D modeling software Catia. Then use the ergonomics simulation software Jack to analyze the visibility, accessibility and comfort. Based on the simulation
Liu, YuzhouLiu, Silang
With the advancement of intelligent transportation and smart logistics systems, tractor semi-trailers have gradually become one of the primary modes of transport due to their substantial cargo capacity. However, the growing number of tractor semi-trailers has raised significant traffic safety concerns. Due to their significant spring mass and strong body strength, accidents involving tractor semitrailers often result in severe consequences. Active collision avoidance control strategies provide assurance for vehicle safety. However, existing research predominantly focuses on passenger cars and small commercial vehicles. Research specifically addressing tractor semi-trailers, which have longer bodies and more complex dynamic characteristics, is relatively sparse. Therefore, this paper proposes a collision risk assessment-based longitudinal collision avoidance control strategy for tractor semi-trailers with slip ratio control. Firstly, the paper introduces the braking characteristics and
Yan, YangZheng, HongyuZhang, Yuzhou
Emerging automotive technologies like advanced driver assistance systems (ADAS) and automated driving systems (ADS) hold promise for improving safety for the traveling public; however, effective verification and validation (V&V) of these systems has proven to be challenging. Traditional testing methodologies may serve in limited cases for systems exhibiting low levels of automation, but recent studies show that these systems that have been brought to market perform poorly in practice. Further, these traditional methods do not serve for testing systems with high levels of automation where a human driver simply serves as a fallback ready user or is out of the loop altogether. New V&V methods are required to assess whether these systems can perform their intended functions in their intended operating environments, and to assess whether they can do so safely across the expansive and variable operating space. This paper presents an overview of ADAS and ADS challenges and novel approaches to
Thorn, EricKnisley, VeronicaAuchter, Joseph
As the high-quality development of the new energy vehicle (NEV) and traction battery industries, the safety of traction batteries has become a global focus. Typically mounted at the bottom of NEVs, traction battery systems are particularly vulnerable to mechanical damage caused by bottom impacts, posing serious safety risks. This study investigates the damage sustained by NEV traction battery systems during bottom impact collisions, using computer tomography analysis to detail the damage mechanisms. The findings provide valuable data to enhance the safety and protective performance of traction batteries under such scenarios.
Yan, PengfeiWang, FangMa, TianyiHan, CeHe, Gaiyun
In recent years, energy scarcity and environmental pollution have intensified globally, prompting increased research and development in new energy vehicles as countries prioritize environmental protection and energy conservation. Compared to fuel-powered vehicles, new energy vehicles have relatively larger battery volumes and weights, which can increase damage and the risk of fires and explosions in collisions. To analyze and optimize the safety performance of a specific vehicle model's battery pack, we constructed a finite element model using existing software and performed pre-processing, simulation, and analysis of modal, random vibration, and extrusion characteristics. This revealed specific damage scenarios and enabled reliability analysis under working conditions. To enhance safety and reduce mass, we parametrically modeled power pack components and optimized parameters via multi-objective genetic algorithms under three road conditions. Results indicate reduced mass and improved
Wang, Zhi
The National Highway Traffic Safety Administration (NHTSA) published an Advance Notice of Proposed Rulemaking (ANPRM) to update the Federal Motor Vehicle Safety Standard (FMVSS) 207. Part of the ANPRM is to assess the merit of conducting quasi static body block seat pull tests and conducting FMVSS 301 rear crash tests at 80 km/h or higher with a 95th percentile ATD lap-shoulder belted in the front seats and limiting seatback deflection to 15 to 25 degrees. Prior to updating regulations, it is important to understand the seating design history and implications. This study was conducted to provide a historical background on seat design and performance using literature and test data. One objective was to first define the terminology used to describe occupant kinematics in rear crashes. Secondly, seat design evolution is then discussed. Third, test methods and test results were summarized, and fourth, the field performance are synopsized and discussed with respect to 2nd row occupant
Parenteau, ChantalBurnett, RogerDavidson, Russell
The rapid development of intelligent and connected vehicles is transforming them into data-rich information carriers, which generate and store vast amounts of sensitive information. However, the frequent sharing of resources within these vehicles poses substantial risks to user privacy and data security. Should sensitive resources be accessed maliciously, the consequences could be severe, leading to significant threats to the safety, property, and reputation of both drivers and passengers. To address these risks, this paper proposes an adaptive risk-based access control with Trusted Execution Environment (TEE) specifically designed for vehicles, aimed at managing and restricting access permissions based on risk assessments. Firstly, this paper designs an adaptive risk model in accordance with ISO/SAE 21434, taking into account factors such as the security levels of subjects and objects, context, and the risk history of subjects to separately quantify threats and impacts. By adjusting
Luo, FengLi, ZhihaoWang, JiajiaLuo, Cheng
In the pre-crash emergency braking scenario, the occupant inside the vehicle will move forward due to inertia, deviating from the standard upright seating position for which conventional restraint systems are designed. Previous studies have mainly focused on the influence of out-of-position (OOP) displacement on occupant injuries in frontal collisions, and provided solutions such as active pretensioning seatbelts (APS). But little attention has been paid to the influence of OOP on whiplash injury during a subsequent rear-end collision. To investigate the forward OOP impact on whiplash injuries and the effectiveness of APS in this accident scenario, a vehicle interior model with an active human body model (AHBM) was setup in the MADYMO simulation platform. Different braking strengths (0.8g and 1.1g), APS triggering times (from 0.2s before to 0.2s after the braking initiation) and pretensioning forces (from 100N to 600N) were input to the simulation matrix. The occupant’s forward OOP
Fei, JingQiu, HangWang, PeifengLiu, YuCheng, James ChihZhou, QingTan, Puyuan
A total of 148 tests were conducted to evaluate the Forward Collision Warning (FCW) and Automatic Emergency Braking (AEB) systems in five different Tesla Model 3 vehicles between model years 2018 and 2020 across four calendar years. These tests involved stationary vehicle targets, including a foam Stationary Vehicle Target (SVT), a Deformable Stationary Vehicle Target (DSVT), a live vehicle with brake lights, and a SoftCar360 designed for high-speed impact tests. The evaluations were conducted at speeds of 35, 50, 60, 65, 70, 75, and 80 miles per hour (mph) during both daytime and nighttime conditions and utilized early and medium FCW settings. These settings, part of Tesla's Collision Avoidance AssistTM, modify object detection alerts and the timing of visual and auditory warnings issued to drivers. The 2018 to 2020 vehicles initially utilized cameras, radar and ultrasonic sensors (USS) for object detection. Tesla updated their Autoilot software and detection algorithms to a vision
Harrington, ShawnNagarajan, Sundar Raman
Peak upper and lower neck load data from rear impact crash testing were reviewed, aggregated, and analyzed from over 1,800 tests of existing peer-reviewed literature and research as well as available testing conducted by the Insurance Institute for Highway Safety (IIHS) and the National Highway Traffic Safety Administration (NHTSA). Both human volunteers and anthropomorphic test devices (ATDs) were subjects of the reviewed studies and testing. Peak upper and lower neck axial forces (compression and tension), sagittal shear forces, and sagittal moments (flexion and extension) from available crash testing were reported and analyzed as functions of measured change in velocity (delta-V) ranging from approximately 3 to 60 km/h (1.9 to 37 mph). This load data was then further analyzed for possible trends amongst various testing conditions, such as seat type, ATD used, and subject seating position within the vehicle chassis and seat to develop a simple linear model. The linear regressions
Kazmierczak, AlexUmale, SagarVisalli, AlyssaWebb, EllaKashdan, AryehRandles, BryanWelcher, Judson
The integrated vehicle crash safety design provides longer pre-crash preparation time and design space for the in-crash occupant protection. However, the occupant’s out-of-position displacement caused by vehicle’s pre-crash emergency braking also poses challenges to the conventional restraint system. Despite the long-term promotion of integrated restraint patterns by the vehicle manufacturers, safety regulations and assessment protocols still basically focus on traditional standard crash scenarios. More integrated crash safety test scenarios and testing methods need to be developed. In this study, a sled test scenario representing a moderate rear-end collision in subsequence of emergency braking was designed and conducted. The bio-fidelity of the BioRID II ATD during the emergency braking phase is preliminarily discussed and validated through comparison with a volunteer test. The final forward out-of-position displacement of the BioRID II ATD falls within the range of volunteer
Fei, JingWang, PeifengQiu, HangLiu, YuShen, JiajieCheng, James ChihZhou, QingTan, Puyuan
Camera matching photogrammetry is widely used in the field of accident reconstruction for mapping accident scenes, modeling vehicle damage from post collision photographs, analyzing sight lines, and video tracking. A critical aspect of camera matching photogrammetry is determining the focal length and Field of View (FOV) of the photograph being analyzed. The intent of this research is to analyze the accuracy of the metadata reported focal length and FOV. The FOV from photographs captured by over 20 different cameras of various makes, models, sensor sizes, and focal lengths will be measured using a controlled and repeatable testing methodology. The difference in measured FOV versus reported FOV will be presented and analyzed. This research will provide analysts with a dataset showing the possible error in metadata reported FOV. Analysts should consider the metadata reported FOV as a starting point for photogrammetric analysis and understand that the FOV calculated from the image
Smith, Connor A.Erickson, MichaelHashemian, Alireza
Research on modeling head injury metrics and head acceleration waveforms from real-world collisions has been limited compared to vehicle crash pulses. Prior studies have used rectangular, triangular, polynomial, half-sine, and haversine pulse functions to model vehicle crash pulses and have employed more complex approximations for head injury metrics. This study aimed to develop a method to predict 15 ms Head Injury Criterion (HIC15) in frontal passenger vehicle impacts using these simple pulse functions, where only occupant peak head acceleration and head impact duration are known. Vehicle crash tests from the New Car Assessment Program (NCAP) were selected for frontal impacts that included driver occupants. Head acceleration and shoulder belt load channels of Hybrid III 50th percentile male anthropomorphic test devices were collected and separated for training a set of ratios and testing their performance. Rectangular, triangular, quadratic, half-sine, and haversine pulse functions
Westrom, ClydeTanczos, RachelAdanty, KevinShimada, Sean
The rapid growth of electric vehicles (EVs) has led to a significant increase in vehicle mass due to the integration of large and heavy battery systems. This increase in mass has raised concerns about collision energy and the associated risks, particularly in high-speed impacts. As a consequence, crashworthiness evaluations, especially front-impact regulations, have become increasingly stringent. Crash speed between the vehicle and the Mobile Progressive Deformable Barrier (MPDB) is increasing, reflecting the growing emphasis on safety in the automotive industry. Moreover, a new frontal pole crash scenario is under consideration for future regulatory standards, highlighting the continuous evolution of crash testing protocols. To ensure occupant protection and battery safety, manufacturers have traditionally used Hot Blow Forming technology for producing closed-loop dash lower cross member components. However, this process is both costly and energy-intensive, necessitating more
Lee, JongminKim, DonghyunJang, MinhoKim, GeunhoSeongho, YooKim, Kyu-Rae
The development of autonomous driving technology will liberate the space in the car and bring more possibilities of comfortable and diverse sitting postures to passengers, but the collision safety problem cannot be ignored. The aim of this study is to investigate the changes of injury pattern and loading mechanism of occupants under various reclined postures. A highly rotatable rigid seat and an integrated three-point seat belt were used, with a 23g, 50kph input pulse. Firstly, the sled test and simulation using THOR-AV in a reclined posture were conducted, and the sled model was verified effective. Based on the sled model, the latest human body model, THUMS v7, was used for collision simulation. By changing the angle of seatback and seat pan, 5 seat configurations were designed. Through the calculation of the volunteers' pose regression function, the initial position of THUMS body parts in different seat configurations was determined. The responses of human body parts were output
Yang, XiaotingWang, QiangLiu, YuFei, JingWang, PeifengLi, ZhenBai, Zhonghao
India has one of the highest accident rates in the world. Quite a few accidents have been attributed to poor driver visibility. Driver visibility is an important factor that can help mitigate the risk of accidents. The optimal visibility of in-vehicle controls is also essential for improving driver experience. Optimized driver visibility improves driving comfort and gives confidence to the driver, ensuring the safety of drivers and subsequently that of pedestrians. Driver visibility is an important consideration for vehicle occupant packaging and SAE has defined various standards and regulations for the same. These guidelines are defined considering American anthropometry, helping OEMs create global vehicles with uniform checkpoints. However, due to anthropometric differences, a need was felt to capture and analyze Indian-specific eyellipse and eye points. To measure the eye point of the user in a controlled environment, the interiors of a passenger vehicle were simulated using a
P H, SalmanKalra, PreritaRawat, AshishSharma, DeepakSingh, Ashwinder
Two wheelers motorcycles are used for many purposes e.g. commuting from one place to another, long highway rides, racing and off-roading. Motorcycles which are used in off-road conditions require higher suspension strokes to absorb large oscillations due to terrain conditions. These motorcycles undergo jumps of varying heights and different vehicle orientations. In some of the dynamic situations front wheel may land on the ground before the rear and in other cases it may be vice versa. To make sure that the vehicle is durable enough to withstand loads in such operating conditions, vehicle drop test was developed in test lab where vehicle is dropped from predefined heights in both front & rear wheel landing conditions. Same test case is simulated in multibody dynamics to capture loads at important connections of the frame. This paper presents the correlation exercise carried out to validate MBD model and simulation process with test data captured during lab test. Accelerations at
Jain, Arvind KumarNirala, Deepak
This study outlines a camera-based perspective transformation method for measuring driver direct visibility, which produces 360-degree view maps of the nearest visible ground points. This method is ideal for field data collection due to its portability and minimal space requirements. Compared with ground truth assessments using a physical grid, this method was found to have a high level of accuracy, with all points in the vehicle front varying less than 0.30 m and varying less than 0.6 m for the A- and B-pillars. Points out of the rear window varied up to 2.4 m and were highly sensitive to differences in the chosen pixel due to their greater distance from the camera. Repeatability through trials of multiple measurements per vehicle and reproducibility through measures from multiple data collectors produced highly similar results, with the greatest variations ranging from 0.19 to 1.38 m. Additionally, three different camera lenses were evaluated, resulting in comparable results within
Mueller, BeckyBragg, HadenBird, Teddy
Abstract This paper introduces a method to solve the instantaneous speed and acceleration of a vehicle from one or more sources of video evidence by using optimization to determine the best fit speed profile that tracks the measured path of a vehicle through a scene. Mathematical optimization is the process of seeking the variables that drive an objective function to some optimal value, usually a minimum, subject to constraints on the variables. In the video analysis problem, the analyst is seeking a speed profile that tracks measured vehicle positions over time. Measured positions and observations in the video constrain the vehicle’s motion and can be used to determine the vehicle’s instantaneous speed and acceleration. The variables are the vehicle’s initial speed and an unknown number of periods of approximately constant acceleration. Optimization can be used to determine the speed profile that minimizes the total error between the vehicle’s calculated distance traveled at each
Snyder, SeanCallahan, MichaelWilhelm, ChristopherJohnk, ChrisLowi, AlvinBretting, Gerald
The National Highway Safety Administration (NHTSA) recently published an Advanced Notice of Proposed Rulemaking (ANPRM) to evaluate seat performance in rear impacts [1]. The ANPRM was issued partially in response to two petitions requesting an increase in seatback strength requirements and high-speed testing with various size Anthropometric Test Devices (ATDs). To better understand the effect of these requests, this study evaluates ATD responses with two high-speed rear sled conditions, three occupant sizes and various seat designs. Seat designs varied from modern conventional seats with yielding properties to stronger and stiffer seats represented by seat integrated restraint (SIR) designs, and rigidized SIR seats. Twenty-four rear sled tests were analyzed. The tests were matched by crash severity, seat designs (strength), ATD sizes and initial postures (nominal/in-position, leaned forward and leaned outboard). The test data and videos were reviewed to identify time coinciding with
Parenteau, ChantalBurnett, Roger
In new energy vehicles, aluminum alloy has gained prominence for its ability to achieve superior lightweight properties. During the automotive design phase, accurately predicting and simulating structural performance can effectively reduce costs and enhance efficiency. Nevertheless, the acquisition of accurate material parameters for precise predictive simulations presents a substantial challenge. The Johnson-Cook model is widely utilized in the automotive industry for impact and molding applications due to its simplicity and effectiveness. However, variations in material composition, processing techniques, and manufacturing methods of aluminum alloy can lead to differences in material properties. Additionally, components are constantly subjected to complex stress states during actual service. Conventional parameter calibration methods primarily rely on quasi-static and dynamic tensile tests, offering limited scope in addressing compression scenarios. This paper proposes an inversion
Kong, DeyuGao, Yunkai
Videos from cameras onboard a moving vehicle are increasingly available to collision reconstructionists. The goal of this study was to evaluate the accuracy of speeds, decelerations, and brake onset times calculated from onboard dash cameras (“dashcams”) using a match-moving technique. We equipped a single test vehicle with 5 commercially available dashcams, a 5th wheel, and a brake pedal switch to synchronize the cameras and 5th wheel. The 5th wheel data served as the reference for the vehicle kinematics. We conducted 9 tests involving a constant-speed approach (mean ± standard deviation = 57.6 ± 2.0 km/h) followed by hard braking (0.989 g ± 0.021 g). For each camera and brake test, we extracted the video and calculated the camera’s position in each frame using SynthEyes, a 3D motion tracking and video analysis program. Scale and location for the analyses were based on a 3D laser scan of the test site. From each camera’s position data, we calculated its speed before braking and its
Flynn, ThomasAhrens, MatthewYoung, ColeSiegmund, Gunter P.
Impact resistance is crucial for assessing charging pile safety and reliability. This study proposes a prediction model, called GA-BP neural network, which achieved prediction errors below 5% and reduced computation time by over 95% in comparison to finite element analysis (FEA). Initially, the charging pile impact test platform is constructed, and a matching finite element simulation model is developed. The correctness of the simulation model is then verified by integrating the experimental findings. Furthermore, the Latin hypercube approach is used to create 200 sets of simulation schemes, and using the Python programming language, the impact resistance performance indicators of charging piles are automatically collected. Next, a genetic algorithm is used to optimize the initial weight and bias of the BP neural network, lastly, fine-tune the hyperparameters in the neural network to develop a prediction model for the impact resistance performance of the charging pile. The GA-BP model
Jiang, BingyunHu, PengLiu, ZhenyuYuan, PengfeiLiu, Hui
Scenario-based testing has become one of the important elements to evaluate the performance of automated vehicle systems before deploying on actual road. There are several approaches that can be used to conduct scenario-based testing via simulation approach. One of the important aspects in scenario-based safety testing is the driver-in-the-loop (DiL) simulation where it involves integration of hardware and human interaction. Therefore, motion platform-based vehicle driving simulators are commonly used for the DiL simulation for scenario-based testing. Generally, a high degree of freedom driving simulator is used for scenario-based testing such as 6 degrees of freedom (DoF) to achieve high accuracy to represent an actual vehicle response. Moreover, most of the motion platforms are designed using hexapod configuration, which also contributes to 6-DoF. However, this type of design requires large space to conduct the testing because the field of motion (FoM) is high in three axes and high
Kleolee, KahOnnAparow, Vimal RauCheok, Jun Hongde Boer, NielsJamaluddin, Hishamuddin
Background. In 2022, vulnerable road user (VRU) deaths in the United States increased to their highest level in more than 40 years. At the same time, increasing vehicle size and taller front ends may contribute to larger forward blind zones, but little is known about the role that visual occlusion may play in this trend. Goal. Researchers measured the blind zones of six top-selling light-duty vehicle models (one pickup truck, three SUVs, and two passenger cars) across multiple redesign cycles (1997–2023) to determine whether the blind zones were getting larger. Method. To quantify the blind zones, the markerless method developed by the Insurance Institute for Highway Safety was used to calculate the occluded and visible areas at ground level in the forward 180° arc around the driver at ranges of 10 m and 20 m. Results. In the 10-m forward radius nearest the vehicle, outward visibility declined in all six vehicle models measured across time. The SUV models showed up to a 58% reduction
Epstein, Alexander K.Brodeur, AlyssaDrake, JuwonEnglin, EricFisher, Donald L.Zoepf, StephenMueller, Becky C.Bragg, Haden
This standard documents what is required to execute a System Theoretic Process Analysis (STPA) of safety-critical products or systems in all industries. This standard defines the terminology, the steps in using STPA, the activities flow, and the expected deliverables. This standard may be used when addressing compliance with contractual or regulatory requirements regarding risk assessments, safety assessments, development assurance, system security engineering, or other similar requirements as appropriate. In addition, this standard can be used to demonstrate that an effective STPA evaluation has been conducted when compliance is not of paramount concern. This standard is applicable to a broad set of uses including, but not limited to, corporate product development processes, organizational processes, regulatory groups, supplier processes, defense programs (e.g., government awards a contract to a company and the contract mandates STPA), defense program office (e.g., government safety
Functional Safety Committee
The purpose of this study was to investigate the use of quasistatic force deformation (QSFD) data to represent the collision forces in low-speed collinear collisions when there is damage to vehicle body structures as well as the bumpers. In this study five full-scale underride/override crash tests were performed and simulated with QSFD data. In each crash test a bumper or a trailer underride guard on a bullet vehicle overrode the rear or front bumper of a target vehicle and damaged structures above the bumper of the target vehicle. A QSFD measurement was performed substantially similar to the vehicle interactions in the crash using a complete exemplar target vehicle that was rigidly attached to the earth. The output of a QSFD measurement is force deflection data for the vehicle pair. Each crash test was simulated using the QSFD data, the weights of the test vehicles, the closing speed of the test vehicles, and the restitution measured in the crash test. The output of a simulation was
Gall, JessicaScott, William R.Bonugli, EnriqueWatson, Richard A.Fischer, Patrick
To further optimize the automatic emergency braking for pedestrian (AEB-P) control algorithm, this study proposes an AEB-P hierarchical control strategy considering road adhesion coefficient. First, the extended Kalman filter is used to estimate the road adhesion coefficient, and the recursive least square method is used to predict the pedestrian trajectory. Then, a safety distance model considering the influence factor of road adhesion coefficient is proposed to adapt to different road conditions. Finally, the desired deceleration is converted into the desired pressure and desired current to the requirements of the electric power-assisted braking system. The strategy is verified through the hardware-in-the-loop (HIL) platform; the simulation results show that the control algorithm proposed in this article can effectively avoid collision in typical scenarios, the safe distance of parking is between 0.61 m and 2.34 m, and the stop speed is in the range of 1.85 km/h–27.64 km/h.
Wang, ZijunWang, LiangMa, LiangSun, YongLi, ChenghaoYang, Xinglong
Secondary crashes, including struck-by incidents are a leading cause of line-of-duty deaths among emergency responders, such as firefighters, law enforcement officers, and emergency medical service providers. The introduction of light-emitting diode (LED) sources and advanced lighting control systems provides a wide range of options for emergency lighting configurations. This study investigated the impact of lighting color, intensity, modulation, and flash rate on driver behavior while traversing a traffic incident scene at night. The impact of retroreflective chevron markings in combination with lighting configurations, as well as the measurement of “moth-to-flame” effects of emergency lighting on drivers was also investigated. This human factors study recruited volunteers to drive a closed course traffic incident scene, at night under various experimental conditions. The simulated traffic incident was designed to replicate a fire apparatus in the center-block position. The incident
D. Bullough, JohnParr, ScottHiebner, EmilySblendorio, Alec
To improve the accuracy and reliability of short-term prediction of highway visibility level in key scenarios such as short duration and fast changing speed, this paper proposes a short-term prediction method for highway visibility level based on attention mechanism LSTM. Firstly, XGBoost and SHAP methods are used to analyze the factors affecting highway visibility, determine the importance ranking of different influencing factors, and select the factors that have a greater impact on visibility as inputs for the visibility level prediction model. Secondly, based on LSTM as the model foundation network and innovative coupling attention mechanism, a visibility level prediction model based on attention mechanism LSTM is constructed, which can dynamically update the correlation between meteorological feature information at each historical time point and the visibility level at the current prediction time, thereby dividing the importance of information and flexibly capturing important
Ding, ShanshanXiong, ZhuozhiHuang, XuLi, Yurong
The rapid expansion of metro systems in major cities worldwide has resulted in the accumulation of vast amounts of travel data through Automatic Fare Collection (AFC) systems. While this data is crucial for enhancing and optimizing transportation networks, it also raises significant concerns regarding passenger privacy due to the potential exposure of individual travel patterns. In this paper, we propose a novel privacy risk assessment model aimed at quantifying the uniqueness of travel trajectories and evaluating the associated privacy threats. Utilizing AFC data from Chengdu collected in March 2021, we first employ an information entropy approach to assess the uniqueness of travel trajectories across different time granularities. We then apply the K-Means clustering algorithm to classify these trajectories into categories based on their uniqueness levels, enabling us to investigate how factors like travel time and routes influence trajectory uniqueness. To further understand the
Fan, XiaotingQu, XuYang, Hongtai
This paper presents a highway accident risk assessment model based on a Bayesian random-parameters logit model, aiming to evaluate the effects of real-time traffic conditions on crash risks on freeways. By incorporating random parameters to account for variations in the impacts of traffic variables across different freeway segments, the model offers greater flexibility and adaptability compared to traditional fixed-parameters logit models. The study utilizes traffic flow data collected from the Hangzhou-Shanghai-Ningbo expressway over a 14-month period, analyzing factors such as traffic density, average vehicle speed, and lane-changing frequency. The estimation process employs Markov Chain Monte Carlo (MCMC) methods, including Gibbs sampling and Metropolis-Hasting algorithms, to ensure model convergence and stability. Empirical results demonstrate significant impacts of these traffic variables on crash risks and successfully identify key variables with random effects, enhancing the
Feng, ShiWang, ZichenLiu, ShaoweihuaWang, FengZhang, YujieLuo, Xi
Highway construction zones present substantial safety challenges due to their dynamic and unpredictable traffic conditions. With the rising number of highway projects, limited accident data during brief construction phases underscores the need for alternative safety evaluation methods, such as traffic conflict analysis. This study addresses vehicular safety issues within the Kunshan section of the Shanghai-Nanjing Expressway, focusing on conflict risk assessment through a spatio-temporal analysis of a construction zone. Using drone-captured video, vehicle trajectories were extracted to derive key operational indicators, including speed and acceleration, providing a spatio-temporal foundation for analyzing traffic flow and conflict dynamics. A novel **Comprehensive Collision Risk Index (CCRI)** was introduced, integrating Time-to-Distance-to-Collision (TDTC) and Enhanced Time-to-Collision (ETTC) metrics to enable a multidimensional assessment of conflict risk. The CCRI captures both
Zhang, YuwenGuo, XiuchengMa, Yuheng
The transition from manual to autonomous driving introduces new safety challenges, with road obstacles emerging as a prominent threat to driving safety. However, existing research primarily focuses on vehicle-to-vehicle risk assessment, often overlooking the significant risks posed by static or dynamic road obstacles. In this context, developing a system capable of real-time monitoring of road conditions, accurately identifying obstacle positions and characteristics, and assessing their associated risk levels is crucial. To address these gaps, this study proposes a comprehensive process for rapid obstacle identification and risk quantification, composed of three main components: road obstacle event detection and feature extraction, risk quantification and level assessment, and output of warning information and countermeasures. First, a rapid detection method suited for highway scenarios is proposed based on the YOLOv5 model, enabling fast detection and classification of obstacles in
Chen, TingtingChen, LeileiYu, WenluChen, Daoxie
Overloading of trucks will not only damage road infrastructure, lead to exhaust pollution, and even cause serious traffic accidents, resulting in huge losses of life and property. However, most of the methods to evaluate truck overloading are limited by environmental factors, so it is impossible to monitor truck overloading in real time. In order to solve this problem, a truck overload detection method based on real-time vehicle diagnosis big data is proposed in this paper. The method comprehensively considers multiple factors affecting the actual power of trucks through mathematical modeling. It based on the effects of overload on fuel combustion efficiency, harmful gas emission, exhaust temperature, and vehicle power loss, The truck overload evaluation model is constructed to judge whether the truck is overloaded or not in real time. Based on the truck overload assessment and truck accident risk factor extraction , a real-time operation risk assessment model based on fault tree
Chen, YuguangLin, HonghaoWang, Yanan
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