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Viewing 151 to 180 of 16146
2015-04-14
Technical Paper
2015-01-1405
Guanjun Zhang, Feng Yu, Zhigao OuYang, Huiqin Chen, Zhonghao Bai, Libo Cao
Abstract The combination of passive and active vehicle safety technologies can effectively improve vehicle safety. Most of them predict vehicle crashes using radar or video, but they can't be applied extensively currently due to the high cost. Another collision forecasting method is more economic which is based on the driver behavior and vehicle status, such as the acceleration, angular velocity of the brake pedal and so on. However, the acceleration and angular velocity of the brake pedal will change with the driver and the vehicle type. In order to study the effect of different drivers and vehicle types on the braking acceleration and angular velocity of the brake pedal, six volunteers were asked to drive five vehicles for simulating the working conditions of emergency braking, normal braking, inching braking and passing barricades under different velocities. All the tests were conducted on asphalt road, and comprehensive experimental design was used to arrange tests.
2015-04-14
Journal Article
2015-01-1408
Kristofer D. Kusano, Hampton C. Gabler
Abstract Intersection crashes are a frequent and dangerous crash mode in the U.S. Emerging Intersection Advanced Driver Assistance Systems (I-ADAS) aim to assist the driver to mitigate the consequences of vehicle-to-vehicle crashes at intersections. In support of the design and evaluation of such intersection assistance systems, characterization of the road, environment, and drivers associated with intersection crashes is necessary. The objective of this study was to characterize intersection crashes using nationally representative crash databases that contained all severity, serious injury, and fatal crashes. This study utilized four national crash databases: the National Automotive Sampling System, General Estimates System (NASS/GES); the NASS Crashworthiness Data System (CDS); and the Fatality Analysis Reporting System (EARS) and the National Motor Vehicle Crash Causation Survey (NMVCCS).
2015-04-14
Technical Paper
2015-01-1410
Shotaro Odate, Kazuhiro Daido, Yosuke Mizutani
According to the National Automotive Sampling System (NASS) Crashworthiness Data System (CDS), which is a North American automobile accident database, collision events referred to as multiple-collision accidents, in which multiple collisions occur during travel, account for 55% of all accidents. In addition, multiple-collision accidents in which collision events following the first collision event are more severe than the first event account for 20% of all accidents. In a first collision, the system had simultaneously operated to restrain and protect the vehicle occupant. If the multiple-collision accidents occurs, because the system for restraining and protecting vehicle occupants will have already deployed, the performance of the system can be limited from subsequent collisions.
2015-04-14
Technical Paper
2015-01-1406
Mikael Ljung Aust, Lotta Jakobsson, Magdalena Lindman, Erik Coelingh
This paper presents and discusses the continuous evolution of the developments in the area of collision avoidance systems. Collision avoidance systems have been on the market for a decade, and the development has been rapid. Starting with forward collision warning with brake support targeting vehicles moving in the same direction in front of the car, collision avoidance systems now cover pedestrians and cyclists in front of the car as well as vehicles standing still and even some situations of approaching vehicles in crossings. The development up to date, along with future challenges, are described and discussed according to challenge areas; e.g. detection, decision strategy and intervention strategy. Also, ways of assessing system effects are discussed. Numerous studies have been made predicting the effect of different systems, and the real world effects of these systems have been shown to be significant.
2015-04-14
Technical Paper
2015-01-1413
Louis Tijerina, Michael Blommer, Reates Curry, Radhakrishnan Swaminathan, Dev Kochhar, Walter Talamonti
Abstract This paper investigates the effects on response time of a forward collision event in a repeated-measures design. Repeated-measures designs are often used in forward collision warning (FCW) testing despite concerns that the first exposure creates expectancy effects that may dilute or bias future outcomes. For this evaluation, 32 participants were divided into groups of 8 for an AA, BB, AB, BA design (A= No Warning; B=FCW alert). They drove in a high-fidelity simulator with a visual distraction task. After driving 15 min in a nighttime rural highway environment, a forward collision threat arose during the distraction task (Period 1). A second drive was then run and the forward collision threat was repeated again after ∼10 min (Period 2). The response times from these consecutive events were analyzed.
2015-04-14
Technical Paper
2015-01-1414
Jitendra Shah, Mohamed Benmimoun
In the framework of large scale project interactIVe co-funded by the European Commission Ford has developed an active safety system for the supported and autonomous avoidance of rear end collisions by intervention of braking and steering systems. This paper focuses on the assessment of threat perceived by drivers in collision avoidance situation. The decision making related to the initiation of the interventions by driver is crucial to understand how much threat is the driver can hold. The study has helped to understand how driver feels a threat arising from environment. It is a step towards autonomous driving where the system interventions have to be initiated as early as possible in order to avoid the collision and avoid unstable vehicle dynamics situations. In parallel the reaction has to be delayed long enough until it is likely that the driver will no longer intervene or respectively he is no longer able to intervene. For this reason an experiment is conducted with 26 subjects.
2015-04-14
Technical Paper
2015-01-1411
Caroline Crump, David Cades, Robert Rauschenberger, Emily Hildebrand, Jeremy Schwark, Brandon Barakat, Douglas Young
Advanced Driver Assistive System technologies are currently available in many passenger vehicles that provide safety benefits and will ultimately lead to autonomous, “self-driving” vehicles. One technology that has the potential for having substantial safety benefits is the forward collision warning and mitigation (FCWM) system, which is designed to (1) warn drivers of imminent front-end collisions, (2) potentiate driver braking responses, and (3) have the ability to apply the vehicle’s brake autonomously to slow, or, in some cases, stop the vehicle prior to a forward collision. Although the proliferation of such technologies can, in many ways, mitigate the necessity of a timely braking response by a driver in an emergency situation, how this system affects a driver’s overall ability to safely, efficiently, and comfortably operate a motor vehicle remains unclear.
2015-04-14
Technical Paper
2015-01-1430
Brian Gilbert, Joseph McCarthy, Ron Jadischke
Objectives: The analysis and modeling of vehicle crush in accident reconstruction has traditionally been based upon the use of linear crush-based, stiffness coefficients. Recent research has allowed for the calculation and implementation of non-linear crush coefficients. Through the use of Engineering Dynamics Corporation (EDC) accident reconstruction software Human-Vehicle-Environment (HVE), which contains the collision algorithm called DyMESH (DYnamic MEchanical SHell), these coefficients have increased the accuracy of predicted crash pulse data. Research on non-linear crush coefficients thus far has been limited to frontal impacts into rigid barriers. Side Impact tests are typically more complex than a frontal collision testing. One form of side impact tests involve a Moving Deformable Barrier (MDB) impacting a stationary subject vehicle at a crab angle of 26-27 degrees.
2015-04-14
Technical Paper
2015-01-0136
Ying Fan
Abstract In order to overcome the drawback that the traditional risk priority number method could not clearly make a risk priority sequence, a new analysis method of RPN was presented. Combined with loss costs, this method was based on FMEA. Several quantitative parameters such as servicing time and costs were introduced to replace the three parameters used in the traditional method. And it took loss costs caused by failure as the final risk priority number, instead of severity of effects, probability occurrence and difficulty detection. Finally, safety evaluation to work equipment and other critical systems of a forklift was processed as a case to illustrate this proposed method. The results showed that the results processed by the new method could be utilized to solve the problem that the RPN values couldn't be sorted.
2015-04-14
Technical Paper
2015-01-0137
Ying Fan
Abstract Accurate risk prioritizing is directly related to the effectiveness of risk management. To overcome the shortage of the single numerical evaluation value, aiming at improving the accuracy of risk factors, a new risk priority method was proposed based on geometric characteristics of triangular fuzzy number and Analytic Hierarchy Process (AHP). This method was established on the basis of the fuzzy description of risk factors from experts, after the risk evaluation system was established. Then the fuzzy description of risk was processed with AHP, and fuzzy weights of risk factors were obtained and calculated it by using the geometric characteristics of triangular fuzzy number. Finally, the detailed ranking of risk factors by severity, probability and detection of risk was obtained. The risk priority of forklift system was processed to analyze the feasibility of this method.
2015-04-14
Journal Article
2015-01-1481
Myles Wilson, David Aylor, David Zuby, Joseph Nolan
Abstract The Insurance Institute for Highway Safety (IIHS) evaluates autonomous emergency braking (AEB) systems as part of its front crash prevention (FCP) ratings. To prepare the test vehicles' brakes, each vehicle must have 200 miles on the odometer and be subjected to the abbreviated brake burnish procedure of Federal Motor Vehicle Safety Standard (FMVSS) 126. Other organizations conducting AEB testing follow the more extensive burnishing procedure described in FMVSS 135; Light Vehicle Brake Systems. This study compares the effects on AEB performance of the two burnishing procedures using seven 2014 model year vehicles. Six of the vehicles achieved maximum AEB speed reductions after 60 or fewer FMVSS 135 stops. After braking performance stabilized, the Mercedes ML350, BMW 328i, and Volvo S80 showed increased speed reductions compared with stops using brand new brake components.
2015-04-14
Journal Article
2015-01-1441
Yibing Shi, Guy Nusholtz
Abstract Two methods of assessing the similarity of a set of impact test signals have been proposed and used in the literature, which are cumulative variance-based and cross correlation-based. In this study, a normalized formulation unites these two approaches by establishing a relationship between the normalized cumulative variance metric (v), an overall similarity metric, and the normalized magnitude similarity metric (m) and shape similarity metric (s): v=1 − m · s. Each of these ranges between 0 and 1 (for the practical case of signals acquired with the same polarity), and they are independent of the physical unit of measurement. Under generally satisfied conditions, the magnitude similarity m is independent of the relative time shifts among the signals in the set; while the shape similarity s is a function of these.
2015-04-14
Journal Article
2015-01-1482
Bisheshwar Haorongbam, Anindya Deb, Clifford Chou
Abstract Hat-sections, single and double, made of steel are frequently encountered in automotive body structural components. These components play a significant role in terms of impact energy absorption during vehicle crashes thereby protecting occupants of vehicles from severe injury. However, with the need for higher fuel economy and for compliance to stringent emission norms, auto manufacturers are looking for means to continually reduce vehicle body weight either by employing lighter materials like aluminum and fiber-reinforced plastics, or by using higher strength steel with reduced gages, or by combinations of these approaches. Unlike steel hat-sections which have been extensively reported in published literature, the axial crushing behavior of hat-sections made of fiber-reinforced composites may not have been adequately probed.
2015-04-14
Journal Article
2015-01-1489
Raed E. El-jawahri, Tony R. Laituri, Agnes S. Kim, Stephen W. Rouhana, Para V. Weerappuli
Abstract Transfer or response equations are important as they provide relationships between the responses of different surrogates under matched, or nearly identical loading conditions. In the present study, transfer equations for different body regions were developed via mathematical modeling. Specifically, validated finite element models of the age-dependent Ford human body models (FHBM) and the mid-sized male Hybrid III (HIII50) were used to generate a set of matched cases (i.e., 192 frontal sled impact cases involving different restraints, impact speeds, severities, and FHBM age). For each impact, two restraint systems were evaluated: a standard three-point belt with and without a single-stage inflator airbag. Regression analyses were subsequently performed on the resulting FHBM- and HIII50-based responses. This approach was used to develop transfer equations for seven body regions: the head, neck, chest, pelvis, femur, tibia, and foot.
2015-04-14
Journal Article
2015-01-1595
Kristoffer Lundahl, Chih Feng Lee, Erik Frisk, Lars Nielsen
Rollover has for long been a major safety concern for trucks, and will be even more so as automated driving is envisaged to becoming a key element of future mobility. A natural way to address rollover is to extend the capabilities of current active-safety systems with a system that intervenes by steering or braking actuation when there is a risk of rollover. Assessing and forecasting the rollover is usually performed using rollover indices, which can be calculated either from lateral acceleration, lateral load transfer, or roll energy. Since these indices are evaluated based on different physical observations it is unclear how they can be compared and how well they reflect rollover events in different situations. In this paper we investigate the implication of the above mentioned rollover indices, in different critical maneuvers, for a heavy 8x4 twin-steer truck.
2015-04-14
Technical Paper
2015-01-0217
William Buller, Rini Sherony, Brian Wilson, Michelle Wienert
Abstract To reduce the number and severity of accidents, automakers have invested in active safety systems to detect and track neighboring vehicles to prevent accidents. These systems often employ RADAR and LIDAR, which are not degraded by low lighting conditions. In this research effort, reflections from deer were measured using two sensors often employed in automotive active safety systems. Based on a total estimate of one million deer-vehicle collisions per year in the United States, the estimated cost is calculated to be $8,388,000,000 [1]. The majority of crashes occurs at dawn and dusk in the Fall and Spring [2]. The data includes tens of thousands of RADAR and LIDAR measurements of white-tail deer. The RADAR operates from 76.2 to 76.8 GHz. The LIDAR is a time-of-flight device operating at 905 nm. The measurements capture the deer in many aspects: standing alone, feeding, walking, running, does with fawns, deer grooming each other and gathered in large groups.
2015-04-14
Journal Article
2015-01-0612
Weiguo Zhang, Zeyu Ma, Ankang Jin, James Yang, Yunqing Zhang
Abstract Nowadays, studying the human body response in a seated position has attracted a lot of attention as environmental vibrations are transferred to the human body through floor and seat. This research has constructed a multi-body biodynamic human model with 17 degrees of freedom (DOF), including the backrest support and the interaction between feet and ground. Three types of human biodynamic models are taken into consideration: the first model doesn't include the interaction between the feet and floor, the second considers the feet and floor interaction by using a high stiffness spring, the third one includes the interaction by using a soft spring. Based on the whole vehicle model, the excitation to human body through feet and back can be obtained by ride simulation. The simulation results indicate that the interaction between feet and ground exerts non-negligible effect upon the performance of the whole body vibration by comparing the three cases.
2015-04-14
Journal Article
2015-01-0319
Reena Kumari Behera, Jiji Gangadharan, Krishnan Kutty, Smita Nair, Vinay Vaidya
Pedestrian fatalities in road accidents are increasing exponentially. The insight shows a crucial need for coming up with a real time pedestrian detection system on vehicles. This paper presents a vision based pedestrian detection system. The methods available in literature are mostly classifier based that is applied at various image scales, which makes it inefficient for real time application. The presented algorithm is a novel method that accurately segments the pedestrian regions in real time. The fact that the pedestrians are always vertically aligned is taken into consideration. As a result, the edge image is scanned from bottom to top and left to right. Both the color and edge data is combined in order to form the segments. The segmentation is highly dependent on the edge map. Even a single pixel dis-connectivity would lead to incorrect segments. To improve this, a novel edge linking method is performed prior to segmentation.
2015-04-14
Technical Paper
2015-01-1428
Shane Richardson, Andreas Moser, Tia Lange Orton, Roger Zou
Currently techniques that can be used to evaluate and analyse lateral impact speeds of vehicle crashes with poles are based on measuring the deformation crush and using lateral crash stiffness data to estimate the impact speed. However, in some cases the stiffness data is based on broad object side impacts rather than pole impacts. The premise is that broad object side impact tests can be used for narrow object impacts; previous authors have identified the fallacy of this premise. Publicly available pole crash test data is evaluated. A range of simulated pole impact tests at various speeds and impact angles are conducted on validated publicly available Finite Element Vehicle models of a 1991 Ford Taurus, a 1994 Chevrolet C2500 and a 1997 Geo Metro (Suzuki Swift), providing a relationship between impact speed, crush depth and impact angle. This paper builds on previous publications and contains additional pole tests and new Finite Element Analyses.
2015-04-14
Journal Article
2015-01-1426
Drew A. Jurkofsky
Photogrammetry from images captured by terrestrial cameras and manned aircraft has been used for many years to model objects, create scale diagrams and measure distances for use in traffic accident investigation and reconstruction. Due to increasing capability and availability, Unmanned Aircraft Systems (UAS), including small UAS (SUAS), are becoming a valuable, cost effective tool for collecting overhead images for photogrammetric analysis. The metric accuracy of scale accident scene diagrams created from SUAS imagery has yet to be compared to conventional measurement methods, such as total station and laser measurement systems, which are widely used by public safety officials and private consultants. For this study, two different SUAS were used to collect overhead imagery for photogrammetric processing using PhotoModeler software.
2015-04-14
Technical Paper
2015-01-1432
Jeffrey Aaron Suway, Judson Welcher
Accident reconstruction experts are often asked to evaluate the visibility and conspicuity of objects in the roadway. It is common for some of these objects, and required by Federal Motor Vehicle Safety Standard (FMVSS) No. 108 for certain vehicles and trailers, to have red and white DOT-C2 retroreflective tape installed on several locations. Retroreflective tape is designed to reflect light back towards the light source, at the same entrance angle. FMVSS No. 108 has performance requirements for retroreflective tape at different entrance angles, up to 45 degree. The federal requirement for minimum performance of the retroreflective tape at 45 degrees is significantly less than the federal requirement for minimum performance of the retroreflective tape at 4 degrees. Additionally, the federal requirement for the minimum performance of white retroreflective tape is significantly different than the federal requirement for the minimum performance of red retroreflective tape.
2015-04-14
Technical Paper
2015-01-1429
Jeffrey Aaron Suway, Judson Welcher
Federal Motor Vehicle Safety Standard (FMVSS) No. 108 has requirements for retroreflective tape at different entrance angles, up to 45 degree. In the author’s preliminary research, all DOT-C2 retroreflective tape on the market is advertised as meeting and exceeding FMVSS No. 108 requirements. The author’s literature review revealed that there have been no peer-reviewed publications measuring the performance of commercially available DOT-C2 retroreflective tape. Therefore, without additional study, an accident reconstruction expert cannot know exactly how a specific type of compliant tape would perform, beyond the minimum federal requirements. Therefore, the authors have measured the performance of different types of retroreflective tape with a laboratory grade retroreflectometer. The authors attempted to study a range of popular, commercially available, DOT-C2 retroreflective tape. In this study, 3M 963, 3M 983, Grote, and Trucklite DOT-C2 retoreflective tape was used.
2015-04-14
Technical Paper
2015-01-1442
Wolfgang Sinz, Jörg Moser, Christoph Klein, Robert Greimel, Karsten Raguse, Class Middendorff, Christina Steiner
Precise three-dimensional dummy head trajectories during crash tests are very important for vehicle safety development. To determine precise trajectories with an accuracy of approximately 5 millimetres, three-dimensional video analysis is an approved method. Therefore the tracked body is to be seen on at least two cameras during the whole crash term, which is often not given (e.g. head dips into the airbag). This non-continuity problem of video analysis is surmounted by numerical integration of differential un-interrupted electrical rotation and acceleration sensor signals mounted into the tracked body. Problems of this approach are unknown sensor calibration errors and unknown initial conditions, which result in trajectory deviations above 10 centimetres.
2015-04-14
Technical Paper
2015-01-1455
Kenshi Torikai, Hitoshi Higuchi, Kazuhiro Seki
Airbags help mitigate direct hits. The passenger airbag has a vent structure discharging the internal gas such that a suitable airbag reaction force is obtained. Since the conventional vent structure is always open, the reaction force of such an airbag tends to fall when the contact timing (CT) is long. What prevents this drop in the airbag reaction force is a structure which closes the vent hole until contact to maintain the internal pressure and opens the vent hole after contact. However, variable vent structures are typically complicated and difficult to control due to the lid of the vent hole and a strap to pull the lid. We researched a simplified variable vent structure, investigating a “slit type” vent structure to reduce the complexity of conventional variable vent structures.
2015-04-14
Technical Paper
2015-01-1451
Anand Sai Gudlur, Theresa Atkinson
ABSTRACT The current study examined field data in order to document injury rates, injured body regions, and injury sources for persons seated in the second row of passenger vehicles. It was also intended to identify whether these varied with respect to age and restraint use in vehicles manufactured in recent years.Data from the 2007-2012 National Automotive Sampling System (NASS/CDS) was used to describe occupants seated in the second row of vehicles in frontal crashes. Injury plots, comparison of means and logistic regression analysis were used to identify factors associated with increased risk of injury. Restraint use reduced the risk of AIS ≥ 2 injury from approximately 1.8% to 5.8% overall. Seventy nine percent of the occupants in the weighted data set used either a lap and shoulder belt or child restraint system. The most frequently indicated injury source for persons with a MAIS ≥ 2 was “seat, back support”, across restraint conditions and for all but the youngest occupants.
2015-04-14
Technical Paper
2015-01-1465
Sho Nikaido, Shota Wada, Yasuhiro Matsui, Shoko Oikawa, Toshiya Hirose
1. Background and purpose There are various contributing factors to accidents of bicycles, it is considered that cyclists often do not observe the traffic regulation that requires cyclists to stop before a stop line at an intersection. As a countermeasure to this type of accident, cycling assist systems that activate a warning system for cyclists have been researched and developed. This assist system warns the cyclist about the danger of a collision. Such an assist system needs to provide a warning with appropriate timing. It is necessary to clarify cycling characteristics in developing a countermeasure for traffic accidents at an intersection without signals. The findings of this study can be used for the future construction of an assist system that will encourage cyclists to observe traffic regulations.
2015-04-14
Technical Paper
2015-01-1483
Anindya Deb, N Shivakumar, Clifford Chou
Rigid polyurethane (PU) foam finds wide applications as a lightweight material in impact safety design such as improving occupant safety in vehicle crashes. The two principal reacting compounds for formulating such a foam are variants of polyol and isocyanate. In the present study, an alternative mechanical engineering-based approach for determining, with confidence, the desirable ratio of reacting compounds for formulation of a rigid/crushable PU foam for mechanical applications is demonstrated. According to the present approach, PU foam samples are prepared by varying the mixing ratio over a wide range. The desirable mixing ratio is shown to be the one that optimizes key mechanical properties under compression such as total absorbed energy, specific absorbed energy and energy absorption efficiency.
2015-04-14
Technical Paper
2015-01-1459
Lotta Jakobsson, Magnus Björklund, Anders Axelson
Vertical accelerations can cause thoracic and lumbar spine injuries to a car occupant. Representative crashes potentially causing occupant vertical accelerations include; rollover events or free flying events when the car lands on its wheels, and run off road events when the car goes into the ditch and collides with an embankment from a crossing road. The spinal tolerances are dependent on occupant posture at time of impact which is an important factor with respect to limit of tolerances. Up to date, there is no standardized test method evaluating this occupant loading mechanism. The aim of this study was to develop test methods addressing vertical acceleration for car occupants and to evaluate countermeasures reducing the vertical loadings. Based on real world run off road crash investigations, representative test track methods were developed; including free flight before landing on the wheels and traveling in ditch impacting an embankment.
2015-04-14
Technical Paper
2015-01-1479
Adria Ferrer, Eduard Infantes
In September 2009 the National Highway Traffic Safety Administration (NHTSA) published a report that investigated the incidence of fatalities to belted non-ejected occupants in frontal crashes involving late-model vehicles. The report concluded that after exceedingly severe crashes, the largest number of fatalities occurred in crashes involving poor structural engagement between the vehicle and its collision partner, such as corner impacts, oblique crashes, or impacts with narrow objects. In response to these findings, NHTSA designed and developed a test procedure intended to mitigate the risk of injuries and fatalities related to motor vehicle crashes involving poor structural engagement. This research demonstrated that an offset impact between a moving deformable barrier (RMDB) and a stationary vehicle at a 15º angle can reproduce vehicle crush, occupant kinematics, and risk of injury seen in vehicle-to-vehicle crashes.
2015-04-14
Technical Paper
2015-01-1485
Jiri Kral, Theresa Kondel, Mark Morra, Stephen Cassatta, Peter Bidolli, Patrick Stebbins, Vikas Joshi
A new apparatus for testing modern safety belt systems was developed. Its design, dynamic behavior and test procedure are described. A number of tests have been conducted using this apparatus. These tests allowed identification of key performance parameters of pretensioners and load limiting retractors which are relevant to occupant protection in crash environment. Good test repeatability was observed, which allows comparison of different safety belt designs. The apparatus may be used for better specification and verification of safety belt properties on subsystem level as well as for validation of CAE models of safety belts used in simulations of occupant response to crash.
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