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Viewing 91 to 120 of 17295
2017-03-28
Journal Article
2017-01-0368
Ying Zhao, Fangwu Ma, Longfan Yang, Yueqiang Wang, Hongyu Liang
The conventional hood with single material and stiffener structural form conceals some limitations on pedestrian protection and lightweight, not satisfying the requirements of structural strength, pedestrian protection and lightweight contradictory with each other at the same time. In this paper, a novel type hood is proposed to develop sandwich structure using architected cellular material with negative Poisson's ratio (NPR) configuration based on the decoupling thought of structural strength and energy absorption. Core-layer aluminum alloy material with NPR is used to meet the requirement of impact energy absorption, inner and outer skin using carbon fiber is selected to achieve high structural stiffness needed. This paper starts from the relations between geometric parameters of core-layer architected cellular material and mechanical properties, on this basis, the optimal geometric parameters can be expected using the multiobjective optimization method.
2017-03-28
Technical Paper
2017-01-1473
Ling Zheng, Yinan Gao, Zhenfei Zhan, Yinong Li
Several surrogate models such as radial basis function and Kriging models are developed to speed the optimization design of vehicle body and improve the vehicle crashworthiness. The error analysis is used to investigate the accuracy of different surrogate models. Furthermore, the Kriging model is used to fit the model of B-pillar acceleration and foot well intrusion. The multiquadric radial basis function is used to fit the model of the entire vehicle mass. These models are further used to calculate the acceleration response in B-pillar, foot well intrusion and vehicle mass instead of the finite element model in the optimization design of vehicle crashworthiness. A multi-objective optimization problem is formulated in order to improve vehicle safety performance and keep its light weight. The particle swarm method is used to solve the proposed multi-objective optimization problem.
2017-03-28
Journal Article
2017-01-0015
Wolfgang Granig, Dirk Hammerschmidt, Hubert Zangl
Authors: DI(FH) Wolfgang Granig, Infineon Technologies Austria AG Dr. Dirk Hammerschmidt, Infineon Technologies Austria AG Dr. Hubert Zangl, Alpe-Adria University Klagenfurt Abstract: Functional safe products conforming the ISO26262 standard are getting more important for automotive applications wherein electronic takes more and more response for safety relevant operations. Consequently safety mechanisms are needed and implemented in order to reach defined functional safety targets. To prove their effectiveness diagnostic coverage provides a measurable quantity. A straight forward safety mechanism for sensor systems can be established by redundant signal paths measuring the same physical quantity and subsequently performing an independent output difference-check that decides if the data can be transmitted or an error message shall be sent.
2017-03-28
Journal Article
2017-01-0112
Mingming Zhao, Hongyan Wang, Xiao Xu, Yutong He
Rear-end accident is one of the most important collision modes in China, which often leads to severe accident consequences due to the high collision velocity. Autonomous Emergency Braking (AEB) System could perform emergency brake automatically in dangerous situation and mitigate the consequence. This study focused on the analysis of the rear-end accidents in China in order to discuss about the parameters of Time-to-Collision (TTC) of AEB and the potential effectiveness. A sample of 84 accidents was in-depth investigated and reconstructed, providing a comprehensive set of data describing the pre-crash matrix. Each accident in this sample is reconstructed and modeled numerically by the simulation tool PC-Crash. In parallel, a model representing the function of an AEB system has been established. This AEB system applies partial braking when the TTC ≤ TTC1 and full braking when the TTC ≤ TTC2.
2017-03-28
Journal Article
2017-01-1516
Daniel B. Honeycutt, Mesbah Uddin
Although, the implementation of lift-off prevention devices such as the NASCAR roof flaps have greatly reduced the frequency and severity of race vehicle aerodynamic lift-off incidents, airborne incidents still occur occasionally in motorsports. In many cases, contact with another vehicle contributes to the lift-off. Race vehicle aerodynamic lift-off incidents are analyzed and factors contributing to aerodynamic lift-off of various race vehicles are discussed in this paper. This is done by using aerodynamic lift data from wind tunnel testing for various NASCAR race vehicles, such as NASCAR stock cars and trucks, and sports car prototypes. The effectiveness of existing lift-off prevention measures and future trends in lift-off prevention are discussed.
2017-03-28
Technical Paper
2017-01-1468
Do Hoi KIm
Previous studies have dealt with the relationship between the injury criteria of dummies and vehicle drop during high-speed head on collisions. Ultimately, vehicle drops are found to worsen the injury criteria of dummies when exceeding 60mm during high-speed crashes. Also, vehicle drops affected the front side member of the vehicle body the most. The present study dealt with methods of improving vehicle drops by enhancing the connective structure of the front side member, the short gun, and the A pillar. Analyses on various vehicles confirm that arch-shaped front side members are an extremely important factor. Furthermore, if the short gun and A pillar are properly connected at the top of the arch shape on the front side member during crashes, the deformation energy of the vehicle could be converted to energy for lifting the A pillar lower. With a so-called body lift structure, BLS has been applied to the B/C segment vehicles of Hyundai and KIA.
2017-03-28
Technical Paper
2017-01-1360
John D. Bullough
Abstract Nighttime driving cannot be accomplished without vehicle headlighting. A growing body of evidence demonstrates the role of lighting on visual performance and in turn on nightttime driving safety in terms of crashes. Indirect impacts of lighting via comfort or other factors are less well understood, however. A two-part field study using real-world drivers of an instrumented vehicle was conducted to assess the potential role of oncoming headlight glare as a factor in driving behaviors that might be related to increased crash risks. In the first part of the study, drivers' behaviors when navigating through roadway intersections having different levels of crash risk were recorded in order to identify responses that were correlated with the risk level. In the second part, drivers were exposed to different levels of glare from oncoming headlights; several of the same risk-related behaviors identified in the first part of the study were exhibited.
2017-03-28
Technical Paper
2017-01-1353
Michael G. Leffert
Abstract This paper compares the material consumption and fire patterns which developed on four nearly identical compact sedans when each was burned for exactly the same amount of time, but with different wind speed and direction during the burns. This paper will also compare the effects of environmental exposure to the fire patterns on the vehicles. The burn demonstrations were completed at an outdoor facility in southeast Michigan on four late model compact sedans. The wind direction was controlled by placing the subject vehicle with either the front facing into the wind, or rear facing into the wind. Two of the burns were conducted when the average observed wind speed was 5-6kph and two of the burns were conducted at an average observed wind speed of 19kph.
2017-03-28
Technical Paper
2017-01-1380
Richard Young
Abstract Dingus and colleagues recently estimated the crash odds ratios (ORs) for secondary tasks in the Strategic Highway Research Program Phase 2 (SHRP 2) naturalistic driving study. Their OR estimate for hand-held cell phone conversation (Talk) was 2.2, with a 95% confidence interval (CI) from 1.6 to 3.1. This Talk OR estimate is above 1, contrary to previous estimates below 1. A replication discovered two upward biases in their analysis methods. First, for video clips with exposure to a particular secondary task, Dingus and colleagues selected clips not only with exposure to that task, but often with concurrent exposure to other secondary tasks. However, for video clips without exposure to that task, Dingus and colleagues selected video clips without other secondary tasks. Hence, the OR estimate was elevated simply because of an imbalanced selection of video clips, not because of risk from a particular secondary task.
2017-03-28
Technical Paper
2017-01-1370
Hiroyuki Hara, Masaaki Kawauchi, Masayuki Katayama, Noriyuki Iwamori
Abstract Driving is an action that depends strongly on visual information. For displays in the cockpit, a combination of “ease of viewing” to inform the driver of danger early and “annoyance reduction” to avoid drops in the driver’s perception is needed. In this study, we tried to capture “ease of viewing” and “annoyance” in one fixed-quantity indicator. We took up a Camera Monitor System (CMS) as the subject and analyzed the effect that annoyance with the display used in CMSs has on driving behavior. Based on our analysis, we hypothesize that evaluating carelessness in viewing behavior is related evaluating to annoyance. Next, we chose a Detection Response Task (DRT) technique as a method to evaluate driving behavior influenced by this annoyance.
2017-03-28
Technical Paper
2017-01-1369
Abtine Tavassoli, Sam Perlmutter, Dung Bui, James Todd, Laurene Milan, David Krauss
Abstract Vision plays a key role in the safe and proper operation of vehicles. To safely navigate, drivers constantly scan their environments, which includes attending to the outside environment as well as the inside of the driver compartment. For example, a driver may monitor various instruments and road signage to ensure that they are traveling at an appropriate speed. Although there has been work done on naturalistic driver gaze behavior, little is known about what information drivers glean while driving. Here, we present a methodology that has been used to build a database that seeks to provide a framework to supply answers to various ongoing questions regarding gaze and driver behavior. We discuss the simultaneous recording of eye-tracking, head rotation kinematics, and vehicle dynamics during naturalistic driving in order to examine driver behavior with a particular focus on how this correlates with gaze behavior.
2017-03-28
Technical Paper
2017-01-1365
Michael Larsen
Abstract Vehicle certification requirements generally fall into 2 categories: self-certification and various forms of type approval. Self-certification requirements used in the United States under Federal Motor Vehicle Safety Standards (FMVSS) regulations must be objective and measurable with clear pass / fail criteria. On the other hand, Type Approval requirements used in Europe under United Nations Economic Commission for Europe (UNECE) regulations can be more open ended, relying on the mandated 3rd party certification agency to appropriately interpret and apply the requirements based on the design and configuration of a vehicle. The use of 3rd party certification is especially helpful when applying regulatory requirements for complex vehicle systems that operate dynamically, changing based on inputs from the surrounding environment. One such system is Adaptive Driving Beam (ADB).
2017-03-28
Technical Paper
2017-01-1364
Kashif Ali, Vikas Kumar, Virat Kalra
Abstract Vehicle occupant packaging and interior and exterior body design determine the overall visibility that the driver of the vehicle has. Visibility is also dependent on technological features inside and outside the passenger cell like proximity sensors and cameras etc. The focus of this research is to find and analyze the visibility percentages, blind spot angles and blind spot areas using statistical data both individually and as vehicle class put together in order to justify the need for standardization of basic visibility enhancing aids. This study has an added significance considering the Indian road transportation statistics. On an average, 16 people die every hour due to road accidents in India. The aim is to focus on cases that affect visibility in low speed driving, coasting and reversing that causes loss to public and private property.
2017-03-28
Journal Article
2017-01-1352
David Gardiner
The North American light duty vehicle fleet includes a substantial number of Flexible Fuel Vehicles (FFVs) which can operate on fuels containing up to 85% denatured ethanol. When these vehicles are operated in climatic regions with very cold winter temperatures, the portion of denatured ethanol in the fuel is normally reduced to well below 85% in order to improve fuel volatility. Both the U.S and Canadian standards for automotive spark ignition fuels include seasonal volatility requirements whose purpose includes the creation of fuel tank vapour space mixtures that are too rich to be flammable. However, there is limited information available about the actual temperature limits of flammability for real-world high ethanol (“E85”) and low ethanol (“E10”) blends, and the minimum vapour pressure values needed to achieve the desired temperature limits.
2017-03-28
Journal Article
2017-01-1351
Vamshi Korivi, Steven McCormick, Steven Hodges
The US Army Tank Automotive Research, Development and Engineering Center (TARDEC) developed a unique physics based modeling & simulation (M&S) capability using Computational Fluid Dynamics (CFD) techniques to optimize Automatic Fire Extinguishing System (AFES) designs and complement vehicle testing for both occupied and unoccupied spaces of military ground vehicles. The modeling technique developed here is based on reduced global kinetics for computational efficiency and is applicable to fire suppressants that are being used in Army vehicles namely, bromotrifluoromethane (Halon 1301), heptafluoropropane (HFC-227ea, trade name FM200), sodium bicarbonate (SBC) powder, water + potassium acetate mixture, and pentafluoroethane (HFC-125). These CFD simulations are performed using High Performance Computers (HPC) that enable the Army to assess these designs inexpensively in a virtual world that is crucial for vehicle and soldier protection in this complex world.
2017-03-28
Technical Paper
2017-01-1400
Keyu Qian, Gangfeng Tan, Renjie Zhou, Binyu Mei, Wanyang XIA
Downhill mountain road is the accident prone section because of its complexity and variety. Drivers rely more on driving experience and it is very easy to cause traffic accidents due to negligence or failure of judgment. Traditional active safety systems, such as ABS, subjects to the driver's visual feedback, can’t fully guarantee the downhill driving safety in complex terrain environment. This study combines the characteristics of vehicle dynamics and geographic information, giving drivers safety speed in advance to reduce traffic accidents due to driver's miscarriage of justice or brake overheating and enhance the safety of vehicles in the downhill. Firstly, establish the commercial vehicle driving model, main brake and auxiliary brake model, and study the characteristics of the driving conditions under the change of slope length and slope. Gather the real-time information of the vehicle, such as vehicle weight, speed, gear and engine speed to calculate the vehicle braking torque.
2017-03-28
Technical Paper
2017-01-1399
Bin Wu, Xichan Zhu, Jianping Shen, Xuejun Cang, Lin li
A driver steering model for emergency lane change based on the China naturalistic driving data is proposed in this paper. The steering characteristic of three phases is analyzed. Using the steering primitive fitting by Gaussian function, the steering behaviors in collision avoidance and lateral movement phases can be described, and the stabilization steering principle of yaw rate null is found. Based on the steering characteristic, the near and far aim point used in steering phases is analyzed. Using the near and far aim point correction model, a driver steering model for emergency lane change is established. The research results show that the driver emergency steering model proposed in this paper performs well when explaining realistic steering behavior, and this model can be used in developing the ADAS system.
2017-03-28
Journal Article
2017-01-1415
John D. Struble, Donald E. Struble
Crash tests of vehicles by striking deformable barriers are specified by Government programs such as FMVSS 214, FMVSS 301 and the Side Impact New Car Assessment Program (SINCAP). Such tests result in both crash partners absorbing crush energy and moving after separation. Compared with studying fixed rigid barrier crash tests, the analysis of the energy-absorbing behavior of the vehicle side (or rear) structure is much more involved. Described in this paper is a method by which analysts can use such crash tests to determine the side structure stiffness characteristics for the specific struck vehicle. Such vehicle-specific information allows the calculation of the crush energy for the particular side-struck vehicle during an actual collision – a key step in the reconstruction of that crash. Based on fundamental principles of physics and engineering, this method provides transparency in the calculation of side structure stiffness parameters for the particular vehicle of interest.
2017-03-28
Technical Paper
2017-01-1413
Nathan A. Rose, Neal Carter, David Pentecost, Alireza Hashemian
This paper investigates the dynamics of single-vehicle motorcycle crashes that occur on curves and identifies rider actions that contribute to causing these crashes. Physical evidence and physical principles that would enable a reconstructionist to determine when these actions are present in a particular crash are identified. The investigation is carried out by analyzing video footage of 10 motorcycle crashes that all occurred on a particular curve (Edwards Corner) on a section of the Mulholland Highway called “The Snake.” This section of highway is located in the Santa Monica Mountains of California. All of the video footage of these crashes was captured by a videographer who regularly takes video of motorcyclists traversing this curve and posts crash videos on YouTube. To aid evaluation of these crashes, the authors mapped Edwards Corner using both a Sokkia total station and a Faro laser scanner.
2017-03-28
Technical Paper
2017-01-1407
Helene G. Moorman, Andrea Niles, Caroline Crump, Audra Krake, Benjamin Lester, Laurene Milan, Christy Cloninger, David Cades, Douglas Young
Lane Departure Warning (LDW) systems, along with other types of Advanced Driver Assistance Systems (ADAS), are becoming more common in passenger vehicles, with the general aim of improving driver safety through automation of various aspects of the driving task. Drivers have generally reported satisfaction with ADAS with the exception of LDW systems, which are often rated poorly or even deactivated by drivers. One potential contributor to this negative response may be an increase in the cognitive load associated with lane-keeping when LDW is in use. The present study sought to examine the relationship between LDW, lane-keeping behavior, and concurrent cognitive load, as measured by performance on a secondary task. Participants drove a vehicle equipped with LDW in a demarcated lane on a closed-course test track with and without the LDW system in use over multiple sessions.
2017-03-28
Technical Paper
2017-01-1417
Enrique Bonugli, Richard Watson, Mark Freund, Jeffrey Wirth
This paper reports on additional testing conducted using the test device described by Bonugli et al. (2014-01-1991). The method utilized quasi-static loading of bumper systems and other vehicle components to measure their force-deflection properties. Corridors on the force-deflection plots, for various vehicle combinations, were determined to define the system stiffness of the combined vehicle systems. Loading path and peak force measurements can then be used to evaluate the impact severity for low speed collisions in terms of delta-v and acceleration. The additional tests refine the stiffness corridors, previously published, which cover a wide range of vehicle types and impact configurations. The analysis of the collision models the compression phase of a low speed collision as a spring, the spring characteristics defined by the force-deflection corridors. This is followed by a linear rebound phase based on published restitution values.
2017-03-28
Journal Article
2017-01-1416
B. Nicholas Ault, Daniel E. Toomey
Reconstruction of passenger vehicle accidents involving side impacts with narrow objects has traditionally been approached using side stiffness coefficients derived from moveable deformable barrier tests or regression analysis using the maximum crush in available lateral pole impact testing while accounting for vehicle test weight. Current Lateral Impact New Car Assessment Program (LINCAP) testing includes 20 mph oblique lateral pole impacts. This test program often incorporates an instrumented pole so the force between the vehicle and pole at several elevations along the vehicle - pole interface is measured. Force-Displacement (F-D) characteristics of vehicle structures were determined using the measured impact force and calculated vehicle displacement from on-board vehicle instrumentation.
2017-03-28
Journal Article
2017-01-1475
Saeed Barbat, Xiaowei Li
On December 2015, The National Highway Traffic Safety Administration (NHTSA) published its proposal to implement U.S New Car Assessment Program (NCAP) changes beginning in 2019 model year. The proposal included a new frontal oblique impact (OI) test protocol which comprises of a new Oblique Moving Deformable Barrier (OMDB), new THOR 50th% male dummy, and a new test configuration? An OMDB of 2,486Kg impacts a stationary target vehicle at a speed of 90Kph at an angle of 15 degrees with a 35% barrier overlap. In vehicle-to-vehicle collisions, the lighter weight vehicle experience higher velocity change, thereby, occupants in the lighter vehicle experience higher injury risk. This paper describes the analyses of a 31 OI tests conducted by NHTSA, in which the target vehicles used were of different sizes and weight distribution ranging between 1034Kg-2624Kg. Deformation Energy (DE) in the OMDP was calculated from the honeycomb deformation and stiffness.
2017-03-28
Journal Article
2017-01-1432
Tadasuke Katsuhara, Yoshiki Takahira, Shigeki Hayashi, Yuichi Kitagawa, Tsuyoshi Yasuki
This paper discusses mechanisms of spine fracture during racecar crash, and investigates possible modifications to the seat and driver restraint system to help reduce spine fracture risk. This study focused on an accident during the World Endurance Championship in which a driver sustained bony spine fractures at T11 and T12 as the racecar collided against the tire wall. Finite element (FE) simulations were analyzed to understand the spinal fracture mechanism, the driver kinematics and interactions between the driver and the seat/restraint system. This FE model incorporated the Total Human Model for Safety (THUMS) scaled to the driver size, a model of the detailed racecar cockpit and a model of the seat/restraint systems. A frontal impact deceleration pulse was applied to the cockpit model. In the simulation, the driver torso moved forward under the shoulder belt and the pelvis was restrained by the crotch belt and the front of the seat cushion.
2017-03-28
Journal Article
2017-01-1450
Daniel Perez-Rapela, Jason Forman, Haeyoung Jeon, Jeff Crandall
Current state-of-the-art vehicles implement pedestrian protection features that rely on pedestrian detection sensors and algorithms to trigger when impacting a pedestrian. During the development phase, the vehicle must “learn” to discriminate pedestrians from the rest of potential impacting objects. Part of the training data used in this process is often obtained in physical tests utilizing legform impactors whose external biofidelity is still to be evaluated. This study uses THUMS as a reference to assess the external biofidelity of the most commonly used impactors (Flex-PLI, PDI-1 and PDI-2). This biofidelity assessment was performed by finite element simulation measuring the bumper beam forces exerted by each surrogate on a sedan and a SUV. The bumper beam was divided in 50 mm sections to capture the force distribution in both vehicles. This study, unlike most of the pedestrian-related literature, examines different impact locations and velocities.
2017-03-28
Journal Article
2017-01-1445
Kevin Pline, Derek Board, Nirmal Muralidharan, Srinivasan Sundararajan, Eric Eiswerth, Katie Salciccioli, Noelle Baker
In 2011, Ford Motor Company introduced the first rear seat inflatable belts in Ford Explorer. Interaction of rear inflatable seat belts with child restraint systems (CRS) when it is used to install a CRS or used in conjunction with belt position booster is an important consideration. A comprehensive series of frontal impact sled tests, using a standardized test method, was conducted to compare the performance of a CRS installed using an inflatable seat belt to the identical CRS installed using a standard lap/shoulder belt. The study included rear facing only CRS, both with and without bases, from several CRS manufacturers in the North American CRS market. CRABI 12 month old or Hybrid III 3 year old anthropomorphic test devices (ATD) were restrained in the CRS. The assessment included comparisons of ATD/CRS responses and kinematics, and CRS structural integrity.
2017-03-28
Journal Article
2017-01-1472
Niels Pasligh, Robert Schilling, Marian Bulla
Rivets, especially self-piercing rivets (SPR), are one primary joining technology for vehicles using aluminum. SPR are mechanical joining elements that are used to connect sheets to create a structure to build a body in white (BiW). To ensure the structural performance of a vehicle in crash load cases it is necessary to describe physical occurring failure modes under overloading conditions in simulations. One failure mode is joint separation which need to be precisely predicted by a crash simulation. Within crash simulations a detailed analysis of a SPR joint and its process history would require a very high computational effort. The conflict between a detailed SPR joint and a macroscopic vehicle model need to solved by developing an approach that can handle an accurate macroscopic prediction of SPR behavior with a defined strength level with less computational effort. One approach is using a cohesive material model for a SPR connection.
2017-03-28
Journal Article
2017-01-1463
Xianping Du, Feng Zhu, Clifford C. Chou
A new design methodology based on data mining theory has been proposed and used in the vehicle crashworthiness design. The method allows exploring the big crash simulation dataset to discover the underlying complicated relationships between response and design variables, and derive design rules based on the structural response to make decisions towards the component design. An S-shaped beam is used as an example to demonstrate the performance of this method. A large amount of simulations are conducted and the results form a big dataset. The dataset is then mined to build a decision tree. Based on the decision trees, the interrelationship among the geometric design variables are revealed, and then the design rules are derived to produce the design cases with good energy absorbing capacity. The accuracy of this method is verified by comparing the data mining model prediction and simulation data.
2017-03-28
Journal Article
2017-01-1465
William R. Bussone, Joseph Olberding, Michael Prange
At present, SAE J211 provides no definitive guidance as to the appropriate procedures for filtering angular rate sensor data prior to differentiation into angular acceleration data, especially for very short duration or impact data. Accordingly, a 3-2-2-2 array of linear accelerometers and a triaxial angular rate sensor were mounted into a Hybrid III 50th percentile male ATD headform and compared in a variety of impact events. An appropriate low-pass digital filter cutoff frequency for differentiating the angular rate sensor data into angular accelerations was sought via residual analysis in accordance with current SAE J211 guidelines to find appropriate cutoff frequencies which would best match the angular acceleration data measured by the 3-2-2-2 array, which is the present gold standard.
2017-03-28
Journal Article
2017-01-0118
Yang Wang, Ankit Goila, Rahul Shetty, Mahdi Heydari, Ambarish Desai, Hanlong Yang
Regarding safety, obstacle avoidance has been considered as one of the most important features among ADAS systems for ground vehicles. However, the implementation of obstacle avoidance functions to commercial vehicles are still under progress. In this paper, we demonstrate a complete process of obstacle avoidance strategy for unmanned ground vehicle and has implemented the strategy on the self-developed Arduino based RC Car. In this process, the sensor LIDAR was employed to detect the obstacles on the fore-path. Based on the measured radar data, an optimized path would be automatically generated with accommodation of current car position, obstacle locations, car operation capability and global environmental restrictions. The path planning is updated in real time while new or changing obstacles being detected. The Arduino provides required control inputs to the RC Car to follow the pre-planned path and self-positioned by the observed obstacles data.
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