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Viewing 121 to 79 of 79
2016-04-05
Journal Article
2016-01-1479
Gray Beauchamp, David Pentecost, Daniel Koch, Nathan Rose
Abstract Tire mark striations are discussed often in the literature pertaining to accident reconstruction. The discussions in the literature contain many consistencies, but also contain disagreements. In this article, the literature is first summarized, and then the differences in the mechanism in which striations are deposited and interpretation of this evidence are explored. In previous work, it was demonstrated that the specific characteristics of tire mark striations offer a glimpse into the steering and driving actions of the driver. An equation was developed that relates longitudinal tire slip (braking) to the angle of tire mark striations [1]. The longitudinal slip equation was derived from the classic equation for tire slip and also geometrically. In this study, the equation for longitudinal slip is re-derived from equations that model tire forces.
2016-04-05
Technical Paper
2016-01-1480
Jakub Zebala, Wojciech Wach, Piotr Ciępka, Robert Janczur
Abstract This article presents the results of an analysis of the yaw marks left by a car with normal pressure in all tires and then normal pressure in three tires and zero in one rear tire. The analysis is a continuation of research on influence of reduced tire pressure on car lateral dynamics in a passing maneuver, discussed in the SAE paper No. 2014-01-0466. Preliminary analysis of yaw marks has shown, that a wheel with zero pressure deposits a yaw mark whose geometry differs from the yaw mark made by a wheel with normal pressure based on which we could calculate: critical speed, slip angle and longitudinal wheel slip. The aim of the presented research was to analyze the yaw marks left by car with zero pressure in one rear wheel in order to check the possibility of determining the vehicle critical speed, slip angle and longitudinal wheel slip. It was reached by performing bench and road tests during which the vehicle motion parameters were recorded using GPS Data Logging System.
2016-04-05
Technical Paper
2016-01-1481
Gary A. Davis, Abhisek Mudgal
Abstract A continuing topic of interest is how to best use information from Event Data Recorders (EDR) to reconstruct crashes. If one has a model which can predict EDR data from values of the target variables of interest, such as vehicle speeds at impact, then in principle one can invert this model to estimate the target values from EDR measurements. In practice though this can require solving a system of nonlinear equations and a reasonably flexible method for carrying this out involves replacing the inverse problem with nonlinear least-squares (NLS) minimization. NLS has been successfully applied to two-vehicle planar impact crashes in order to estimate impact speeds from different combinations of EDR, crush, and exit angle measurements, but an open question is how to assess the uncertainty associated with these estimates. This paper describes how Markov Chain Monte Carlo (MCMC) simulation can be used to quantify uncertainty in planar impact crashes.
2016-04-05
Technical Paper
2016-01-1473
Orion P. Keifer, Bradley Reckamp, Charles Moody, Anthony Timpanaro
Abstract Evaluation of the severity of low speed motor vehicle crashes has been the subject of significant research for more than 25 years. These crashes typically result in little if any damage to the vehicles involved and therefore the ability to determine the threshold of damage would be very useful in analysis of such cases. One such threshold, which has been used by accident reconstructionists, is the manufacturer’s published bumper rating in compliance with Federal Motor Vehicle Safety Standards (FMVSS) for vehicle bumpers. The rationale is that if there is any damage to the bumper system of the vehicle in question, the impact must have had a severity greater than the rated bumper speed. This paper examines the FMVSS bumper standards upon which the published bumper ratings are reportedly in compliance, historical low speed testing damage results, and engineering considerations of bumper damage in low speed impacts.
2016-04-05
Technical Paper
2016-01-1474
Edward C. Fatzinger, Tyler L. Shaw, Jon B. Landerville
Abstract Six electronic needle-display speedometers from five different manufacturers were tested in order to determine the behavior of the gauges following a power interruption and impact. Subject motorcycles were accelerated to pre-determined speeds, at which point the speedometer wiring harness was disconnected. The observed results were that the dial indicator would move slightly up, down, or remain in place depending on the model of the speedometer. The observed change of indicated speed was within +/- 10 mph upon power loss. Additionally, the speedometers were subjected to impact testing to further analyze needle movement due to collision forces. Speedometers were attached to a linear drop rail apparatus instrumented with an accelerometer. A minimum acceleration due to impact which could cause needle movement was measured for each speedometer assembly.
2016-04-05
Technical Paper
2016-01-1475
Toby Terpstra, Tilo Voitel, Alireza Hashemian
Abstract Video and photo based photogrammetry software has many applications in the accident reconstruction community including documentation of vehicles and scene evidence. Photogrammetry software has developed in its ease of use, cost, and effectiveness in determining three dimensional data points from two dimensional photographs. Contemporary photogrammetry software packages offer an automated solution capable of generating dense point clouds with millions of 3D data points from multiple images. While alternative modern documentation methods exist, including LiDAR technologies such as 3D scanning, which provide the ability to collect millions of highly accurate points in just a few minutes, the appeal of automated photogrammetry software as a tool for collecting dimensional data is the minimal equipment, equipment costs and ease of use.
2016-04-05
Journal Article
2016-01-1477
Pamela D'Addario, Ken Iliadis, Gunter Siegmund
Abstract The ability to accurately calculate a snowmobile’s speed based on measured track marks in the snow is important when assessing a snowmobile accident. The characteristics and length of visible snowmobile track marks were documented for 41 locked-track braking tests and 38 rolldown tests using four modern snowmobiles on a groomed/packed snow surface. The documented track mark lengths were used to quantify the uncertainty associated with using track mark length to estimate initial speed. Regression models were developed for both data sets. The regression model of the locked-track tests revealed that using an average deceleration of 0.36g over the length of the locked track mark provides a good estimate of the best-fit line through the data, with the upper and lower 95th percentile prediction interval bounds best represented by using deceleration rates of 0.23g and 0.52g respectively.
2016-04-05
Technical Paper
2016-01-1469
Craig Luker
High image quality video surveillance systems have proliferated making it more common to have collision-related video footage that is suitable for detailed analysis. This analysis begins by using variety of methods to reconstruct a series of positions for the vehicle. If the frame rate is known or can be estimated, then the average travel speed between each of those vehicle positions can be found. Unfortunately with video surveillance systems, the frame rates are typically low and the vehicle may be hidden from view for multiple frames. As a result there are often relatively large time steps between known vehicle positions and the average speed between known positions becomes less useful. The method outlined here determines the instantaneous speed and acceleration time history of the vehicle that was required for it to arrive at the known positions, at the known times.
2016-04-05
Technical Paper
2016-01-1470
Nathan A. Rose, Neal Carter, Gray Beauchamp
Abstract Calculating the speed of a yawing and braked vehicle often requires an estimate of the vehicle deceleration. During a steering induced yaw, the rotational velocity of the vehicle will typically be small enough that it will not make up a significant portion of the vehicle’s energy. However, when a yaw is impact induced and the resulting yaw velocity is high, the rotational component of the vehicle’s kinetic energy can be significant relative to the translational component. In such cases, the rotational velocity can have a meaningful effect on the deceleration, since there is additional energy that needs dissipated and since the vehicle tires can travel a substantially different distance than the vehicle center of gravity. In addition to the effects of rotational energy on the deceleration, high yaw velocities can also cause steering angles to develop at the front tires. This too can affect the deceleration since it will influence the slip angles at the front tires.
2016-04-05
Technical Paper
2016-01-1471
Anthony Timpanaro, Charles Moody, Wesley Richardson, Bradley Reckamp, Orion Keifer
Abstract It is well known that older vehicles’ headlight assemblies degrade with exposure to the elements and can become cloudy or crazed. It is also known that the degradation decreases the amount of useful light projected forward, which can drastically reduce night time or down-road visibility. Testing has been performed to measure the available light projected by old degraded headlamp assemblies and new replacement assemblies, to quantify the decrease in emitted light caused by the degradation. The work has been extended to quantify the improvement in available light when the degraded lenses are treated with commercially available restoration products. Five different vehicle headlamp assemblies representing four different manufacturers were tested measuring the illumination at a given distance with a modified Extech® illuminance meter.
2016-04-05
Technical Paper
2016-01-1472
Dietmar Otte, Martin Urban, Heiko Johannsen
Abstract Estimating the potential benefit of advanced safety systems by simulation has become increasingly important during the last years. All over the world OEMs and suppliers carry out benefit estimations by simulations via computer models. Such simulations should, of course, be based on real world scenario such as the pre-crash phase of real world accidents. Several methodologies for building up accident scenarios have been developed in the past. This paper shows a new method for generating pre-crash scenarios directly from the reconstruction of the accident by using the software PC-Crash1. The new method was developed by the Medical University Hannover (MHH) and the Fraunhofer Institute for Transportation Dresden (Fraunhofer IVI). It is based on transferring all information (participant-, vehicle-, environment- and motion-data) from the reconstruction file into a scenario-database.
2016-04-05
Technical Paper
2016-01-1465
John Zolock, Carmine Senatore, Ryan Yee, Robert Larson, Brian Curry
Abstract As a result of the development of Event Data Recorders (EDR) and the recent FMVSS regulation 49 CFR 563, today’s automobiles provide a limited subset of electronic data measurements of a vehicle’s state before and during a crash. Prior to this data, the only information available about the vehicle movements before or during a collision had come from physical evidence (e.g. tire marks), witnesses, aftermarket camera systems on vehicles, and ground-based cameras that were monitoring vehicle traffic or used for security surveillance. Today’s vehicles equipped with Advanced Driver Assistance Systems (ADAS) have vehicle-based sensors that measure information about the environment around a vehicle including other vehicles, pedestrians, and fixed wayside objects.
2016-04-05
Technical Paper
2016-01-1466
Bradley C. Reckamp, Charles Moody, Anthony Timpanaro, Orion Keifer
Abstract A common low speed motor vehicle collision scenario occurs in heavy traffic situations between two or more vehicles which were stopped in traffic prior to the collision. While information regarding the pre-collision spacing of the involved vehicles can be very useful to an accident reconstructionist, witness perceptions and statements regarding the distance between the stopped vehicles, prior to the collision, can be inaccurate. Physical evidence regarding precollision spacing is also unavailable in most cases. A study was conducted of several selected intersections in three major metropolitan areas in the United States of America. Publicly available aerial photography, rectified and scaled, was used to perform a statistical analysis of the distance between stopped passenger vehicles at busy traffic signalized intersections.
2016-04-05
Technical Paper
2016-01-1467
Neal Carter, Alireza Hashemian, Nathan A. Rose, William T.C. Neale
Abstract Improvements in computer image processing and identification capability have led to programs that can rapidly perform calculations and model the three-dimensional spatial characteristics of objects simply from photographs or video frames. This process, known as structure-from-motion or image based scanning, is a photogrammetric technique that analyzes features of photographs or video frames from multiple angles to create dense surface models or point clouds. Concurrently, unmanned aircraft systems have gained widespread popularity due to their reliability, low-cost, and relative ease of use. These aircraft systems allow for the capture of video or still photographic footage of subjects from unique perspectives. This paper explores the efficacy of using a point cloud created from unmanned aerial vehicle video footage with traditional single-image photogrammetry methods to recreate physical evidence at a crash scene.
2016-04-05
Technical Paper
2016-01-1370
Vali Farahani, Salamah Maaita, Aditya Jayanthi
Abstract During the course of automobile Instrument Panel (IP) design development, the occupant head impact CAE simulation on IP are routinely performed to validate FMVSS201 requirements. Based on FMVSS201 requirements, the potential head impact zones on the IP are first identified. Then, the head impact zones are used to locate the various target points that must be impacted on IP. Once the critical target locations on IP are chosen, there are several computational steps that are required to calculate impact angles and head form (HF) center of rotation in reference to target points. Then, CAE engineer performs a repetitive process that involves positioning each individual HF with proper impact angle, assigning initial velocity to HF, and defining surface contacts within the finite element model (FEM). To simplify these lengthy manual steps, a commercially available software HyperMesh® CAE software tool is used to automate these steps.
2016-04-05
Journal Article
2016-01-1373
Emad Sadeghipour, Erich Josef Wehrle, Markus Lienkamp
Abstract Global emission targets and high fuel costs encourage manufacturers to produce ultralight vehicles. This and the low range of electric cars have resulted in new vehicle concepts and reuse of the quadricycles classification for microcars in Europe.
2016-04-05
Technical Paper
2016-01-1424
Yi G. Glaser, Robert E. Llaneras, Daniel S. Glaser, Charles A. Green
Abstract Partially automated driving involves the relinquishment of longitudinal and/or latitudinal control to the vehicle. Partially automated systems, however, are fallible and require driver oversight to avoid all road hazards. Researchers have expressed concern that automation promotes extended eyes-off-road (EOR) behavior that may lead to a loss of situational awareness (SA), degrading a driver’s ability to detect hazards and make necessary overrides. A potential countermeasure to visual inattention is the orientation of the driver’s glances towards potential hazards via cuing. This method is based on the assumption that drivers are able to rapidly identify hazards once their attention is drawn to the area of interest regardless of preceding EOR duration. This work examined this assumption in a simulated automated driving context by projecting hazardous and nonhazardous road scenes to a participant while sitting in a stationary vehicle.
2016-04-05
Journal Article
2016-01-1414
Shigeyoshi Hiratsuka, Shinichi Kojima, Nobuyuki Shiraki, Kazunori Higuchi, Toshihiko Tsukada, Keiichi Shimaoka, Kazuya Asaoka, Sho Masuda, Kazuhiko Nakashima
Abstract We investigated a lighting method that supports pedestrian perception by vehicle drivers. This lighting method makes active use of visual characteristics such as the spatio-temporal frequency of contrast sensitivity. Using reasonable parameter values derived from preliminary experiments using a Campbell-Robson chart, we determined a suitable lighting pattern that improves the driver's pedestrian perception. In order to assess the influence of visual characteristics on a reaction-time-dependent task, such as pedestrian perception in nighttime, tests were performed in the target environment, the results of which validated the proposed method.
2016-04-05
Technical Paper
2016-01-1417
Toshinao Fukui, Kazuhiko Nakamoto, Hiroyuki Satake
Abstract The use of a head-up display (HUD) system has become popular recently, as it can provide feedback information at a position easily seen by the driver. However, the outline of the HUD bezel often reflects on the windshield of a HUD equipped vehicle. This phenomenon occurs when the sun is at a high position and reflects off the top of the instrument panel and the front view is dark. For this reason, it can occur when driving on asphalt paved roads, causing annoyance to the driver. Under fixed environmental conditions, the vehicle based factors that influence the annoyance caused by reflected boundary lines are the position of the reflection, line thickness, and the contrast of the reflected boundary line. These can be represented by the conspicuity of a striped pattern (contrast sensitivity function). In previous research in 1991, M. S. Banks et al. studied a contrast sensitivity function that included the factors stated above.
2016-04-05
Technical Paper
2016-01-1420
Shinichi Kojima, Shigeyoshi Hiratsuka, Nobuyuki Shiraki, Kazunori Higuchi, Toshihiko Tsukada, Keiichi Shimaoka, Kazuya Asaoka, Sho Masuda, Kazuhiko Nakashima
Abstract This study aims at the development of a projection pattern that is capable of shortening the time required by a driver to perceive a pedestrian at night when a vehicle’s high beams are utilized. Our approach is based on the spatio-temporal frequency characteristics of human vision. Visual contrast sensitivity is dependent on spatiotemporal frequency, and maximum contrast sensitivity frequency varies depending on environmental luminance. Conventionally, there are several applications that utilize the spatio-temporal frequency characteristics of human vision. For example, the National Television System Committee (NTSC) television format takes into consideration low-sensitivity visual characteristics. In contrast, our approach utilizes high-sensitivity visual characteristics based on the assumption that the higher contrast sensitivity of spatio-temporal frequencies will correlate more effectively with shorter perception times.
2016-04-05
Technical Paper
2016-01-1412
Takeshi Hamaguchi, Satoshi Inoue, Shigeyuki Kimura, Terumasa Endo
Abstract In driver-focused vehicle development, driver workload is generally evaluated subjectively, with physiological, psychological, and behavioral indexes used to quantify and substantiate the subjective rating. In contrast, a model of driver behavior expresses the driver’s behavioral characteristics which make it possible to estimate how the driver will incorporate information into vehicle operation. Therefore, it is presumed to be capable of estimating the internal state of a driver. Conventionally, a model of driver behavior related to pedal operation has been used for evaluating the driver’s habits and the acceptability of various types of support devices. However, it has not been used for estimating driver workload related to pedal operation. To examine driver workload, this study divided pedal operation magnitude into two components: a learning/judgment component and a correcting component for prediction errors. A method was devised of separating these two components.
2016-04-05
Journal Article
2016-01-1402
Jeffrey Hurlbut, Daniel Cashen, Emily Robb, Lora L. Spangler, Jim Eckhart
Abstract Head-up display (HUD) technology creates inherent driver safety advantages by displaying critical information directly in the driver’s line of sight, reducing eyes off road and accommodation time. This is accomplished using a system of relay optics and windshield reflection to generate a virtual image that appears to hover over the hood near the bumper. The windshield is an integral optical component of the HUD system, but unfortunately the windshield-air interface causes a double image ghost effect as a result of refractive index change, reducing HUD image clarity. Current technology uses a constant angle wedged PVB windshield interlayer to eliminate double image at a single driver height. However, the HUD double image persists for all other viewing locations. Eastman Chemical Company has developed a new interlayer technology which eliminates the double image at all driver locations by tuning the wedge angle as a function of driver occupant seated height.
2016-04-05
Technical Paper
2016-01-1403
Jeff D. Colwell, Christopher D. Henry
Abstract Data from a full-scale vehicle burn test involving a cargo van illustrated how temperature distributions changed over time, the manner in which fire spread, and how patterns produced correlated to the origin of the fire. The fire was initiated on the driver’s side of the engine compartment and initially grew slowly with the high-temperature zone near the area of origin. Once the peak temperature reached about 540°C, the rate of flame spread increased such that over the next 4 minutes the fire spread across the entire engine compartment. In the next stage of the fire, which occurred shortly after full involvement of the engine compartment, the fire spread into the passenger compartment. A strong vertical temperature gradient developed from the ceiling to the floor and as the passenger compartment became fully involved, the passenger compartment temperatures both increased and became more uniform.
2016-04-05
Technical Paper
2016-01-0040
Ming Meng, Wilson Khoo
The modern vehicle development is highly dependent on software. The software development plays an extremely important role in vehicle safety and security. In order to ensure software high quality and safety standards, we have investigated the secure software development process and analyzed the works in this area. Based on our analysis, we have identified the similarities and differences between the secure software development process and the existing vehicle development process. We then made suggestions on how to adopt the secure software development process in the overall vehicle development process.
2016-04-05
Technical Paper
2016-01-0046
Markus Ernst, Mario Hirz, Jurgen Fabian
Abstract A steady increasing share and complexity of automotive software is a huge challenge for quality management during software development and in-use phases. In cases of faults occurring in customer’s use, warranty leads to product recalls which are typically associated with high costs. To avoid software faults efficiently, quality management and enhanced development processes have to be realized by the introduction of specific analysis methods and Key Process/Performance Indicators (KPIs) to enable objective quality evaluations as soon as possible during product development process. The paper introduces an application of specific analysis methods by using KPIs and discusses their potential for automotive software quality improvement. Target is to support quality evaluation and risk-analysis for the release process of automotive software.
2016-04-05
Technical Paper
2016-01-0056
Bjoern Steurich, Klaus Scheibert, Axel Freiwald, Martin Klimke
Abstract Vehicle manufacturers are challenged by rising costs for vehicle recalls. A major part of the costs are caused by software updates. This paper describes a feasibility study on how to implement software update over the air (SOTA) in light vehicles. The differences and special challenges in the automotive environment in comparison to the cellular industry will be explained. Three key requirements focus on the drivers’ acceptance and thus are crucial for the vehicle manufacturers: SOTA must be protected against malicious attacks. SOTA shall interfere as little as possible with the availability of a vehicle. Long update processes with long vehicle downtimes or even complete fails must be avoided. The functional safety of the vehicle during operation may not be limited in any way The study gives options how those objectives can be achieved.
2016-04-05
Technical Paper
2016-01-0068
Yoshihiro Ujiie, Takeshi Kishikawa, Tomoyuki Haga, Hideki Matsushima, Tohru Wakabayashi, Masato Tanabe, Yoshihiko Kitamura, Jun Anzai
Abstract Controller area network (CAN) technology is widely adopted in vehicles, but attention has been drawn recently to its lack of security mechanisms. Numerous countermeasures have been proposed, but none can be regarded as a generic solution, in part because all the proposed countermeasures require extensive modifications to existing in-vehicle systems. To arrive at a solution to this problem, we propose a new method of protecting CAN without the need to modify existing systems. In this paper, we explain the principle of our proposed method and the architecture of the electronic control unit (ECU) that implements it. We report the result of our experiments and show its efficacy against typical security threats faced by CAN.
2016-04-05
Technical Paper
2016-01-0066
Joe Hupcey, Bryan Ramirez
Abstract The number one priority in vehicle security is to harden the root-of-trust; from which everything else - the hardware, firmware, OS, and application layer’s security - is derived. If the root-of-trust can be compromised, then the whole system is vulnerable. In the near future the root-of-trust will effectively be an encryption key - a digital signature for each vehicle - that will be stored in a secure memory element inside all vehicles. In this paper we will show how a mathematical, formal analysis technique can be applied to ensure that this secure storage cannot (A) be read by an unauthorized party or accidentally “leak” to the outputs or (B) be altered, overwritten, or erased by unauthorized entities. We will include a real-world case study from a consumer electronics maker that has successfully used this technology to secure their products from attacks 24/7/365.
2016-04-05
Technical Paper
2016-01-0067
Ryan Wilson, Wayne Music, Brian Anderson
Modern vehicular systems rely on millions of lines of code that must occasionally be updated to add new functions or to patch flaws to ensure safe and secure operation. Updates accomplished through a compromised cellular base station could lead to an update process that may be vulnerable to attack. We have been investigating techniques for determining whether an LTE base station (known as an eNodeB) appears to be suspicious, so that an update could be paused or terminated until a trusted eNodeB is available. We describe a detector we developed as part of our research that scans LTE signals for anomalies and provides an alert when an anomaly is found.
2016-04-05
Technical Paper
2016-01-0063
Karsten Schmidt, Harald Zweck, Udo Dannebaum
Abstract/Short Version Introduction The introduction of Ethernet and Gigabit Ethernet [2] as the main invehicle network infrastructure is the technical foundation for different new functionalities such as piloted driving, minimizing the CO2- footprint and others. The high data rate of such systems influences also the used microcontrollers due the fact that a big amount of data has to be transferred, encrypted, etc.Figure 1 Motivation - Vehicles will become connected to uncontrolled networks The usage of Ethernet as the in-vehicle-network enables the possibility that future road vehicles are going to be connected with other vehicles and information systems to improve system functionality. These previously closed automotive systems will be opened up for external access (see Figure 1). This can be Car2X connectivity or connection to personal devices.
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