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Viewing 241 to 270 of 11101
2016-04-05
Technical Paper
2016-01-1286
Takuya Hara, Takahiro Shiga, Kazutaka Kimura, Akinori Sato
Abstract Introducing effective technologies to reduce carbon emissions in the transport sector is a critical issue for automotive manufacturers to contribute to sustainable development. Unlike the plug-in electric vehicles (PEVs), whose effectiveness is dependent on the carbon intensity of grid electricity, the solar hybrid vehicle (SHV) can be an alternative electric vehicle because of its off-grid, zero-emission electric technology. Its usability is also advantageous because it does not require manual charging by the users. This study aims at evaluating the economic, environmental, and usability benefits of SHV by comparing it with other types of vehicles including PEVs. By setting cost and energy efficiency on the basis of the assumed technology level in 2030, annual cost and annual CO2 emissions of each vehicle are calculated using the daily mileage pattern obtained from a user survey of 5,000 people in Japan and the daily radiation data for each corresponding user.
2016-04-05
Technical Paper
2016-01-1266
Shinichi Urabe, Kazutaka Kimura, Yuki Kudo, Akinori Sato
Abstract Solar and other green energy technologies are attracting attention as a means of helping to address global warming caused by CO2 and other emission gases. Countries, factories, and individual homes around the world have already introduced photovoltaic energy power sources, a trend that is likely to increase in the future. Electric vehicles powered from photovoltaic energy systems can help decrease the CO2 emmissions caused by vehicles. Unlike vehicles used for solar car racing, it is not easy to equip conventional vehicles with solar modules because the available area for module installation is very small to maintain cabin space, and the body lines of conventional vehicles are also usually slightly rounded. These factors decrease the performance of photovoltaic energy systems and prevent sufficient electric power generation. This research aimed to estimate the effectiveness of a solar module power generating system equipped on a conventional car, the Toyota Prius PHV.
2016-04-05
Technical Paper
2016-01-1211
Hua Tian, WeiGuang Wang, Ge-Qun Shu, Xingyu Liang, Haiqiao Wei
Abstract Power lithium-ion battery is the core component of electric vehicles and hybrid electric vehicles (EVs and HEVs). Thermal management at different operating conditions affects the life, security and stability of lithium-ion battery pack. In this paper, a one-dimensional, multiscale, electrochemical-thermal coupled model was applied and perfected for a flat-plate-battery pack. The model is capable of predicting thermal and electrochemical behaviors of battery. To provide more guidance for the selection of thermal management, temperature evolutions and distributions in the battery pack at various ambient temperatures, discharge rates and thermal radiation coefficients were simulated based on six types of thermal management (adiabatic, natural convection, air cooling, liquid cooling, phase change material cooling, isothermal).
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
2016-01-1465
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
2016-01-1463
Jeffrey Aaron Suway, Judson Welcher
Abstract It is extremely important to accurately depict photographs or video taken of a scene at night, when attempting to show how the subject scene appeared. It is widely understood that digital image sensors cannot capture the large dynamic range that can be seen by the human eye. Furthermore, todays commercially available printers, computer monitors, TV’s or other displays cannot reproduce the dynamic range that is captured by the digital cameras. Therefore, care must be taken when presenting a photograph or video while attempting to accurately depict a subject scene. However, there are many parameters that can be altered, while taking a photograph or video, to make a subject scene either too bright or too dark. Similarly, adjustments can be made to a printer or display to make the image appear either too bright or too dark. There have been several published papers and studies dealing with how to properly capture and calibrate photographs and video of a subject scene at night.
2016-04-05
Technical Paper
2016-01-1464
Jorge Martins, Ricardo Ribeiro, Pedro Neves, F. P. Brito
Abstract The main source for the estimation of stiffness coefficients to be used in accident reconstruction calculations is a very large database of crash-test related information from NHTSA. However, that database includes only car models sold in the USA. Unfortunately, there is no such information for European-only cars besides the raw video recordings of EuroNCAP crash tests. In the present work a methodology is proposed to estimate the stiffness coefficients of European-only models from video images of EuroNCAP crash tests. However, these images are intricate to assess, because the car front is crushed into a deformable barrier at 40% of the front width and usually the bonnet (hood) hides most of the crash damage. Therefore, the top images could not be used straightforward, so a procedure was envisaged to circumvent this difficulty and still allow to calculate stiffness coefficients for European-only cars.
2016-04-05
Technical Paper
2016-01-1461
William T. Neale, David Danaher, Sean McDonough, Tomas Owens
Abstract There are numerous publically available smart phone applications designed to track the speed and position of the user. By accessing the phones built in GPS receivers, these applications record the position over time of the phone and report the record on the phone itself, and typically on the application’s website. These applications range in cost from free to a few dollars, with some, that advertise greater functionality, costing significantly higher. This paper examines the reliability of the data reported through these applications, and the potential for these applications to be useful in certain conditions where monitoring and recording vehicle or pedestrian movement is needed. To analyze the reliability of the applications, three of the more popular and widely used tracking programs were downloaded to three different smart phones to represent a good spectrum of operating platforms.
2016-04-05
Technical Paper
2016-01-1457
John M. Scanlon, Kerry Page, Rini Sherony, Hampton C. Gabler
Abstract There are over 4,500 fatal intersection crashes each year in the United States. Intersection Advanced Driver Assistance Systems (I-ADAS) are emerging active safety systems designed to detect an imminent intersection crash and either provide a warning or perform an automated evasive maneuver. The performance of an I-ADAS will depend on the ability of the onboard sensors to detect an imminent collision early enough for an I-ADAS to respond in a timely manner. One promising method for determining the earliest detection opportunity is through the reconstruction of real-world intersection crashes. After determining the earliest detection opportunity, the required sensor range, orientation, and field of view can then be determined through the simulation of these crashes as if the vehicles had been equipped with an I-ADAS.
2016-04-05
Technical Paper
2016-01-1458
Ryuta Ono, Wataru Ike, Yuki Fukaya
Abstract Toyota Safety Sense is a safety system package developed to help drivers avoid accident types with a high frequency of occurrence. This paper deals with pre-collision system which forms the core of Toyota Safety Sense, especially Toyota Safety Sense P which uses a combined sensor configuration consisting of a monocular camera paired with millimeter wave radar, in order to achieve both high recognition performance and reliability. The use of a wide-angle monocular camera, millimeter wave radar integrated in the front grill emblem, and a collision determination algorithm for pedestrian targets enabled the development of a pre-collision system comprising detection capability of crossing pedestrians. Toyota has developed warning and pre-collision brake assist for driver to assist in avoiding a collision effectively; In addition, Pre-collision brake has achieved high level of performance for the drivers who cannot avoid a collision.
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
2016-01-1472
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
2016-01-1471
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
2016-01-1470
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
2016-01-1469
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
2016-01-1467
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
2016-01-1482
Paul Montalbano, Daniel Melcher, Rachel Keller, Thomas Rush, Jay Przybyla
Abstract A number of methods have been presented previously in the literature for determination of the impact speed of a motorcycle or scooter at its point of contact with another, typically larger and heavier, vehicle or object. However, all introduced methods to date have known limitations, especially as there are often significant challenges in gathering the needed data after a collision. Unlike passenger vehicles and commercial vehicles, most motorcycles and scooters carry no onboard electronic data recorders to provide insight into the impact phase of the collision. Recent research into automobile speedometers has shown that certain types of modern stepper motor based speedometers and tachometers can provide useful data for a collision reconstruction analysis if the instrument cluster loses electrical power during the impact, resulting in a “frozen” needle indication.
2016-04-05
Technical Paper
2016-01-1483
Ross Hunter, Ryan Fix, Felix Lee, David King
Abstract The objective of this study was to assess the accuracy of using high-speed frontal barrier crash tests to predict the impact speed, i.e. equivalent barrier speed (EBS), of a lower-speed frontal barrier crash. Force-displacement (F-D) curves were produced by synchronizing the load cell barrier (LCB) data with the accelerometer data. Our analysis revealed that the F-D curves, including the rebound phase, for the same vehicle model at the same impact speed were generally similar. The test vehicle crush at the time of barrier separation, determined from the F-D curves, was on average 17±16% (N = 150) greater than the reported maximum hand-measured residual crush to the bumper cover. The EBS calculated from the F-D curves was on average 4±4% (N=158) greater than the reported EBS, indicating that using F-D curves derived from LCB data is a reliable method for calculating vehicle approach energy in a crash test.
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
2016-01-1480
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
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
2016-01-1478
William T. Neale, David Hessel, Daniel Koch
Abstract This paper presents a methodology for determining the position and speed of objects such as vehicles, pedestrians, or cyclists that are visible in video footage captured with only one camera. Objects are tracked in the video footage based on the change in pixels that represent the object moving. Commercially available programs such as PFTracktm and Adobe After Effectstm contain automated pixel tracking features that record the position of the pixel, over time, two dimensionally using the video’s resolution as a Cartesian coordinate system. The coordinate data of the pixel over time can then be transformed to three dimensional data by ray tracing the pixel coordinates onto three dimensional geometry of the same scene that is visible in the video footage background.
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
2016-01-1475
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
Technical Paper
2016-01-1491
Eunjoo Hwang, Jason Hallman, Katelyn Klein, Jonathan Rupp, Matthew Reed, Jingwen Hu
Abstract Current finite element (FE) human body models (HBMs) generally only represent young and mid-size male occupants and do not account for body shape and composition variations among the population. Because it generally takes several years to build a whole-body HBM, a method to rapidly develop HBMs with a wide range of human attributes (size, age, obesity level, etc.) is critically needed. Therefore, the objective of this study was to evaluate the feasibility of using a mesh morphing method to rapidly generate skeleton and whole-body HBMs based on statistical geometry targets developed previously. THUMS V4.01 mid-size male model jointly developed by Toyota Motor Corporation and Toyota Central R&D Labs was used in this study as the baseline HBM to be morphed. Radial basis function (RBF) was used to morph the baseline model into the target geometries.
2016-04-05
Technical Paper
2016-01-1490
Hans W. Hauschild, Frank Pintar, Dale Halloway, Mark Meyer, Rodney Rudd
Abstract Oblique crashes to the vehicle front corner may not be characteristic of either frontal or side impacts. This research evaluated occupant response in oblique crashes for a driver, rear adult passenger, and a rear child passenger. Occupant responses and injury potential were evaluated for seating positions as either a far-or near-side occupant. Two crash tests were conducted with a subcompact car. The vehicle’s longitudinal axis was oriented 45 degrees to the direction of travel on a moving platform and pulled into a wall at 56 km/h. Dummies utilized for the seating positions were an adult dummy (50th-percentile-HIII and THOR-Alpha) for the front-left (driver) position, 5th-percentile-female-HIII for the right-rear position, and a 3-year-old HIII for the left-rear position.
2016-04-05
Technical Paper
2016-01-1489
Logan Miller, James Gaewsky, Ashley Weaver, Joel Stitzel, Nicholas White
Abstract Crash reconstructions using finite element (FE) vehicle and human body models (HBMs) allow researchers to investigate injury mechanisms, predict injury risk, and evaluate the effectiveness of injury mitigation systems, ultimately leading to a reduced risk of fatal and severe injury in motor vehicle crashes (MVCs). To predict injuries, regional-level injury metrics were implemented into the Total Human Model for Safety (THUMS) full body HBM. THUMS was virtually instrumented with cross-sectional planes to measure forces and moments in the femurs, upper and lower tibias, ankles, pelvis (pubic symphysis, ilium, ischium, sacrum, ischial tuberosity, and inferior and superior pubic ramus), and the cervical, thoracic, and lumbar vertebrae and intervertebral discs. To measure accelerations, virtual accelerometers were implemented in the head, thoracic vertebrae, sternum, ribs, and pelvis.
2016-04-05
Journal Article
2016-01-1488
Derek Jones, James Gaewsky, Ashley Weaver, Joel Stitzel
Abstract Computational finite element (FE) modeling of real world motor vehicle crashes (MVCs) is valuable for analyzing crash-induced injury patterns and mechanisms. Due to unavailability of detailed modern FE vehicle models, a simplified vehicle model (SVM) based on laser scans of fourteen modern vehicle interiors was used. A crash reconstruction algorithm was developed to semi-automatically tune the properties of the SVM to a particular vehicle make and model, and subsequently reconstruct a real world MVC using the tuned SVM. The required algorithm inputs are anthropomorphic test device position data, deceleration crash pulses from a specific New Car Assessment Program (NCAP) crash test, and vehicle interior property ranges. A series of automated geometric transformations and five LSDyna positioning simulations were performed to match the FE Hybrid III’s (HIII) position within the SVM to reported data. Once positioned, a baseline simulation using the crash test pulse was created.
2016-04-05
Technical Paper
2016-01-1487
Zhenhai Gao, Chuzhao Li, Hongyu Hu, Chaoyang Chen, Hui Zhao, Helen Yu
Abstract At the collision moment, a driver’s lower extremity will be in different foot position, which leads to the different posture of the lower extremity with various muscle activations. These will affect the driver’s injury during collision, so it is necessary to investigate further. A simulated collision scene was constructed, and 20 participants (10 male and 10 female) were recruited for the test in a driving simulator. The braking posture and muscle activation of eight major muscles of driver’s lower extremity (both legs) were measured. The muscle activations in different postures were then analyzed. At the collision moment, the right leg was possible to be on the brake (male, 40%; female, 45%), in the air (male, 27.5%; female, 37.5%) or even on the accelerator (male, 25%; female, 12.5%). The left leg was on the floor all along.
Viewing 241 to 270 of 11101