Display:

Results

Viewing 241 to 270 of 22745
2016-04-05
Technical Paper
2016-01-0161
Valentin Soloiu, Imani Augusma, Deon Lucien, Mary Thomas, Roccio Alba-Flores
Abstract This study presents the design and development of a vehicle platform with intelligent sensors that has the capabilities to drive independently and cooperatively on roads. An integrated active safety system has been designed to optimize the human senses using ultrasonic infrared sensors and transmitter/receiver modules, to increase the human vision, feel and communication for increased road safety, lower congestion rates, and decrease CO2 emissions. Ultrasonic sensors mounted on the platform, emitted longitudinal 40 kHz waves and received echoes of these sound waves when an object was within its direction. The duration was converted to a distance measurement to detect obstacles as well as using distance measurement threshold values to implement adaptive cruise control. Infrared sensors equipped with an IR LED and a bipolar transistor detected a change in light intensity to identify road lanes.
2016-04-05
Technical Paper
2016-01-0163
Thomas Rothermel, Jürgen Pitz, Hans-Christian Reuss
Abstract This paper proposes a framework for semi-autonomous longitudinal guidance for electric vehicles. To lower the risk for pedestrian collisions in urban areas, a velocity trajectory which is given by the driver is optimized with respect to safety aspects with the help of Nonlinear Model Predictive Control (NMPC). Safety aspects, such as speed limits and pedestrians on the roadway, are considered as velocity and spatial constraints within prediction horizon in NMPC formulation. A slack variable is introduced to enable overshooting of velocity constraints in situations with low risk potential to rise driver acceptance. By changing the weight of slack variable, the control authority can be shifted continuously from driver to automation. Within this work, a prototypical real-time implementation of the longitudinal guidance system is presented and the potential of the approach is demonstrated in human-in-the-loop test drives in the Stuttgart Driving Simulator.
2016-04-05
Technical Paper
2016-01-0158
Toshio Ito, Arata Takata, Kenta Oosawa
Abstract Automation of vehicles can be expected to improve safety, comfort and efficiency, and is being developed in various countries. Introduction of automated driving can be ranked from 0 to 5 (0: no automation, 1: driver assistance, 2: partial automation, 3: conditional automation, 4: high automation, 5: full automation). Currently, feasible automation levels are considered to be levels 2 or 3, and human manual take-over from the automated system is needed when the automated system exceeds these levels. In this situation, time required for take-over is an important issue. This study focuses on describing driving simulator experimental results of time required for take-over. The experimental scenario is that the automated system finds an object ahead during automated driving on the highway, and issues a take-over request to the driver. The subject driver can be in the following driver situations: hands-on or hands-off the steering, and strong or weak distractions.
2016-04-05
Journal Article
2016-01-0159
Luting Wang, Chong Cao, Bo Chen
Abstract This paper studies the bi-directional power flow control between Plug-in Electric Vehicles (PEVs) and an electrical grid. A grid-tied charging system that enables both Grid-to-Vehicle (G2V) and Vehicle-to-Grid (V2G) charging/discharging is modeled using SimPowerSystems in Matlab/Simulink environment. A bi-directional AC-DC converter and a bi-directional DC-DC buck-boost converter are integrated to charge and discharge PEV batteries. For AC-DC converter control, Predictive Current Control (PCC) strategy is employed to enable grid current to reach a reference current after one modulation period. In addition, Phase Lock Loop (PLL) and a band-stop filter are designed to lock the grid voltage phase and reduce harmonics. Bi-directional power flow is realized by controlling the mode of the DC-DC converter. Simulation tests are conducted to evaluate the performance of this bi-directional charging system.
2016-04-05
Journal Article
2016-01-0160
Takayuki Shimizu, Tomoya Ono, Wataru Hirohashi, Kunihiko Kumita, Yasuhiro Hayashi
Abstract In this paper, we consider smart charging and vehicle-to-home (V2H) technologies for plugin electric vehicles coordinated with home energy management systems (HEMS) for automated demand response. In this system, plugin electric vehicles automatically react to demand response events with or without HEMS’s coordination, while vehicles are charged and discharged (i.e., V2H) in appropriate time slots by taking into account demand response events, time-ofuse rate information, and users’ vehicle usage plan. We introduce three approaches on home energy management: centralized energy control, distributed energy control, and coordinated energy control. We implemented smart charging and V2H systems by employing two sets of standardized communication protocols: one using OpenADR 2.0b, SEP 2.0, and SAE standards and the other using OpenADR 2.0b, ECHONET Lite, and ISO/IEC 15118.
2016-04-05
Technical Paper
2016-01-0154
Pritesh Jain, Purushottam Bhumre, Saakshi Jain
Abstract This paper describes the Common Automobile Program (CAP) that can be implemented to improve mass transportation. CAP is the use of automated electric vehicles using smart navigation and control technologies to improve mass transportation. In CAP, common vehicles are used by different passengers, thus, reducing the on-road traffic and also the parking space required. Various low-cost stations are to be built along specified paths and the vehicle can be used at the convenience of the commuter. Currently, buses and trains require the passengers to wait at the station and a significant amount of time is spent at intermediate stops. The vehicle in CAP runs directly from origin to destination and also eliminates the waiting time at stations. Passengers do not wait for vehicles; instead vehicles wait for the passengers. The journey starts as the passenger enters the station and selects the destination.
2016-04-05
Journal Article
2016-01-0155
Ondrej Santin, Jaroslav Pekar, Jaroslav Beran, Anthony D'Amato, Engin Ozatay, John Michelini, Steven Szwabowski, Dimitar Filev
Abstract Automotive cruise control systems are used to automatically maintain the speed of a vehicle at a desired speed set-point. It has been shown that fuel economy while in cruise control can be improved using advanced control methods. The objective of this paper is to validate an Adaptive Nonlinear Model Predictive Controller (ANLMPC) implemented in a vehicle equiped with standard production Powertrain Control Module (PCM). Application and analysis of Model Predictive Control utilizing road grade preview information has been reported by many authors, namely for commercial vehicles. The authors reported simulations and application of linear and nonlinear MPC based on models with fixed parameters, which may lead to inaccurate results in the real world driving conditions. The significant noise factors are namely vehicle mass, actual weather conditions, fuel type, etc.
2016-04-05
Technical Paper
2016-01-0201
Armin Traussnig, Wilko Jansen, Heinz Petutschnig, Sepp Steiner, Petra Gruen
Abstract In order to meet current and future emission and CO2 targets, an efficient vehicle thermal management system is one of the key factors in conventional as well as in electrified powertrains. Global vehicle simulation is already a well-established tool to support the vehicle development process. In contrast to conventional vehicles, electrified powertrains offer an additional challenge to the thermal conditioning: the durability of E-components is not only influenced by temperature peaks but also by the duration and amplitude of temperature swings as well as temperature gradients within the components during their lifetime. Keeping all components always at the preferred lowest temperature level to avoid ageing under any conditions (driving, parking, etc.) will result in very high energy consumption which is in contradiction to the efficiency targets.
2016-04-05
Technical Paper
2016-01-0197
Ravi Ranjan, Kaushal Kumar Jha, Lakshmaiah Brahmasani, Parvej Khan
Abstract The traditional approach of engine thermal behavior of engine during startup has largely been dependent on experimental studies and high fidelity simulations like CFD. However, these techniques require considerable effort, cost and time. The low fidelity simulations validated with experimental results are becoming more popular due to their ease in handling the several parameters such as cost effectiveness and quick predictive results. A four point mass model of engine thermal behavior during cold start has been developed to study the engine warm up temperature behavior. The four point mass model considers the lumped mass of coolant, mass of engine directly associated with the coolant, mass of engine oil and mass of engine directly associated with the engine oil. The advantage of four point model is to predict the coolant temperature as well as lubricant temperature during the transient warm up cycle of the engine.
2016-04-05
Journal Article
2016-01-0543
Takashi Hara, Masaki Kato, Kazuki Mizutani
Abstract There are such outside door handles called smart handles which have a transmitting antenna, a lock/unlock sensor, and a sensor detection circuit, with which operation of door lock is possible just by "touching" the electrostatic-capacitance type sensor of the handles.As the design of the outside handles, body color painting and Cr plating are adopted. However, if plating is applied over the entire surface of a smart handle, electromagnetic waves transmitted from the antenna will be blocked since plating material is electrically conductive. In addition to this, touching a part other than the sensor may change the electrostatic-capacitance of the sensor, which results in unwanted functioning of the lock/unlock sensor. Because of this, only part of the handle, which does not hinder the transmission of electromagnetic waves and does not cause unwanted functioning, is covered by plating, that is called, "Partially plated specifications" (Figure 1).
2016-04-05
Technical Paper
2016-01-0561
Seungha Lee, Youngbok Lee, Kyoungchan Han, Kyoung Min Lee, Jun Yu, Junyong Lee, Kyoungdoug Min
Abstract Currently, diesel engine-out exhaust NOx emission level prediction is a major challenge for complying with the stricter emission legislation and for control purpose of the after-treatment system. Most of the NOx prediction research is based on the Zeldovich thermal mechanism, which is reasonable from the physical point of view and for its simplicity. Nevertheless, there are some predictable range limitations, such as low temperature with high EGR rate operating conditions or high temperature with low EGR rates. In the present paper, 3 additional considerations, pilot burned gas mixing before the main injection; major NO formation area; concentration correction, were applied to the previously developed real-time NO estimation model based on in-cylinder pressure and data available from ECU. The model improvement was verified on a 1.6 liter EURO5 diesel engine in both steady and transient operation.
2016-04-05
Technical Paper
2016-01-0500
Akira Kato, Masayuki Takano, Kohei Hase, Satoko Inuzuka, Toshiyuki Dobashi, Tsuyoshi Sugimoto, Nobuaki Takazawa
Abstract In this report, adhesion mechanism between epoxy resin and primer and between primer and Ni platting in Hybrid vehicle (HV) was investigated. Adhesion forces are thought to be a combination of mechanical bond forces (such as anchor effect), chemical bond forces and physical bond forces (such as hydrogen bonding and Van der Waals force). Currently there is insufficient understanding of the adhesion mechanism. In particular, the extent to which the three bond forces contribute to adhesion strength. So the adhesion mechanism of polyimide primers was analyzed using a number of different methods, including transmission electron microscope (TEM) and atomic force microscope (AFM) observation, to determine the contributions of the three bonding forces. Molecular simulation was also used to investigate the relationship between adhesion strength and the molecular structure of the primer.
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
2016-01-1461
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
Journal Article
2016-01-1462
Louis R. Peck, Mu-Hua Cheng
Abstract Three targeted vehicles of varying size were measured using an optimized, practical photogrammetry technique and the results were compared to measurements acquired via total station. The photogrammetry method included the use of a field-calibrated DSLR camera equipped with a fixed 20 mm lens, retroreflective targets sized for vehicular modeling, and a CNC-machined scale bar. Eight photographs were taken from proper angles and processed using a commercially available photogrammetry package. This data was merged with the total station data using a cloud-to-cloud registration process for point-to-point comparison of positional data. The average residual between corresponding photogrammetry and total station points was 1.7 mm (N = 258, SD = 0.8 mm) with a 95% confidence limit of 3.1 mm. Considering this low residual, one of the sample vehicles was re-measured using a high accuracy FaroArm for comparison to the photogrammetry technique.
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
Journal Article
2016-01-1456
Rini Sherony, Renran Tian, Stanley Chien, Li Fu, Yaobin Chen, Hiroyuki Takahashi
Abstract Many vehicles are currently equipped with active safety systems that can detect vulnerable road users like pedestrians and bicyclists, to mitigate associated conflicts with vehicles. With the advancements in technologies and algorithms, detailed motions of these targets, especially the limb motions, are being considered for improving the efficiency and reliability of object detection. Thus, it becomes important to understand these limb motions to support the design and evaluation of many vehicular safety systems. However in current literature, there is no agreement being reached on whether or not and how often these limbs move, especially at the most critical moments for potential crashes. In this study, a total of 832 pedestrian walking or cyclist biking cases were randomly selected from one large-scale naturalistic driving database containing 480,000 video segments with a total size of 94TB, and then the 832 video clips were analyzed focusing on their limb motions.
2016-04-05
Technical Paper
2016-01-1453
I-Hsuan Lee, Bi-Cheng Luan
Abstract Autonomous emergency braking (AEB) systems is one of the functions of the Advanced Driver Assists System to avoid or mitigate vehicle frontal collisions. Most of the previous studies focus on two-car scenario where the host vehicle monitors the distances to the vehicles in front, and automatically applies emergency brake when a collision is imminent. The purpose of this paper is to develop an Advanced-AEB control system that mitigates collisions in a multi-car scenario by measuring the distances to the vehicles in front as well as those to the vehicles behind using the concept of impedance control. A simple gain-scheduling PI controller was designed for the host vehicle to track the reference inputs generated by the impedance control. The preliminary simulation results demonstrate that the proposed AEB is effective in mitigating the collisions in a 3-car following scenario.
2016-04-05
Technical Paper
2016-01-1454
Libo Dong, Stanley Chien, Jiang-Yu Zheng, Yaobin Chen, Rini Sherony, Hiroyuki Takahashi
Abstract Pedestrian Automatic Emergency Braking (PAEB) for helping avoiding/mitigating pedestrian crashes has been equipped on some passenger vehicles. Since approximately 70% pedestrian crashes occur in dark conditions, one of the important components in the PAEB evaluation is the development of standard testing at night. The test facility should include representative low-illuminance environment to enable the examination of the sensing and control functions of different PAEB systems. The goal of this research is to characterize and model light source distributions and variations in the low-illuminance environment and determine possible ways to reconstruct such an environment for PAEB evaluation. This paper describes a general method to collect light sources and illuminance information by processing large amount of potential collision locations at night from naturalistic driving video data.
2016-04-05
Technical Paper
2016-01-1450
Peter Vertal, Hermann Steffan
Abstract The objective of this work is to test the potential benefit of active pedestrian protection systems. The tests are based on real fatal accidents with passenger cars that were not equipped with active safety systems. Tests have been conducted in order to evaluate what the real benefit of the active safety system would be, and not to gain only a methodological prediction. The testing procedure was the first independent testing in the world which was based on real fatal pedestrian accidents. The aim of the tests is to evaluate the effectiveness of the Volvo pedestrian detection system. The in-depth accident database ZEDATU contains about 300 fatal pedestrian traffic accidents in urban areas. Eighteen cases of pedestrians hit by the front end of a passenger vehicle were extracted from this database. Cases covering an average traffic scenario have been reconstructed to obtain detailed model situations for testing.
2016-04-05
Technical Paper
2016-01-1447
Qiang Yi, Stanley Chien, Jason Brink, Wensen Niu, Lingxi Li, Yaobin Chen, Chi-Chen Chen, Rini Sherony, Hiroyuki Takahashi
Abstract As part of active safety systems for reducing bicyclist fatalities and injuries, Bicyclist Pre-Collision System (BPCS), also known as Bicyclist Autonomous Emergency Braking System, is being studied currently by several vehicles manufactures. This paper describes the development of a surrogate bicyclist which includes a surrogate bicycle and a surrogate bicycle rider to support the development and evaluation of BPCS. The surrogate bicycle is designed to represent the visual and radar characteristics of real bicyclists in the United States. The size of bicycle surrogate mimics the 26 inch adult bicycle, which is the most popular adult bicycle sold in the US. The radar cross section (RCS) of the surrogate bicycle is designed based on RCS measurement of the real adult sized bicycles.
2016-04-05
Technical Paper
2016-01-1445
Jonathan Dobres, Bryan Reimer, Bruce Mehler, James Foley, Kazutoshi Ebe, Bobbie Seppelt, Linda Angell
Abstract Driving behaviors change over the lifespan, and some of these changes influence how a driver allocates visual attention. The present study examined the allocation of glances during single-task (just driving) and dual-task highway driving (concurrently tuning the radio using either visual-manual or auditory-vocal controls). Results indicate that older drivers maintained significantly longer single glance durations across tasks compared to younger drivers. Compared to just driving, visual-manual radio tuning was associated with longer single glance durations for both age groups. Off-road glances were subcategorized as glances to the instrument cluster and mirrors (“situationally-relevant”), “center stack”, and “other”. During baseline driving, older drivers spent more time glancing to situationally-relevant targets. During both radio tuning task periods, in both age groups, the majority of glances were made to the center stack (the radio display).
2016-04-05
Technical Paper
2016-01-1446
Rini Sherony, Qiang Yi, Stanley Chien, Jason Brink, Mohammad Almutairi, Keyu Ruan, Wensen Niu, Lingxi Li, Yaobin Chen, Hiroyuki Takahashi
Abstract According to the U.S. National Highway Traffic Safety Administration, 743 pedal cyclists were killed and 48,000 were injured in motor vehicle crashes in 2013. As a novel active safety equipment to mitigate bicyclist crashes, bicyclist Pre-Collision Systems (PCSs) are being developed by many vehicle manufacturers. Therefore, developing equipment for evaluating bicyclist PCS is essential. This paper describes the development of a bicycle carrier for carrying the surrogate bicyclist in bicyclist PCS testing. An analysis on the United States national crash databases and videos from TASI 110 car naturalistic driving database was conducted to determine a set of most common crash scenarios, the motion speed and profile of bicycles. The bicycle carrier was designed to carry or pull the surrogate bicyclist for bicycle PCS evaluation. The carrier is a platform with a 4 wheel differential driving system.
2016-04-05
Technical Paper
2016-01-1443
Nazan Aksan, Lauren Sager, Sarah Hacker, Benjamin Lester, Jeffrey Dawson, Matthew Rizzo
Abstract We examined relative effectiveness of heads-up visual displays for lane departure warning (LDW) 39 younger to middle aged drivers (25-50, mean = 35 years) and 37 older drivers (66-87, mean = 77 years). The LDW included yellow “advisory” visuals in the center screen when the driver started drifting toward the adjacent lane. The visuals turned into red “imminent” when the tires overlapped with the lane markers. The LDW was turned off if the driver activated the turn signal. The visuals could be easily segregated from the background scene, making them salient but not disruptive to the driver’s forward field of view. The visuals were placed adjacent to the left and right lane markers in the lower half of the center screen.
2016-04-05
Technical Paper
2016-01-1442
David Miller, Mishel Johns, Hillary Page Ive, Nikhil Gowda, David Sirkin, Srinath Sibi, Brian Mok, Sudipto Aich, Wendy Ju
Abstract Age and experience influence driver ability to cope with transitions between automated and manual driving, especially when drivers are engaged in media use. This study evaluated three age cohorts (young/new drivers, adults, and seniors) on their performance in transitions from automated driving to manual vehicle control in a laboratory driving simulator. Drivers were given three tasks to perform during the automated driving segments: to watch a movie on a tablet, to read a story on a tablet, or to supervise the car's driving. We did not find significant differences in people's driving performance following the different tasks. We also did not find significant differences in driving performance between the people in each age group who successfully completed the study; however, the rejection rate of the senior age group was over 30% because many of the people in this age group had difficulty hearing instructions, understanding tasks, or remembering what to do.
2016-04-05
Technical Paper
2016-01-1440
Julia Seeanner, Johnell Brooks, Mary Mossey, Casey Jenkins, Paul Venhovens, Constance Truesdail
Abstract While motorcycle safety frequently focuses on topics like helmet use and engineering aspects such as anti-lock braking systems, little research has investigated aging riders’ use of technologies (i.e., phones, navigation systems, etc.) or the characteristics of older riders (defined as above the age of 40) who use them. This study surveyed a convenience sample of typical motorcycle riders in the United States in order to provide an overview of the types of technologies that riders of different age groups use while riding, problems or concerns about those technologies, as well as rider demographics and riding habits. The sample included 97 riders (84 males and 13 females) between the ages of 20 and 71 years (M= 50.9, SD= 10.6) who were divided into three age groups (under 40 years, between 40 and 50 years, 50 years and older).
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
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
2016-01-1472
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
2016-01-1467
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.
Viewing 241 to 270 of 22745

Filter