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Recent models of General Motors (GM) and selected Ford vehicles may be equipped with an event data recorder (EDR) that records information in the airbag sensing and diagnostic module (GM-SDM) or restraint control module (Ford-RCM). These systems have become a resource to the accident reconstructionist in the analysis of collisions involving data recorder equipped vehicles, as typically the data can be downloaded via the Vetronix Crash Data Retrieval (CDR) System. The purpose of this paper is to investigate the use of the CDR System in pedestrian accidents. A series of impacts using a pedestrian dummy and SDM equipped vehicles were performed. After each test, the SDM was downloaded via the CDR system and the data evaluated. The dummy and vehicle kinematics were documented and the vehicle impact response was compared with the SDM recorded velocity change and impact speed.

A series of low-speed straightline braking tests with two test drivers were conducted on a performance-based brake tester as an exploratory study to examine the effect of tire rolling radius on a light-duty truck. Data collected by the flat plate brake tester and a load cell to measure pedal force were used to evaluate differences in the braking characteristics and rollover propensity of a 1992 four-wheel drive pickup. Tests were conducted with the test vehicle in the stock configuration with standard size tires and after it was equipped with aftermarket body and suspension lift kits and three incrementally larger size sets of radial tires. An analysis of test data indicated that the additional ride height and oversize tires had a profound effect on pedal force gain and significantly increased the rollover propensity of the altered vehicle.

Collision data stored in the airbag sensing and diagnostic module (SDM) of 1996 and newer GM vehicles have become available to accident investigators through the Vetronix Crash Data Retrieval system. In this study, two experiments were performed to investigate the accuracy and sensitivity of the speed change reported by the SDM in low-speed crashes. First, two SDM-equipped vehicles were subjected to 260 staged frontal collisions with speed changes below 11 km/h. Second, the SDMs were removed from the vehicles and exposed to a wide variety of collision pulses on a linear motion sled. In all of the vehicle tests, the speed change reported by the SDM underestimated the actual speed change of the vehicle. Sled testing revealed that the shape, duration and peak acceleration of the collision pulse affected the accuracy of the SDM-reported speed change. Data from the sled tests were then used to evaluate how the SDM-reported speed change was calculated.

The in-cylinder bulk flow and turbulence characteristics in a spark ignition engine were examined using two particle image velocimetry (PIV) systems. The effects of a turbulence-generating valve (TGV) bulk flow and turbulence characteristics were investigated. The results show that both the motion and location of turbulent flow can be controlled by a TGV valve. This could be used to reduce the level of unburned hydrocarbons produced during a cold start. The time history and scales of turbulence [1, 2 and 3] were compared with those obtained using laser Doppler velocimetry. The developed PIV systems were accurate, and the measured data were reliable enough to permit discussion of the cycle-resolve and cycle-to-cycle variation of in-cylinder flow. At top dead center, the measured turbulence scales of motion in the flow with the TGV closed were two thirds of those obtained with the TGV open.

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.

Vehicle post-impact travel distances are often available to the accident reconstructionist. Energy dissipated after impact can be significant, and it is often necessary to account for this energy. The deceleration and energy dissipation experienced by a vehicle after a collision is dependent on many variables including tire rolling resistance, engine and drive-train resistance and aerodynamic drag. New technologies that significantly modify the traditional drive train, low rolling resistance tires, and new aerodynamic body designs affect vehicle deceleration, but associated data is not widely available. Roll-out tests were performed in which speed, acceleration and position measurements were made. Vehicles tested were equipped with hybrid (gasoline-electric) and standard engines, CVT (continuously variable transmission), manual and automatic transmissions, and two wheel and four-wheel drive.

Crash information, e.g. driving and impact speed, have to be determined from traces on the scene, as well as from examination of deformation patterns in order to assess the impact condition and the movement trajectories of the impacted body of bicyclists and pedestrians after car collision. Experts use the following information to calculate speed: Information on final position of vehicles, deformation pattern on vehicles, traces found on the road, such as braking and sliding marks, throw distances of pedestrians and cyclists and injury pattern, all these issues are given possibilities for reconstruction of the movement of the human body. While in car to car crashes the speed calculation is based on the momentum analysis and on energy balance hypothesis of classical physics, the calculation for pedestrian and bicycle accidents have to be based on traces only. The paper describes the possibilities of the use of throw distance as a reconstruction method.

Low-speed sideswipe collisions between tractor-semitrailers and passenger vehicles may result in large areas of visible damage to the passenger vehicle. However, due to the extended contact that occurs during these impacts, it is typical in these incidents for the crash pulse duration to be long and the vehicle accelerations to be correspondingly low. Research regarding the impact environment and resulting injury potential of the occupants during these types of impacts is limited. Five full-scale crash tests utilizing a tractor-semitrailer and a passenger car were conducted to explore the occupant responses during these types of collisions. The test vehicles included a van semitrailer pulled by a tractor and three identical mid-sized sedans. The occupants of the sedans included an instrumented Hybrid III 5th -percentile-male anthropomorphic test device (ATD) in the driver's seat and an un-instrumented Hybrid III 5th -percentile-female ATD in the left rear seat.

Instrumented human subject and anthropomorphic test device (ATD) responses to low speed lateral impacts were investigated. A series of 12 lateral collisions at various impact angles were conducted, 6 near-side and 6 far-side, with each test using an ATD and one human subject. Two restrained female subjects were utilized, with one positioned in the driver seat and one in the left rear seat. Each subject was exposed to 3 near-side and 3 far-side impacts. The restrained ATD was utilized in both the driver and left rear seats, undergoing 3 near-side and 3 far-side impacts in each position. The vehicle center of gravity (CG) change in velocity (delta-V) ranged from 5.5 to 9.4 km/h (3.4 to 5.8 mph). Video analysis was used for quantification and comparison of the human and ATD motions and interactions with interior vehicle structures. Human head, thorax, and low back accelerations were analyzed. Peak human subject head resultant accelerations ranged from 0.9 to 36.8 g’s.

Volunteer subject studies in low-speed rear impacts have shown that significant lumbar spine injuries are unlikely in such collisions. Anthropomorphic test devices (ATD) used in low to medium speed rear impact simulations have similarly revealed an unlikely mechanism to cause lumbar spine injuries. However, low back complaints after rear impacts are common in clinical practice. We attempt here to determine the incidence of lumbar spine injuries from actual field data which may provide an insight into the apparent paradox between experimental data and clinical practice. We examined the incidence of all spine injuries in the NASSCDS (National Automotive Sampling System - Crashworthiness Data System) database from 1993 to 2009. We limited the data to only look at rear-end crashes involving two vehicles.

Tire-pavement interaction noise (TPIN) is a dominant source for passenger cars and trucks above 40 km/h and 70 km/h, respectively. TPIN is mainly generated from the interaction between the tire and the pavement. In this paper, twenty-two passenger car radial (PCR) tires of the same size (16 in. radius) but with different tread patterns were tested on a non-porous asphalt pavement. For each tire, the noise data were collected using an on-board sound intensity (OBSI) system at five speeds in the range from 45 to 65 mph (from 72 to 105 km/h). The OBSI system used an optical sensor to record a once-per-revolution signal to monitor the vehicle speed. This signal was also used to perform order tracking analysis to break down the total tire noise into two components: tread pattern-related noise and non-tread pattern-related noise.

Collision reconstruction often involves calculations and computer simulations, which require an estimation of the weights of the involved vehicles. Although weight data is readily available for automobiles and light trucks, there is limited data for heavy vehicles, such as tractor-semitrailers, straight trucks, and the wide variety of trailers and combinations that may be encountered on North American roads. Although manufacturers always provide the gross vehicle weight ratings (GVWR) for these vehicles, tare weights are often more difficult to find, and in-service loading levels are often unknown. The resulting large uncertainty in the weight of a given truck can often affect reconstruction results. In Canada, the Ministry of Transportation of Ontario conducted a Commercial Vehicle Survey in 2012 that consisted of weight sampling over 45,000 heavy vehicles of various configurations.

For model year 2018, Freightliner introduced the New Cascadia model to their lineup of Class 8 trucks. Testing of the Freightliner New Cascadia with Detroit Diesel engines was conducted to evaluate the accuracy of the reported event data contained in the engine Electronic Control Units (ECUs) for these trucks. The testing showed that there are occurrences in DDEC Reports, specifically in the Last Stop Record and Hard Braking event data, when the time between successive event data points was two seconds rather than the reported one second interval. The occurrence of the two-second anomaly was not always present in a Last Stop Record or Hard Braking event. When the two-second anomaly was present in the event data, it occurred randomly and no pattern to when this anomaly occurs was determined. No method was found to be able to detect the presence of this anomaly from the review of a Last Stop Record or Hard Braking event.

Airbag deployment thresholds can be a useful metric of collision severity in accident reconstruction applications. The National Automotive Sampling System (NASS) has provided a publicly-available database of real-world motor vehicle collisions, including more than 10,000 event data recorder (EDR) reports retrieved from airbag control modules. These reports typically indicate the airbag deployment status and the corresponding Delta-V of each recorded event. A prior study analyzing crash data in the NASS database demonstrated the airbag deployment threshold varies between vehicle manufacturers and over time. However, the analysis was limited to Ford and GM vehicles due to insufficient data. This paper expands on the prior study of frontal airbag deployment thresholds by analyzing newer years of NASS EDR data (4,000 additional reports). We found that the Delta-V threshold for a 50% probability of deployment event is higher for Toyota than for GM and Ford vehicles.

Electric vehicles (EVs) and the development around them has been rapid in recent years. As the battery is the most essential component of an electric vehicle, a lot of research and analysis has been focused on ensuring safe and reliable performance of batteries. Considering the location, size, and operating conditions for EV batteries, they must be designed with an in-built safety infrastructure keeping in mind certain realistic scenarios such as fire exposure, mechanical vibration, collisions, over-charging, single cell failures, and others. In this paper, we discuss an overview of various EV battery failure mechanisms, present current safety and abuse testing methods and standards associated with such mechanisms and discuss the need for the development and implementation of additional testing standards to better characterize the safety performance of EV battery packs.

To satisfy the stringent regulations for exhaust gas emissions from gasoline-powered vehicles, large amounts of Rh and Pd have often been employed in three-way catalysts (TWCs) as the main active components. On the other hand, Pt-based TWCs are not often used in gasoline vehicles because Pt is readily sintered by its exhaust gases at approximately 1000 °C [1, 2]. In general, Pt-based TWCs must be located away from large thermal loads to maintain the active sites for gas purification. Based on this background, we previously reported that employing a small amount of CeO2 calcined at 1000 °C (cal-CeO2) in Pt-based TWCs was one of the most effective approaches for improving the catalytic activity without increasing the amount of Rh and Pd [3]. The effect of cal-CeO2 was attributed to the higher redox performance and Pt dispersion derived from the strong interactions between Ce and Pt.

The MacPherson strut is a simple and common across all automotive’s front suspension of passenger cars. It is an independent suspension type, including a single suspension arm (spring and damper), an anti-roll bar and a lower arm. The MacPherson strut must have sufficient stiffness to support cornering force and fore/aft loads. Fatigue test of MacPherson strut suspension can be done in multiple ways. Most common method is laboratory testing/rig test. The objective of laboratory testing is to validate the MacPherson strut physically for all possible real-time events. Replicating all real-time events in lab environment is a challenging task. For many years this limitation was addressed through experience, however it has often led to either over or inferior design. The expected life span of automotive components like MacPherson strut varies considerably but it can be measurable in years/miles.

This paper is the fourth printed listing of the National Highway Traffic Safety Administration’s (NHTSA) center-of-gravity (CG) location measurements. The previous papers contained data for 1024 vehicles. This paper includes data for 448 additional vehicles tested as part of NHTSA’s New Car Assessment Program (NCAP) for the years 2009 through year 2020. The NCAP involves only the CG location measurement; so the vehicles listed in this paper do not have inertial data.

An indoor road-wheel facility at the Technical University of Gdańsk was used to study the noise emission from a variety of tires with different tread patterns. The tires were run both on a smooth steel drum and a drum covered by a replica road surface. All tread patterns were hand-cut to generate several families of simple treads with regular pitch for a systematic study of how groove design influences noise. Most of the observed, tread influenced phenomena could be explained by generation mechanisms such as radial vibrations induced by tread block impact, pocket air pumping and pipe resonances in the grooves. For instance, it was observed that, when speed increases, sooner or later the tread block impact frequency will coincide with the pipe resonance frequency and then generate excessive noise at that speed.