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Journal Article

Validation of Event Data Recorders in High Severity Full‑Frontal Crash Tests

This study evaluates the accuracy of 41 Event Data Recorders (EDR) extracted from model year 2012 General Motors, Chrysler, Ford, Honda, Mazda, Toyota, and Volvo vehicles subjected to New Car Assessment Program 56 kph full-frontal barrier crash tests. The approach was to evaluate (1) the vehicle longitudinal change in velocity or delta-V (ΔV) as measured by EDRs in comparison with the high-precision accelerometers mounted onboard test vehicles and (2) the accuracy of pre-crash speed, seatbelt buckle status, and frontal airbag deployment status. On average the absolute error for pre-crash speed between the EDR and reference instrumentation was only 0.58 kph, or 1.0% of the nominal impact speed. In all cases in which the EDRs recorded the seatbelt buckle status of the driver or right front passenger, the modules correctly reported that the occupants were buckled. EDRs reported airbag deployment correctly in all of the tests.
Technical Paper

Feasibility of Modeling Lane-Change Performance

This paper examines the feasibility of using four driving states (low risk, conflict, near crash, and crash imminent) to characterize lane-change driving performance. Data are analyzed from a test track study to estimate the boundaries between the states and to show that performance maps can be created for lane-change events in two simple scenarios. The map structure is further investigated using naturalistic on-road data and the agreement between the test track and on-road data models is discussed. Implications for crash counter-measure development and evaluation are discussed.
Technical Paper

Shock Loading Experiments and Requirements for Electric Wheel Motors on Military Vehicles

The University of Texas at Austin Center for Electromechanics (UT-CEM) has conducted a set of simulations and full-scale experiments to determine suitable shock load design requirements for in-hub (wheel) propulsion motors for hybrid and all-electric combat vehicles. The characterization of these design parameters is required due to recent advancements in suspension technology that have made it feasible to greatly increase the tempo of battle. These suspension technologies allow vehicles to traverse off-road terrains with large rms values at greater speeds. As a result, design improvements for survivability of in-hub motors must be considered. Defining the design requirements for the improved survivability of in-hub motors is the driving factor for this research. Both modeling and experimental results demonstrate several realistic scenarios in which wheel hubs experience accelerations greater than 100g, sometimes at very low vehicle speeds.
Technical Paper

A Quantitative Method for Accurately Depicting Still Photographs or Video of a Night-Time Scene Utilizing Equivalent Contrast

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.
Technical Paper

High-Performance Rear- and Mid-Engine Vehicle Exhaust System Temperatures

Hot surface ignition of combustible material is a known cause of vehicle fires. Although the detailed mechanisms of hot surface ignition are highly complex, the surface temperature is known to play a crucial role in this process. There has been limited previous work in the literature on this topic, much of which has focused on engine or exhaust system surface temperatures of the most common types of passenger vehicles. Also, much of this work was done in an unrepeatable manner and suffered from measurement technique induced errors. The focus of the present work is on repeatable and low measurement technique induced error temperature measurements of exhaust system surface temperatures of rear- and mid-engine sports cars. Temperature measurements were made at several points along the exhaust systems of vehicles both with and without turbo chargers on a 5-mile oval track.
Technical Paper

Simulation of Vehicle Pothole Test and Techniques Used

During the service life, the impacts of vehicle against potholes result in damage for the wheel and suspension components. Knowing the internal forces generated in the suspension components during this event would helpful to design the critical components. Measurement of these loads in physical test is more costly and not feasible for new designs. There are several virtual tools and methods available to predict the loads during this event. Using the ABAQUS FE solver, the non-linear dynamic behavior could be captured accurately during the impact. The tire model plays an important role during this event by absorbing energy during the impact. The CAE tire model is validated with some physical tests results and it is used in the vehicle pothole impact simulation. In vehicle pothole physical test, the force and acceleration measurement are taken and compared with the CAE results. The effect of the tire pressure variations and the vehicle speed at pothole impact is also studied.
Technical Paper

Evaluation of Spark-Ignited Kerosene Operation in a Wankel Rotary Engine

Wankel rotary engines (REs) are often used for unmanned aerial vehicle (UAV) applications due to their excellent power-to-weight ratio and their smooth operation. Existing RE propulsion units are mainly designed to run on high-volatility fuels like aviation gasoline or regular gasoline. However, specific applications require a jet fuel or even multi-fuel capability. Due to their geometry, the low compression ratio (CR) of REs prevents the implementation of compression ignition (CI) combustion processes. While publications of modified spark-ignition engines that are able to run on low-volatile fuels are already few in number, publications of heavy-fuel spark-ignited (SI) REs can hardly be found at all. The purpose of this paper is as follows: The operation of a SI RE operated on kerosene is discussed. Accordingly, a thermodynamic analysis is carried out at warmed-up operation with kerosene.
Technical Paper

Decelerations for Vehicles with Anti-lock Brake Systems (ABS) on Dry Asphalt and Concrete Road Surfaces

Anti-lock brake systems (ABS) produce high levels of vehicle deceleration under emergency braking conditions by modulating tire slip. Currently there are limited data available to quantify the mean, variance, and distribution of vehicle deceleration levels for modern ABS-equipped vehicles. We conducted braking tests using twenty (20) late-model vehicles on contiguous dry asphalt and concrete road surfaces. All vehicles were equipped with a 5th wheel sampled at 200 Hz, from which vehicle speed and deceleration as a function of time were calculated. Eighteen (18) tests were conducted for each vehicle and all tests were conducted from a targeted initial speed of 65 km/h (40 mph). Overall, we found that late-model ABS-equipped vehicles can decelerate at average levels that vary from about 0.871g to 1.081g across both surfaces, and that deceleration levels were on average about 0.042g higher on asphalt than on concrete.
Technical Paper

A Robust Methodology to Predict the Fatigue Life of an Automotive Closures System Subjected to Hinge and Check Link Load

In order to provide an accurate estimation of fatigue life of automotive door hinges and check strap mounting location, it is crucial to understand the loading conditions associated with opening and closing the door. There are many random factors and uncertainties that affect the durability performance of hinge and check strap mount structures in either a direct or indirect way. Excessive loads are generated at the hinge and check arm mounting region during abuse conditions when opening the door. Repeating the abuse conditions will lead to fatigue failures in these components. Most influencing parameter affecting the fatigue performance for the door was the loads due to hinge-check arm sensitivity stoppage and the distance between hinge and check strap attachments. However, the probability of occurrences was low, but the impact is high.
Technical Paper

The Cornering Compliance Concept for Description of Vehicle Directional Control Properties

The automobile directional control system is not easily simplified and the description of its design or engineering properties has necessarily been complex. In this paper, a concept for combining vehicle design parameters into two terms, and rear cornering compliance, is proposed. Analysis and simulation results are presented to illustrate the correspondence between the front and rear cornering compliance parameters and vehicle steady state and transient responses. The results indicate that the cornering compliance approach is reasonably accurate, easily understood and complementary to existing directional control theory and conventions.
Technical Paper

Friction Applications in Accident Reconstruction

The determination of appropriate friction coefficient values is an important aspect of accident reconstruction. Tire-roadway friction values are highly dependent on a variety of physical factors. Factors such as tire design, side force limitations, road surface wetness, vehicle speed, and load shifting require understanding if useful reconstruction calculations are to be made. Tabulated experimental friction coefficient data are available, and may be improved upon in many situations by simple testing procedures. This paper presents a technical review of basic concepts and principles of friction as they apply to accident reconstruction and automobile safety. A brief review of test measurement methods is also presented, together with simple methods of friction measurement to obtain more precise values in many situations. This paper also recommends coefficient values for reconstruction applications other than tire- roadway forces.
Technical Paper

Chrysler Corporation's New Hemi Head High Performance Engines

This paper covers the design and development of a family of engines used for closed circuit track competition and acceleration trail competition. In addition, a detuned version of the engine suitable for normal street and highway driving is described. All these engines share a hemispherical combustion chamber using push rod operated valves.
Technical Paper

The Influence of Vehicle Design Parameters on Characteristic Speed and Understeer

Vehicle understeer is rigorously defined and discussed as it pertains to directional control of an automobile. Methods are presented for predicting understeer quality in proposed vehicle designs and for measuring understeer quality in existing vehicles. The methods make possible complete and accurate quantitative descriptions of vehicle understeer.
Technical Paper

Warranty Repairs Reimagined through Machine Learning and Statistical Pattern Recognition (Part 1)

The automotive industry has been funding warranty repair work for many decades. The most common vehicle warranty is 3 years or 36,000 miles [1]. Original equipment manufacturers (OEM) in North America have dealers record all the work completed and submit claims for the work that qualifies for warranty reimbursement [2]. The OEM reviews the request and pays dealers for the work performed. In addition to payments, the database is also used to complete quality analysis for the vehicles. Often the software being used by dealerships is old and not designed for quality analysis. Reviewing all the warranty work done can be an arduous task. OEMs can receive 100,000 or more claims each day. To speed up the analysis process the OEMs will divide the repair work into sections based on the segment of the vehicle requiring work. This categorization allows the OEMs to spread the work across many experts in the company. But what does the OEMs do when the problem cannot be located at the dealership?
Technical Paper

The Design of a 4 Wheel Steer-4 Wheel Hydrostatic Drive All-Terrain Vehicle for REV-74

Recreational Ecological Vehicle (REV) 74 was an intercollegiate All Terrain Vehicle (ATV) design competition organized by the Milwaukee and Cincinnati Sections of SAE. Students from six colleges built ATV's to compete May 30-June 1, 1974 at Michigan Technological University's Keweenaw Research Center test course. Competing categories of noise level, destructiveness to terrain and a 25 mile race over land and water are discussed from the viewpoint of the technical rules and as to the actual course involved with the competition. Michigan Tech designed and built a 4 wheel steer-4 wheel hydrostatic drive ATV for REV-74. This paper provides a detailed design description of the Michigan Tech vehicle along with a review of several production ATV designs and their specifications. Finally, a report of the results of REV-74 is presented.
Technical Paper

Development of Robust Traction Power Inverter Residing in Integrated Power Electronics for Ultium Electric Vehicles

General Motors (GM) is working towards a future world of zero crashes, zero emissions and zero congestion. It’s “Ultium” platform has revolutionized electric vehicle drive units to provide versatile yet thrilling driving experience to the customers. Three variants of traction power inverter modules (TPIMs) including a dual channel inverter configuration are designed in collaboration with LG Magna e-Powertrain (LGM). These TPIMs are integrated with other power electronics components inside Integrated power electronics (IPE) to eliminate redundant high voltage connections and increase power density. The developed power module from LGM has used state-of-the art sintering technology and double-sided cooled structure to achieve industry leading performance and reliability. All the components are engineered with high level of integration skills to utilize across TPIM variants.
Technical Paper

Chrysler Corp.'s New 273 cu in. V-8 Engine

A new 273 cu in. V-8 engine for use in the Plymouth Valiant and Dodge Dart car lines is described. It combines increased smoothness and performance with the maneuverability characteristics of a compact car. This paper describes the design features of this engine and reviews briefly the factors which provide the engine with a high level of reliability and performance.
Technical Paper

Digital Cockpit in the Era of the Software-Defined Vehicle

The next generation of digital cockpits requires modern architectures to be successful and affordable. This paper provides an in-depth view on the future of digital cockpit architectures. The currently emerging architectures are explored with two main points in focus: The key experiences that drive customer expectations and the options to cost-effectively meet those expectations—while keeping the vehicle affordable. Modern architectures rely on middleware services. Well-designed middleware services allow for an efficient and reusable approach across different model lines and market segments. The paper presents this approach. The new architectures also lead to a transformation of the partner ecosystem between original equipment manufacturers (OEMs) and component suppliers. OEMs try to lever this system while maintaining control over their offerings. These changes transform the traditional semiconductor industry as a whole.
Technical Paper

Evaluating Fire Propagation into the Passenger Compartment via Full-Scale Burn Testing

Two full-scale burn tests were conducted to evaluate the propagation of an engine compartment fire into the passenger compartment of consumer vehicles. In particular, the effect of penetrations in the bulkhead separating the engine compartment from the passenger compartment was examined. The first burn test involved two vehicles of the same year, make, and model. One of the vehicles was left in the original equipment manufacturer (OEM) configuration. The other vehicle was modified by welding steel plates over the pass-through locations in the bulkhead between the engine and passenger compartments. After the fire was initiated in the engine compartment and had reached the onset of flashover, the heat and flames from this fire began to effect the passenger compartment. At about this same time, flames extending from the engine compartment around the hood began impinging directly on the outer face of the windshield.
Technical Paper

Origins of the F-22 Raptor

The F-22 will be the primary US Air Force air superiority fighter through the first quarter of the 21st century. The F-22 emerged from the Advanced Tactical Fighter (ATF) program. The Concept Definition (CD) phase of the ATF program began in November 1981. ATF Demonstration and Validation (D/V) was initiated in October 1986 with F-22 Engineering and Manufacturing Development (EMD) starting in August 1991. First flight of the EMD F-22 occurred on 7 September, 1997. The F-22 will enter operational service in the year 2005. This paper traces the ATF's developmental history from its earliest beginnings in the 1970s through the CD phase to the formal start of D/V at the end of 1986.