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Lightweight “drag sleds” have long been used by crash investigators to determine the “drag factor” at a crash scene. Despite this long history, no published work has ever shown a correlation between drag sled results and the skidding performance of vehicles on multiple “uncalibrated” surfaces. Indeed, some researchers have noted that their testing appeared to show a poor correlation between the two. It has become clear in recent years that the interaction between braking or skidding tires and pavement does not fit the simple weight- and speed-independent friction model that has been assumed, leaving the accuracy of drag sleds in doubt. This paper presents the results of several comparison tests at different locations, involving multiple skid-test vehicles, dozens of drag sleds of various designs, and more than a hundred “pullers,” and attempts to correlate the results of the two methods.

The costs of low-velocity, front-to-rear crash tests include the bullet (striking) and target (struck) cars. Analyses of this type of tests led us to conclude that it may be technically feasible and economically advantageous to replace the bullet car with a simplified mechanical device. A bifilar pendulum with an impact face consisting of a mass-spring-damper system was designed to simulate the bullet car in car-to-car, collinear, low-velocity (delta-v <= 8 km/h) front-to-rear tests. The elements of the pendulum face were evaluated dynamically and quasi-statically. Also, car-to-car tests were initially performed with stationary target cars (brakes off). Repair or replacement of the minor damage observed in the cars was accomplished as needed. Tests were subsequently performed with the pendulum striking the same target cars and approximating the bullet cars' impact energies. The pendulum, bullet, and target cars were instrumented with translational acceleration and velocity sensors.

Lead is well recognized as having environmental and health risks. The elimination of lead from automotive components has been accelerated by the European End of Life Directive as well as litigation concerns in the U.S. In response to these circumstances, two new lead-free bronze materials have been developed as replacements for SAE 792 (CuSn10Pb10). The two lead free materials are sintered bronzes with nominal compositions CuSn10Bi3 and CuSn8Ni. The characteristics and performance of these materials are compared and contrasted to sintered and cast SAE 792. Fatigue strength, mechanical properties, corrosion resistance, and wear resistance are described and related to the microstructural and application conditions. The CuSn10Bi3 material is preferred for SAE 792 applications having poor lubrication or high-speed conditions, typically in spark ignition connecting rod bushings or highly loaded transmission bushings.

A three-dimensional CFD methodology has been developed and applied to predict the pump performance, to understand pump flow dynamics, and to investigate pump flow/pressure ripple for gerotor pumps equipped in automatic transmission systems. The methodology is based on the commercial code CFD-ACE+ and the analytical focuses are the flow cavitation and pressure ripples over a wide range of engine speeds, 500rpm to 6,000rpm. The CFD results are first compared with the hardware measurements and a very good agreement has been achieved. Extensive CFD simulations are then conducted to study the effects of the inlet pressure, tip clearance, porting and the metering groove geometry on pump flow performance and pressure ripples.

Fire safety is an important issue on any vehicle. Generally vehicle occupants and flammable materials are in close proximity and it is not always easy or practical for the occupants to move away in the event of a fire. A properly designed on-board, pre-engineered fire protection system can significantly mitigate the effects of a vehicle fire, including saving lives and reducing property losses. But such fire protection systems may not be appropriate for all vehicles. In any case, a properly designed system depends on the threat being well understood. Additionally, vehicle real-estate tradeoffs-including weight, size, cost and environmental factors-must be considered. When a fire protection system is appropriate, the type and configuration of the optimum system varies widely and will depend on the vehicle and its intended use.

Accident investigators are often required to determine if an occupant was wearing their seat belt during a collision. Previous studies have provided examples of physical evidence relied upon by investigators to determine if the seat belt assembly was subjected to occupant restraint loading. This paper examines the potential for clothing fibers to be permanently transferred to the seat belt webbing during a collision. To evaluate fabric transfer evidence as an indicator of restraint usage by an occupant during a collision, the following issues were examined: automotive seat belt webbing construction and behavior under load, fiber evidence found on the webbing in new and used conditions, and the transfer of different types of clothing fibers to webbing during full-scale sled testing.

Due to the known hazard of ignition of flammable and combustible liquids by hot surfaces, recent studies have been conducted to better understand the influence of various effects such as orientation of the hot surface, its size, surface material, and the residence time of flammable vapors near the hot surface. In this study, tests were conducted with gasoline and other flammable fluids using a hot surface to determine the relative influence of volatility, as represented by boiling point, and the Minimum Auto Ignition Temperature (AIT) (ASTM E 659) on the hot surface ignition temperature. We present the results from over 1,000 ignition tests that were carried out using a highly reproducible test protocol that includes a circular hot plate section. The experimental hot surface was not designed to represent any specific automobile component nor does it necessarily represent the conditions that exist in the engine compartment after an impact.

This paper presents new aspects of the casting and manufacturing of BMWs inline six-cylinder engine. This new spark-ignition engine is the realization of the BMW concept of efficient dynamics at high technological level. For the first time in the history of modern engine design, a water-cooled crankcase is manufactured by magnesium casting for mass production. This extraordinary combination of magnesium and aluminium is a milestone in engine construction and took place at the light-metal foundry at BMW's Landshut plant. This paper gives a close summary about process development, the constructive structure, and the manufacturing and testing processes.

Thermal shock performance parameters to assure Ultra Thin Wall (UTW) substrate durability for close-coupled (CC) converter operating conditions have been defined through testing and FEM modeling. Propane burner tests simulating the engine exhaust conditions were performed and coordinated with FEM stress analysis. For the stress analysis, a newly developed Macro-Micro Thermal Stress Analysis method was employed. Validation of the Macro-Micro Thermal Stress Analysis method was made through comparing FEM analysis results with the electric furnace and the burner tests results. A thermal fatigue life prediction method taking into account variation in material strength, fatigue degradation and effective volume was developed. In the verification tests, crack generation stresses were predicted within a 20 % margin of error.

Recently, catalyzed soot filters (CSF) for passenger vehicles have been introduced into the marketplace to comply with the European environmental requirements and future emission standards. The initial system consisted of one or two diesel oxidation catalysts (DOC) to meet the regulated HC and CO standards along with an under floor CSF to treat the particulate emissions. In order to meet the cold start requirements and to reduce system costs with a CSF only unit, converters are placed closer to the engine to minimize heat losses and more of the DOC functionality is integrated into the filter substrate. This work describes the development of such DOC-integrated CSF systems. One major challenge in the design of such systems is to ensure that there is sufficient catalyst functionality within the wall-flow substrate while maintaining an acceptable exhaust gas backpressure across the filter.

The “Range-of Motion of the Cervical Spine of Children” study is a collaboration between Kettering University and McLaren Regional Medical Center in Flint, Michigan to quantify and establish benchmarks of “normal” range of motion (ROM) in children. The results will be analyzed to determine mean and standard deviation of degrees of rotation and used to improve the occupant protection in motor vehicles, sports equipment and benefits of physical therapy. The data will be invaluable in the development of computational models to analyze processes involving children in motion.

Children who are too large for harness restraints but too small to obtain good restraint from a vehicle seatbelt alone should be seated in a belt-positioning booster. Boosters have been shown to significantly reduce abdominal injuries caused by seatbelts. This effectiveness may be due in part to the fact that boosters reduce the effective seat cushion length, allowing children to sit more comfortably without slouching. NHTSA recommends that children who do not use harness restraints use boosters until they are at least 145 cm tall. In this paper, data from several sources were combined to assess how well children fit on rear seat cushions. Data from NASS-GES were analyzed to determine the age distribution of rear-seat occupants. Anthropometric data from several sources were analyzed to determine the distribution of buttock-popliteal length, a measure of thigh length that is a key determinant of seat fit, as a function of age and gender.

Diesel Particulate active Reduction system (DPR) is a system that traps particulate matter in diesel exhaust gas with a particulate filter and actively regenerates the filter when PM accumulates to a specific level. In 2003, DPR was installed on Hino's light-, medium-, and heavy-duty diesel engines, and about 50,000 units of these DPR-equipped diesel engines are currently on the market. This paper reports results of further progress made on optimization of the active regeneration function of DPR. The goal of successful development of DPR is to optimally control the system under various engine-operating conditions to regenerate the filter without producing abnormal combustion of PM and to minimize the amount of unburned PM to keep the filter from clogging. To improve the control of DPR, the combustion phenomena of PM collecting on the filter were studied through visualization, and the factors influencing combustion were determined.

It has been reported that particulate emissions from diesel vehicles could be associated with damaging human health, global warming and a reduction in air quality. These particles cover a very large size range, typically 3 to 10 000 nm. Filters in the vehicle exhaust systems can substantially reduce particulate emissions but until very recently it was not possible to directly characterise actual on-road emissions from a vehicle. This paper presents the first study of the effect of filter systems on the particulate emissions of a heavy-duty diesel vehicle during real-world driving. The presence of sulfur in the fuel and in the engine lubricant can lead to significant emissions of sulfate particles < 30 nm in size (nanoparticles).

A promising technology for active safety is “X-by-Wire”, where mechanical and electromechanical components are replaced by electronic functions. One of the reasons for this is to have more than the driver input in the command chain, and also include some degree of intervention by the control system in case the driver behaviour is likely to put the car at risk. The adoption of a small number of computing nodes is a clear trend in vehicle design. A wide range of functions that are now distributed in the form of separate modules will instead be integrated. This approach will overcome the physical constraints of electrical and mechanical components and the costs of many separate electronic modules with their own power supplies.

As systems necessarily become more integrated and increasingly complex through market demands for more features, technical risks and therefore business risks increase. It becomes correspondingly harder to show that the properties desired of these Systems of Systems (SoS) actually hold under normal or abnormal operation. In particular, it is hard to detect emergent properties of a SoS because properties of individual systems are not necessarily compositional, especially during failure. This paper describes the objectives of a project addressing the problem of Dependable System of Systems and other related research in the field of Automotive Electronics. The capability being developed is based upon the scalable ‘Assumption-Commitment’[1] paradigm so that it can be applied to large and complex systems of systems.

Advancements in high-power semiconductor technology have opened new avenues for application of power electronics converters in safety critical applications such as in a hybrid vehicle automotive power system. Faults occurring in such application specific solid state converters can lead to fatal consequences as compared to their mechanical counterparts. This paper discusses the use of statistical moments to detect and identify faults. Existing system current and voltage sensors are used without the need for any additional sensors. The technique not only detects system malfunction, but provides information on the device under fault and the nature of the fault. An accurate knowledge of the same will allow appropriate action to be taken to avoid propagation of fault that may lead to catastrophic failure.

Embedded controllers and digital signal processors are increasingly being used in automotive safety critical control systems. Controller integrity is a significant concern in these systems. Over the past decade, several techniques have been published about controller safety and integrity verification. These techniques include: single processor with watchdog, dual processors, dual core processor, and asymmetric processor (intelligent watchdog). Each of these techniques have benefits, however, many new non-distributed safety-critical systems are applying the asymmetric processor technique to help verify controller integrity. This paper discusses an overview of five controller integrity techniques, and then provides a detailed discussion of an asymmetric processor approach. This paper presents two different options within the asymmetric processor approach.

Many next-generation automotive control systems, such as brake-by-wire, will feature the replacement of mechanical linkages between the driver and vehicle actuators by sensors communicating with computer-controlled electromechanical actuators. For such systems, redundancy is often employed to achieve the required fault tolerance and reliability. In this paper, we investigated the effect of hardware redundancy on the timing, control performance and reliability of an automotive drive-by-wire system. From an initial, minimal system design, we then added redundancy to provide fault-tolerance in the most critical areas of the system. To investigate if the software architecture had an influence on the effects of this redundancy, we implemented two different approaches to the software design for each implementation. We then used a Hardware-In-the-Loop (HIL) testing facility to record performance metrics for each of the four implementations. These metrics are presented and discussed.

When developing new automotive systems a great deal of the development effort is devoted to ensure a sufficient functional safety of the system. A question that arises during early risk analyses of such a system is that of the controllability of possible system hazards. While this question is answered in early stages very often using worst-case risk graphs, the question comes back later in a much more precise way: in case of active steering systems component failures would produce a deviation between desired and actual road wheel position, the deviation can be measured in terms of amplitude and/or time. The central question is how much deviation can be controlled by the driver? Note, that there will always be a certain, even small, deviation between desired and actual road wheel position since the steering systems controller contains feedback control algorithms aiming at minimising the regulation error but not actually making it disappear totally.