Search Results

Statistical studies of collision and non-collision fires abound, founded upon information in publicly available collision and fire incident data bases. Recent efforts to improve the quality and reliability of the data within such databases have included the development of vehicle fire investigator training materials for motor vehicle crash investigators. These materials will be available to investigators both as a computer-based training system for remote learning and as a classroom seminar. When completed, the computer-based training course will be publicly available. The computer-based training course is based on published and unpublished research on vehicle fires, material properties and ignition characteristics. Topics include a discussion of combustible fluids and materials, ignition sources, burn patterns, arson, hybrid vehicles and vehicle design, as well as background information on fire science, automotive systems, and design and investigation standards.

This paper presents a platform-based approach for the design of System-on-Chips for safety-critical microcontrollers, in which a set of HW and SW IPs, tools and methodologies are used for detection and correction of faults affecting the different parts of the electronic equipment. The IEC 61508 norm has been used as guideline and a systematic validation methodology with fault injection is presented. The paper shows an application of this approach to a PHILIPS reference platform, and first results are given in terms of benefits and costs.

Developing robust algorithms for moving obstacle detection is a priority for autonomous ground robotic systems. This paper compares various techniques used for detecting moving objects from static and moving platforms and introduces two novel LADAR-based approaches for solving the problem of moving obstacle detection. Video based techniques including: codebook background subtraction, feature tracking and optical flow, and structure from motion are computationally more expensive than LADAR-based approaches and more susceptible to environmental factors, such as level of brightness in the image, as well as clutter and occlusion in scenes. In addition, LADAR-based techniques outperform video based ones when the objects to be detected are visually indistinguishable from the background, which is the case in many battlefield operations.

Time resolved intake runner flow field data is presented for a motored single cylinder four stroke, direct injection spark ignition (DISI) optical internal combustion (IC) engine with an optically accessible intake runner. Previous studies have shown the fundamental influence in-cylinder air motion has on engine performance, exhibiting a controlling factor on the mixing process and early flame kernel development. An improved understanding of the in-cylinder flow fields during the intake and compression process leading up to ignition is required. However, knowledge of the intake runner flow field during the intake phase of the engine cycle is required to establish the effect of intake runner flow variation on in-cylinder flow field development. This paper presents the use of a new time resolved digital particle image velocimetry system within the intake runner to study runner flows and their variation over many engine cycles.

Reflector designs using high-flux LEDs, with application to Daytime Running Lamp (DRL) and Front Turn Signal Lamp (FTSL), were presented at the 2005 SAE Conference[1]. In an attempt to further optimize system efficiency when using high-flux LEDs, we have studied additional reflector designs using Compound Parabolic Concentrator (CPC) optics. In this paper we will present results of such studies, and discuss reflector collection efficiency, overall system efficiency, and package size.

LED technology is becoming more established in exterior automotive lighting applications. For over a decade now LED’s have been considered to be standard light sources in CHMSL applications. During the last few years, rear combination lamps utilizing LED technology for stop, tail and turn functions have become increasingly available in the market. The recent development and availability of High Power white LED’s makes it possible, to design back up lamps, using white High Power LED’s as a light source. High Power LED technology just became available in late 2002, and was not proven in any automotive application. Photometric, thermal and electronic design was based on preliminary data sheets of this LED, and during the design phase, required a lot of flexibility and testing. OEM’s are continuously reducing the available packaging space for lamps.

In general, an LED headlamp consists of an optical system, an electrical system and a mechanical system. Conventionally, the optics of a headlamp is a classical illumination set, which includes a light source, a reflective mirror and/or a lens. In this research, the source simulation, a reflector design and the propotype are presented. The application ways of the LED headlamp prototype include fog lamps, low beam lamps and high beam lamps, and overall with a light distribution that approaches the ECE regulation. Presently, the AFS (Adaptive Front Lighting System) is one of the strongest areas of development for the headlamp design, and the LED headlamp with the AFS function will be the leading trend in the next generation. Therefore, the LED headlamp design and AFS function are integrated to produce the prototype of the AFS-LED headlamp. Finally, the study will show that an optical system to provide the applicable possibilities for the adaptive front lighting system (AFS).

The effect of vehicle acceleration history on dummy loading in the frontal impact NCAP event is explored with help of a one-dimensional mathematical model. Both numerical and analytical approaches are used to identify the ideal vehicle pulse. The numerical solution reveals limitations of square wave pulse. The analytical approach results in explicit formulation of the ideal pulse. Response of the mathematical model used in this paper is statistically correlated to a number of randomly selected NCAP frontal tests. Both the baseline model and the resulting optimized pulse are also confirmed using a validated three-dimensional Madymo model. Based on the analytical results, a simple measure of quality of the vehicle acceleration history is formulated.

One of the principal tools used by the accident reconstructionist to determine whether a vehicle occupant was properly restrained when an accident occurred is the examination and analysis of impact evidence and damage to interior structures of the vehicle. Careful analysis of such evidence not only assists in the determination of restraint usage, but can also provide insight into the pre-impact position of the occupant. However, the multi-faceted restraint systems and advanced materials used in modern vehicles can make the interpretation of vehicle interior damage difficult. This is especially true for impacts of mild or moderate severity, when interior damage may or may not be expected to occur, and the lack of any identifiable damage can be misinterpreted. In this paper, the restraint system damage resulting from a series of sled tests conducted at a range of mild to moderate impact severities with a normally positioned driver under various restraint conditions is discussed.

This paper describes an approach to simulate spindle coupled full vehicle durability tests for the purpose of completing virtual durability evaluations on components and full vehicles before a prototype is available. The reproduction of measured spindle loads was achieved on a virtual model of a passenger car coupled to a 4 Degree of Freedom (DOF) and 6 DOF spindle coupled test system. The tools and process improvements developed here will aid both test and analysis engineers in working closer together in solving their durability problems. By using Remote Parameter Control® (RPC®) technology in the virtual world, analysts have a new method to understand the virtual model by reproducing field-measured or generic road predicted signals for a variety of road surfaces. With newly created test rig models and a user friendly RPC™ iteration process, virtual testing that accurately replicates laboratory tests are now a reality.

This paper presents an empirical-based model which explains the force-deflection characteristics of disc stacks commonly used in automotive suspension dampers. The model provides tools for comparing different disc stacks to understand their effect on damper performance. Load-deflection data is presented on a variety of discs and combinations of discs. The data is analyzed to show how the diameter, thickness and relative position of discs in a stack can affect the stack stiffness throughout the range of disc deflections. A model is developed to show how changes in the disc stack will affect damper performance at different velocities. An example is provided that shows predicted changes in disc stack force-deflection characteristics and the resulting changes in a damper force-velocity curve. Ride results are also presented that confirm the validity of the model.

Phosphorus contamination from engine oil additives has been associated with reduced performance of vehicle-aged exhaust gas catalysts. Identifying phosphorus species on aged catalysts is important for understanding the reasons for catalytic performance degradation. However, phosphorus is present only in small quantities, which makes its detection with bulk analytical techniques difficult. Raman microscopy probes small regions (a few microns in diameter) of a sample, and can detect both crystalline and amorphous materials. It is thus ideal for characterizing phosphates that may have limited distribution in a catalyst. However, suitable Raman spectra for mixed-metal phosphates that might be expected to be present in contaminated catalysts are not generally available.

For vehicle fire investigations, the issue of gasoline hot surface ignition [HSI] on an engine component will arise. To address the concern usually two facts are required; the fluid's lowest hot surface ignition temperature for the vehicle conditions and the temperature of the component surface at the time of the fire origin. Three typical engine compartment surfaces were used to determine the HSI of gasoline; a nodular iron exhaust manifold, a stainless steel exhaust manifold, and a stainless steel heat shield. These components were used to conduct the bench tests for the typical regular and premium, summer and winter gasoline blends. Video tapes were used to acquire accurate autoignition temperature [AIT] data with thermocoupled parts. The investigation determined that the gasoline's HSI minimum values were dependent upon the materials used for the ignition surfaces rather than the grades of gasoline.

Recently there has been increasing interest in stationary vehicle fires (SVF) and the safety of vehicles parked in garages. This interest has grown out of allegations by insurance companies that garage fires, some of which spread to other parts of the residence and cause considerable damage and/or injuries, may be caused by vehicles, and hence the vehicle manufacturer should be liable for damages. Data from the National Fire Incidence Reporting System (NFIRS) 1999-2002 were used to study the involvement of motor vehicles in garage fires and to compare the risk of injury and fatality in post collision fuel fed fires (PCFFF) to risk of fatality in garage fires. This paper explores the role of both vehicles and other causes in garage fires. It is found that only 4.4% of garage fires in the US, or approximately 1,200 annual fires, are of the type that could possibly be related to vehicle design or maintenance.

In the present work, we study motorcycle dynamics under conditions where the motorcycle-rider combination encounters either a step or a channel parallel to the direction of travel. Analyses are presented from the points of view of geometric, analytical and experimental approaches. As with passenger cars and trucks which encounter so-called “edge drop-offs,” the results depend on the magnitude and shape of the step or channel, velocity of the motorcycle and control input(s) of the rider, if any. Results show than for many common disturbance situations, difficulties may be experienced by the rider.

Tests were conducted to evaluate the effects of the tire-induced vibration caused by a tread separating rear tire on the handling characteristics of a 1996 four-door two-wheel drive Ford Explorer. The first test series consisted of a laboratory test utilizing a 36-inch diameter single roller dynamometer driven by the rear wheels of the Explorer. The right rear tire was modified to generate the vibration disturbance that results from a separating tire. This was accomplished by vulcanizing sections of retread to the prepared surface of the tire. Either one or two tread sections covering 1/8, 1/4, or 1/2 of the circumference of the tire were evaluated. The results demonstrated that a tire modified with two bonded-on tread sections driven at half speed replicated axle tramp characteristics of a modified tire with a single bonded-on tread section at the peak axle tramp speed.

The selective catalytic reduction (SCR) based on urea-water-solution is an effective technique to reduce nitrogen oxides (NOx) emitted from diesel engines. A 3D numerical computer model of the injection of urea-water-solution and their interaction with the exhaust gas flow and exhaust tubing is developed to evaluate different configurations during the development process of such a DeNOx-system. The model accounts for all relevant processes appearing from the injection point to the entrance of the SCR-catalyst: momentum interaction between gas phase and droplets evaporation and thermolysis of droplets hydrolysis of isocyanic acid in gas phase heat transfer between wall and droplets spray/wall-interaction two-component wall film including interaction with gas phase and exhaust tube The single modeling steps are verified with visualizations, patternator measurements, phase-doppler-anemometer results and temperature measurements.

The effect of a Johnson Matthey catalyzed continuously regenerating technology™ (CCRT®) filter on the particle size distribution in the raw exhaust from a 2002 Cummins ISM-2002 heavy duty diesel engine (HDDE) is reported at four loads. A CCRT® (henceforth called DOC-CPF) has a diesel oxidation catalyst (DOC) upstream (UP) of a catalyzed particulate filter (CPF). The particle size data were taken at three locations of UP DOC, downstream (DN) DOC and DN CPF in the raw exhaust in order to study the individual effect of the DOC and the CPF of the DOC-CPF on the particle size distribution. The four loads of 20, 40, 60 and 75% loads at rated speed were chosen for this study. Emissions measurements were made in the raw exhaust chosen to study the effect of nitrogen dioxide and temperature on particulate matter (PM) oxidation in the CPF at different engine conditions, exhaust and carbonaceous particulate matter (CPM) flow rates.

This paper presents a new type of link for an engineered structure which combines a stamped metal component and an injection molded, thermoplastic part. The joining of the two dissimilar materials is accomplished during the injection using features already stamped into the metal component. This allows the structure to be lighter and cheaper than a structure assembled by fasteners. What will be highlighted in this document is the development of this specific link, from prototyping of the concept through the industrialization of the test samples, the concept validation and, finally the realization of a mass production part. A comparative study versus an existing technology will be shown to demonstrate the enhanced performance of this technology. Currently, the targeted application of this technology is a Front End carrier.

For the purposes of analyzing and understanding the general effects of a set of different vehicle attributes on overall crash outcome a fleet model is used. It represents the impact response, in a one-dimensional sense, of two vehicle frontal crashes, across the frontal crash velocity spectrum. The parameters studied are vehicle mass, stiffness, intrusion, pulse shape and seatbelt usage. The vehicle impact response parameters are obtained from the NCAP tests. The fatality risk characterization, as a function of the seatbelt use and vehicle velocity, is obtained from the NASS database. The fatality risk is further mapped into average acceleration to allow for evaluation of the different vehicle impact response parameters. The results indicate that the effects of all the parameters are interconnected and none of them is independent. For example, the effect of vehicle mass on fatality risk depends on seatbelt use, vehicle stiffness, available crush, intrusion and pulse shape.