Search Results

Using data from the Fatality Analysis Reporting System, the National Automotive Sampling System's Crashworthiness Data System and General Estimates System, and combined state data from Idaho, Illinois, and Maryland, we examined crashes accompanied by fire. Vehicles weighing less than 10,000 lbs were analyzed, and were further categorized by type. Differences in fire rates were found in the examination of many of the factors reviewed. The distribution of fires occurring at various points of impact is different from the distribution of impact in all crashes. Crashes accompanied by fire occur more frequently after frontal collisions and are less likely to occur after side or rear impact collisions. The strongest indicator of fire is the amount of energy in the crash. Therefore, vehicle speed and the type of object or vehicle struck during the crash are relevant factors in collisions accompanied by fire.

Traditionally on-centre steering has been evaluated by a sine wave steering input through-centre. This method is widely used to characterise the on-centre steering characteristics of vehicles. Although it enables a wide range of key parameters to be quantified such as on-centre stiffness and hysteresis, the test does not encompass how the vehicle responds when an input is made from or returning to the straight running condition. The objective of this study was to propose additional on-centre evaluation methods that would include the response of the car from straight ahead running. A range of vehicles were then tested in accordance with these methods using a combined IMU/GPS system. The data from this testing was analysed to determine what measures might be useful in quantifying the response of a vehicle from straight ahead running. Then using the data obtained from this group of vehicles provide reference information on the upper and lower limits of these measures.

The realistic simulation of vehicle-trailer combinations and the development of controllers for vehicle trains require comprehensive models for the dynamics of vehicle and trailer as well as a numerically feasible representation of the hitch. While the equations of motion for the two chassis can be reduced to systems of ordinary differential equations, introducing the coupling yields additional algebraic constraints on the relative vehicle-trailer motion. In this paper, a numerical algorithm for the simulation of vehicle trains is presented which overcomes the stability and drift-off phenomena known from the treatment of differential-algebraic equations and achieves real-time capability. Numerical results from simulations with a commercial vehicle dynamics program are shown proving its effectiveness for different vehicle-trailer combinations and demanding driving maneuvers.

Recent rollover resistance test results show discrepancies between vehicles steered with programmable steering machines and those steered by test drivers. This paper examines the differences in steering profiles and their effects on vehicle dynamics. For decades, test drivers have steered vehicles through rollover resistance test maneuvers. Human inputs, however, can cause variability from test to test. The National Highway Traffic Safety Administration (NHTSA) is currently performing rollover testing with steering machines in an effort to objectively rate the rollover resistance of passenger vehicles. The trapezoidal steer inputs are visibly different from human inputs and may be responsible for test differences. The roll rate feedback loop, which determines steer timing, may also affect vehicle response.

Road simulators reproduce measured service environments in laboratory based test rigs and have contributed significantly to improving the structural integrity and quality of modern vehicles. These rigs are driven by data that are derived from a specified response and the frequency response function of the test rig in an iterative process. This paper introduces an alternative iterative procedure that converges to a valid drive file in fewer iteration steps than the current algorithm.

The durability and riding comfort performance of a new type scooter were investigated by bench test. The long-term road load data of Taiwan market were measured with accelerometers and strain gauges by the on-line rainflow cycle counting method. The equivalent test track corresponding to 50,000 km in Taiwan market was established with ARTC's proving ground (Automotive Research and Testing Center in Taiwan) by correlation analysis technique. Then we performed the full vehicle bench durability test with load histories obtained by the road simulation technique. After a series of testing, analysis, and modification, the test vehicle already got a satisfactory result for the durability performance. Riding comfort analysis was performed following the ISO 2631 standard with accelerometers near the seat and foot in the bench testing. In order to get an optimum combination of suspension system for this new type scooter, many sets of front and rear suspensions were evaluated.

Model-in-the-loop (MiL) testing refers to the scenario in which the test specimen is part real and part virtual, i.e. a physical sub-system is linked to a real-time computer simulation. Due to imperfect actuator behavior the hybrid test specimen will not respond in quite the same way as the real (complete) specimen would. In this paper the accuracy of the MiL system is assessed for two automotive testing examples: tire vertical dynamic emulation, and the emulation of aerodynamic forces. Linear models of racecar dynamics are used in the assessment, combined with real measurements of actuator response. The results indicate that considerable care is required in designing such test systems; the tire emulation results in particular are unacceptable.

The design discipline of Design For Six Sigma (DFSS) has been applied to many areas of product development and manufacturing. As DFSS application has recently been extended to upfront automotive engineering areas such as research and advanced development, more robust and optimized technologies can be achieved in the pre-production stage, reducing cost, exhibiting superior quality and performance, and shortened development cycle. This paper describes the application of the DFSS process, Define, Characterize, Optimize, and Verify (DCOV) to develop an automotive technology that begins from the conceptual phase and continues up through the implementation phase. The role of DFSS in the automotive industry is to provide a framework for more rigorous upfront engineering. It provides guidelines to a more effective and efficient development of new technologies.

Robust design methods are becoming widely adopted in automotive industries because of their cost- and time-efficiency for quality improvement in a vehicle development process. These methods were pioneered by Dr. Genichi Taguchi of Japan and introduced to the U.S. in 80’s. Typical Taguchi-class robust design approaches apply S/N ratios of various types to measure the robustness performance of the output responses of target systems. Next designed experiments are applied to identify key control factors and interactions to maximize the selected S/N ratio in order to make the systems insensitive to pre-selected noise factors.

Axle cover pan bolted joint sealing with a fiber composition gasket material can be challenging to achieve leak-free sealing. A project was conducted to optimize a stamped steel cover pan/fiber composition gasket static sealing ability by utilizing the Taguchi Robust Engineering method [2]. An analytical FEA modeling approach in combination with the Robust Parameter Design technique [1, 2] was utilized to evaluate and optimize the stamped cover pan crown embossment geometry shape.

A variable displacement engine with the capability to vary stroke length and compression ratio independent of one another has been designed, prototyped, and successfully operated. Reasons for investigation of such an engine are the potential for improvement in fuel economy and/or performance. Literature has shown that engines with variable compression ratio can significantly decrease specific fuel consumption. Engines with variability in stroke length can maintain peak efficiency running conditions by adjusting power output through displacement change verses through the efficiency detriment of throttling. The project began with the synthesis of a planar 2-dimensional rigid body mechanism. Various synthesis techniques were employed and design took place with a collection of computer software. MATLAB code performed much of the synthesis, kinematic, and dynamic analysis.

A fuel cell-battery hybrid powertrain SUV vehicle is designed using an optimized model-based design process. Powertrain and fuel storage components selected include a 65 kW Polymer Electrolyte Membrane Fuel Cell (PEMFC) power module, two 67 kW electric traction motors, a 35 MPa compressed hydrogen storage tank, a 70 kW nickel metal hydride battery pack, and a University of Waterloo in-house DC/DC converter design. Hardware control uses two controllers, a main supervisory controller and a subsystem controller in addition to any embedded component control modules. Two key innovations of this work include the hybrid control strategy and the DC/DC converter. The final powertrain characteristics are expected to meet a set of Vehicle Technical Specifications (VTS).

The purpose of this report is to describe the process for the development of the automatically shifting manual transmission control system hardware and software to be used in the MTU Challenge X Equinox, a through-the-road parallel hybrid electric vehicle. The automatically shifting manual transmission was chosen for development, as it combines the ease of use of an automatic transmission with the fuel efficiency of a manual, while eliminating the parasitic losses in the torque converter and the transmission hydraulic pump. This report illustrates the process used to develop the software-in-the loop modeling that was developed for the initial proof of concept. In addition, it describes the development of the control strategy and hardware build for the prototype transmission. To begin the design process research was preformed on existing automatically shifting manuals and manual transmissions in general. From there vehicle subsystems were assembled using Simulink block diagrams.

This paper describes the design and development of an engine with constant power for SAE's student Formula race-car competition, allowing the avoidance of gear shifting for much of the Autocross event. To achieve constant power for over 50% of the speed range, turbocharging was adopted with a boost pressure ratio of 2.8 at mid-range speeds and applied to an engine capacity of 430 cc. This engine was specifically designed and configured for the purpose, being a twin cylinder in-line arrangement with double overhead camshafts. Most of the engine components were specially cast or machined from billets. The capacity was selected to minimise frictional losses and thus increase delivered power along with dry sump lubrication and a three speed gear box. The engine manifolds and plenums were designed using a CAE application and proved to be well suited to the task resulting in excellent agreement between predicted and actual performance.

Today the technique of “primer less coating” has developed into a sophisticated method. Due to the missing primer, new parameters must be included in the quality ensuring process. One of these parameters is the wavelength-specific UV-transmission. The evaluation of the necessary film thickness is another fundamental factor for the determination of the light transmittance and is directly related to the resulting cost benefit. With a combination of these two parameters the minimum film thickness of a basecoat can be determined approximately. This data in combination with further values like maximum applicable spray made, ESTA (Electrostatic Application), and popping or sagging film thickness limits, the process window can be calculated.

Color design is playing a more important role recently when establishing automotive commercial value. High chroma TiO2 pigments which have less than 1/3 the aspect ratio of the current interfere pigments have been developed. Anatase type TiO2 pigments, which have high photo-catalytic activity can now also be used for automotive paints.

Waterborne coatings are being used more widely in the automotive industry due to their environmentally benign properties. As the rheological properties of the waterborne coatings are significantly different from most solvent borne coatings, paint circulation systems that are designed for solvent borne coatings are not necessarily well suited for waterborne coatings. It is possible to fully characterize the rheology of the waterborne coatings and make an optimized design of the paint circulation system, resulting in improved finish quality and reduced operating cost.

Physical properties of waterborne soft feel coatings for instrument panel were investigated. Soft feel coatings give warm and velvet touch for cold and hard plastic materials. A waterborne soft feel coating is composed of two parts. Part A contains polyester polyurethane dispersion (PE-PUD), OH-functional water dispersible polyurethane resin (PC-PUD) and OH-functional water dispersible alkyd resin (OH-PA). Part B contains hydrophilic hexamethylene diisocyanate trimer (HHDI). The soft feeling of a coated panel is related with the amounts of PC-PUD and OH-PA. The physical properties of coated panel are controlled by the NCO/OH ratio from Part A and Part B. The results from all reliability tests satisfied soft feeling, scratch, chemical resistance and fogging.

This paper presents a pioneer work and first time application of Multi Objective Robust Optimization to analytically improve Idle Shake Performance. The method is developed to obtain a robust design with multiple objectives under consideration along with managing material property variation. It was a Robust Optimization on top of Multi Objective Genetic Algorithm, Robu-MOGA. The design variables in the study included the nominal values and tolerances of Sound Transmission Loss property, and interior material Absorption property. The analytical objective was not only to minimize the peak airborne noise at each specified frequency, but also to reduce the total cost and the total mass of the materials. In the study, AutoSEA (statistical energy analysis) from ESI Software, Inc. was used as the solver. AutoSEA was integrated with iSIGHT from Engineous Software, Inc.

Materials used in automobile and motorcycle fuel tanks must provide good press formability and good seam weldability in addition to good internal and external corrosion resistance. Chromate-treated steel sheets, which contain Cr(VI), possess high corrosion resistance and have been successfully used for many years. Recently, however, Cr(VI) has been recognized as a harmful chemical which affects the human body. In reply to the social requirement of eliminating Cr(VI), Excelzinc Nickel GT has been developed to meet those requirements. Furthermore, Excelzinc GP accomplishes an excellent internal and external corrosion resistance in addition to the performance of Excelzinc Nickel GT by applying a gasoline-resistant resin layer for the tank inside and a lubricant resin layer for the tank outside. The properties of these new products meet all requirements for fuel tanks.