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Technical Paper

Hardware-in-the-Loop Simulation as a Standard Approach for Development, Customization, and Production Test

1993-03-01
930207
Hardware-in-the-loop simulation may become a standard tool for the development of electronic or mechanical automotive components. A single component or even a whole vehicle can be replaced by mathematical models simulated in real time on small and cost-effective hardware systems, while other components which need testing or are just part of the test setup, are connected to the simulation in a closed-loop configuration. Increased experience and advances in software and hardware make this technology very attractive. Typical examples demonstrate how it can not only reduce field tests, but also make formerly unfeasible experiments practical. Some of the software and hardware issues are also discussed.
Technical Paper

Modeling Techniques Improve Ignition System Simulation Accuracy

1993-03-01
930206
Containing a mix of analog electronic, digital switching and mechanical elements, an ignition system can be considered an automotive “acid test” of simulator performance. Over the years, simulation technology has advanced to the point where various technology combinations can be accurately simulated, and interplay between the elements can be studied prior to prototype fabrication. This paper discusses the various aspects of modeling as applied to the simulation of ignition systems and offers suggestions for simulating other automotive applications.
Technical Paper

Challenges in Crash Simulation Due to Emerging Safety Standards

1993-03-01
930209
Automotive vehicle crash safety requirements have steadily become more stringent over the last decade. Automobiles of tomorrow have to comply with a host of requirements in various crash modes in order to be considered roadworthy. In the first section of the paper, the current major requirements, some important requirements that are imminent, and desirable requirements in the near future are briefly discussed. Until recently, crash requirements have been focused mostly on the vehicle structure rather than the occupant protection, with the exception of frontal crash. Scarcity of in-depth interpretation of accident data, lack of biofidelic injury assessment devices (“crash dummies”) and the necessity for test repeatability had kept the testing procedures simple. Often, crash testing involved statically loading the vehicle to measure the structural strength, without consideration of the dynamic behavior of the structure or the structure/occupant interaction.
Technical Paper

Investigation of the Net Safety Impact of an Occupant Protection System From All-Terrain Vehicles

1993-03-01
930208
This paper describes an experimental and epidemiological investigation of the potential application of a specific rollover occupant protection system, consisting of a rollover protective structure and occupant restraint (collectively referred to hereafter as ROPS), to all-terrain vehicles (ATVs). The ROPS investigated in this paper was proposed by Dahle [1987] as a means to improve the safety of ATV operation. Crash tests were performed with an unhelmeted instrumented dummy on 4-wheel ATVs equipped with the prototype Dahle ROPS (hereafter referred to as D-ROPS); the test results established that the D-ROPS design exhibited the potential for serious injury or death in lateral rollover, rearward pitchover, collision, and oblique frontal impact accident scenarios. Review of ATV-associated 1986 fatality reports from the U.S.
Technical Paper

Development and Test of a Dynamic Disengagement Device

1993-03-01
930212
Postcrash fires are a frequent cause of death in otherwise survivable automobile and aircraft accidents. The idea of the ICED (Internal Circuit Emergency Disconnect) battery [1] is to eliminate electrically ignited postcrash fires by means of an inertial interrupt device that will disconnect the active circuit at the battery if an accident should happen. The design of the prototypes that were tested and the analysis of the disengagement performance will be discussed. A ballistic pendulum impact test rig was designed and used to test the prototypes. The test results and analytical values were shown to be satisfactorily close to each other.
Technical Paper

Comparison of Premixed Turbulent Burning Velocity Models Taking Account of Turbulence and Flame Spatial Scales

1993-03-01
930218
Conventionally, turbulent burning velocity models are compared by showing the model-predicted ST/SL0 ratios in an ST/SL0 - u′/SL0 plane, where ST and SL0 are the turbulent and laminar burning velocities, respectively, with u′ being the turbulence intensity. Such a method applies to only those models which take u′ or u′/SL0 as the only variable of ST or of ST/SL0. In order to analyze and compare most recent models in which turbulence and flame spatial scales (or length scales) are also taken into account because of their importance in combustion, this paper showed the model-predicted ST/SL0 ratios as contours in three planes (Re-Da, ηκ/η0 - u′/SL0 and L/η0 - u′/SL0, where Re, Da, L, ηκ and η0 are the Reynolds number, Damköhler number, turbulence integral scale, Kolmogorov scale and laminar flame preheat zone thickness, respectively); these planes are usually used in discussing the flame structure.
Technical Paper

Impact Energy Management with Composite Materials

1993-03-01
930213
Much of the design and development of the modern automobile is dedicated to protecting occupants or reducing vehicle damage during and after a crash. Although the primary function of the vehicle body structure in this respect is to dissipate the kinetic energy of the vehicle, effective protection depends upon careful management of this energy in order to achieve the optimum collapse mechanism. For conventional metal components, the art of creating such “crashworthy” performance is now well understood. However, more and more vehicles are turning to polymer-based composite materials in their structures and these exhibit a totally different type of behaviour in the way that they dissipate energy to the metals which they replace. This paper reviews the fracture mechanisms of these materials, in relation to different impact speeds, as they affect the vehicle designer.
Technical Paper

A Numerical Computation for Vibration Displacements and Stresses of a Crankshaft with a Shear Rubber Torsional Damper

1993-03-01
930197
This paper refers to a numerical computation for vibration displacements and stresses of a crankshaft with a shear type rubber torsional damper by the three dimensional transfer matrix method. The accuracy of this computation method is confirmed by comparing computed results with measured ones. Especially, in this work, the numerical computation method is proposed to compute the vibration displacements and stresses by means of replacing the rubber part of rubber torsional damper with a spring-dashpot model. Then dynamic characteristics are estimated by the complex torsional stiffness derived from a three-element Maxwell model. As a result the torsional vibration stress and bending vibration stress and vibration displacements (angular and lateral displacements) can be computed with an adequate accuracy. This computation method is applicable to predicting the conditions of vibration displacements and stresses, and will contribute to optimum design of the crankshaft.
Technical Paper

Optimization of a Wastegate Turbocharged Medium Speed Diesel Engine

1993-03-01
930195
An eleven litre four stroke medium speed marine diesel engine has been studied with different wastegate turbocharging systems to improve low speed/part load engine performance. A previous Glasgow College model was adapted to simulate the engine operation under steady conditions. A variation to the Single Zone Fuel Model developed by Watson, Pilley and Marzouk was proposed and a Schwitzer-type wastegate turbocharger model was developed. A series of exhaust wastegate turbochargers have been simulated and tested to identify matching of the various turbomachinery configurations and the effects of these on engine performance. Both simulation and experimental results show that the wastegate bypass system can be modified to advantage by proper selection of the wastegate discharge flow mixing point along the engine exhaust system. The best low speed engine performance was obtained with the wastegate discharge flow exhausting directly to the atmosphere.
Technical Paper

Hardware-in-the-Loop Simulation - An Engine Controller Implementation

1993-03-01
930204
This paper describes a real-time engine simulation with an engine controller in the loop. The extremely high update rates needed to interface to the controller and the many types of signals required by the controller place great demands on the interface between the engine control unit and the digital simulation of the engine. The interface used to meet these demands is a distributed processor simulation system, the Applied Dynamics Real-Time Station. The interface system and the method used to schedule the processors to execute the engine hardware-in-the-loop simulation are described in this paper.
Technical Paper

A General Optimization Approach for Minimizing Acoustic Power Using Finite Elements

1993-03-01
930198
A general approach for minimizing radiated acoustic power of a baffled plate excited by broad band harmonic excitation is given. The steps involve a finite element discretization for expressing acoustic power and vibration analysis, analytical design sensitivity analysis, and use of gradient-based optimization algorithms. Applications to rectangular plates and an engine cover plate are presented. Thicknesses are chosen as design variables.
Technical Paper

Measurement of Fuel Injection Pump Sound Power Using Acoustic Intensity Techniques

1993-03-01
930200
Increasingly severe noise legislation and customer expectations for improved vehicle refinement continue to require fuel injection equipment manufacturers to reduce the noise generated by injection pumps. The measurement of injection pump noise or, more recently, sound power level has hitherto been carried out in anechoic or semi-anechoic chambers using purpose built quiet drive rigs which have themselves required continual quietening in order to allow accurate measurements to be made. The accuracy and speed of the measurements were improved some years ago with the development of the microcomputer based Lucas-CEL sound power analysis system. However, recent advances in acoustic intensity technology due to the ready availability of low-cost processing power has led to a re-evaluation of the measurement of pump sound power.
Technical Paper

Application of Acoustic Holography to Measurement of Noise on an Operating Vehicle

1993-03-01
930199
This paper describes a feasibility study of the acoustic holographic method to identify a noise source on an operating vehicle. A new acoustical holography method applicable to identification of a nonstationary noise source was assessed and developed. Based on the new method, a measurement system was made and applied to quantification of the noise source in the vehicle. The method was evaluated first for source identification capablity and confirmed by loudspeakers. The experimental approach was then applied to identify the location of vehicle tire noise under various steady state conditions. In this paper, an identification method of noise sources with relatively high power level is presented and the relationship between locations of tire noise sources under various operating conditions investigated.
Technical Paper

Simulation Techniques for Automotive Subsystems

1993-03-01
930205
There is a need for simulation to provide verification of an overall automotive system, with interacting components. Numerical methods for simulation in specific disciplines need to be understood and incorporated in the system-level framework. The paper surveys the state of the art for automotive subsystem simulation with emphasis on control applications.
Technical Paper

Active Engine Mount with Piezo-Actuator for Vibration Control

1993-03-01
930201
Abstract Electronics technology has made remarkable progress in recent years, and in the field of automobile noise and vibration control, it has attracted the interest of engineers due to its potential for use in the active control of vibration isolators. This report describes an investigation on reducing automobile vibration caused by engine explosion using a piezo actuator(PA) engine mount. Piezo actuator has a very high speed response but the displacement is generally very small. Therefore PA mount requires an amplitude enlargement mechanism. Here, an active mount with an enlargement mechanism incorporated was developed. For the control system, the adaptive control algorithm proposed by S. J. Elliott et al. was employed as a base, and a control rule against limitation in the power of the actuator was used in combination with it. A significant attenuation of the vibration of the dominant harmonic order in idling was achieved. The results are reported in the following pages.
Technical Paper

Evaluating Acoustical Performance of Expandable Sealant Materials

1993-03-01
930336
The use of sealant materials to improve interior acoustics has increased significantly in todays automobiles. One such application is to use expandable sealant materials in rails, pillars, and cavities to reduce noise propagation. However, there is no standardized method for evaluating the acoustical performance of these materials. This paper reviews the basics of noise control engineering and discusses a proposed laboratory based test methodology that has been developed for properly evaluating the acoustical performance or expandable sealant materials. The test method is intended to simulate actual applications so that different materials can be evaluated to achieve optimum acoustical performance within a channel representing the rails or pillars in automobiles.
Technical Paper

Induction Heating of Adhesives for Bonding of Thermoplastics and Composites

1993-03-01
930332
Structural adhesives have utilized different methods for accelerating cure and development of handling strength and final properties. These different methods have included fast curing chemistries, heated presses, microwave, radio frequency, high velocity hot air, and induction heating. Each method has particular advantages which the processor can use to maximize productivity and quality. This paper examines and reports on induction heating and its application for bonding of thermoplastics and composites. Induction heating has had good acceptance in bonding applications where metal substrates are involved. Automotive hem flange bonding has been a particularly successful application of induction heating. With metal bonding, the substrate is heated by the electromagnetic field generated by a current passing through an induction coil. Heating to cure temperatures occurs within fractions of a second and temperatures can easily surpass the limits of any organic adhesive.
Technical Paper

Adhesive Rheology and Dispensing Process Analysis

1993-03-01
930334
The rheological properties and dispensing characteristics of three reactive hot-melt adhesives were investigated in this study. Flow experiments were carried out in the temperature range from 60 °C to 110 °C. The Casson equation was used to represent the flow curves of the materials exhibiting an apparent yield stress and a plastic viscosity. The temperature dependence of the apparent yield stresses and the plastic viscosities of the reactive hot-melt adhesives were evaluated. Similar to epoxy paste adhesives, the yield stresses of the reactive hot melts are much less sensitive to temperature than the plastic viscosities. The sensitivity of the chemical cross-linking reaction was investigated using Differential Scanning Calorimetry. Processability of the reactive hot melt adhesives has been compared with that of the conventional paste materials using a quantitative model describing the paste material dispensing system.
Technical Paper

Sub-Zero Cold Starting of a Port-Injected M100 Engine Using Plasma Jet Ignition and Prompt EGR

1993-03-01
930331
This study describes the design and proof-of-concept testing of a system which has enabled sub-zero cold starting of a port-injected V6 engine fuelled with M100. At -30°C, the engine could reach running speed about 5s after the beginning of cranking. At a given temperature, starts were achieved using a fraction of the mixture enrichment normally required for the more volatile M85 fuels. During cold start cranking, firing is achieved using a high energy plasma jet ignition system. The achievement of stable idling following first fire is made possible through the use of an Exhaust Charged Cycle (ECC) camshaft design. The ECC camshaft promptly recirculates hot exhaust products, unburnt methanol and partial combustion products back into the cylinder to enhance combustion. The combined plasma jet/ECC system demonstrated exceptionally good combustion stability during fast idle following sub-zero cold starts.
Technical Paper

Research and Development of Hyundai Flexible Fuel Vehicles (FFVs)

1993-03-01
930330
This paper describes Hyundai's research and development work on a flexible fuel vehicle (FFV). The work on FFV has been conducted to evaluate its potential as an alternative to the conventional gasoline vehicle. Hyundai FFV described here can operate on M85, gasoline, or any of their combinations, in which the methanol concentration is measured by an electrostatic type fuel sensor. For that operation, a special FFV ECU has been developed and incorporated in the FFV. The characteristics affecting FFV operation, such as FFV ECU control strategy and injector flow rate, have been investigated and optimized by experiment. Various development tests have been performed in view of engine performance, durability, cold startability, and exhaust emissions reduction. The exhaust gas aftertreatment system being consisted of manifold type catalytic converter(MCC) and secondary air injection system has shown good emission reduction performance including formaldehyde emission.
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