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The national goals of more fuel efficient automobiles are being achieved in part by smaller and lighter vehicles resulting in demands for smaller and compatible instrumentation. Previously designed towing dynamometers for regular-sized vehicles were unable to provide adequately low drawbar levels for small cars like the Chevette. The dynamometer trailer provides a controllable retarding force on the passenger car to simulate hill climbing. This paper describes electrical and mechanical characteristics and operation of a dynamometer specifically designed for contemporary vehicles. An improved method is outlined for supplying controlled electrical power to eddy-current retarders used on the dynamometer. The improved system uses a 24 volt production alternator to supply controlled direct current to the eddy-current retarder. The current delivered to the eddy-current retarder is controlled by adjusting the alternator's field current.

A study was conducted by the National Highway Traffic Safety Administration to determine the applicability of Federal motor vehicle safety standards to electric and hybrid vehicles. Addressed in the study were vehicles to be included in the demonstration fleets called for in Public Law 94-413 and vehicles anticipated for future consumer use. Descriptions are given of existing and future electric and hybrid vehicles,and results of safety tests are reported. It was concluded that Federal safety standards, with few exceptions, should be applicable to electric and hybrid vehicles, with the possible exception of special purpose, limited performance and use vehicles.

A 1975 California model automobile with an 8:1 C.R. 350 CID engine was modified by increasing the compression ratio to 9:1 which resulted in improved fuel economy. The higher NOx emissions were reduced to the base level by substituting a back pressure-controlled EGR unit for the original valve and increasing the EGR flow. Octane requirement was controlled by a knock sensor-actuated spark timing retard system. The knock sensor (accelerometer) is attached to one of the cylinder heads of the engine. When knock occurs, the vibration is picked up by the sensor, the signal is filtered to remove some of the engine background noise, and the knock pulse is detected. When the amplitude of the detected knock signal exceeds a threshold, the spark timing is retarded. When no knocking is detected over a waiting period, the timing is advanced back to its normal schedule.

This paper was prepared in connection with a broader study of the opportunities and risks associated with a demonstration program defined by the Congress of the United States in the Electric and Hybrid Research, Development and Demonstration Act of 1976. The paper develops estimates of the number of accidents, injuries, and fatalities which might result from introduction of electric and hybrid vehicles into the general passenger vehicle fleet. In order to derive such an estimate, we have referred to existing accident data banks for small internal combustion engine cars operating primarily in urban areas, and have extrapolated from that data to some assumed electric vehicle populations. In addition, we have considered some particular problems of electric vehicles which might produce new dangers, such as electric shock, battery acid, and low acceleration capability. The desirability of imposing existing or new safety standards on these vehicles is considered.

Crashworthiness aspects of two electric vehicles were evaluated in a modest test program. One vehicle was subjected to low-speed pendulum and barrier tests and static rollover. A second vehicle was subjected to a dynamic rollover using the procedure specified in FMVSS 208. Potential safety problems were exposed, and are addressed in the paper.

Future improvements in diesel engine fuel economy, while continuing to meet legislated emission standards, will require an increased understanding of the diesel combustion process. The fuel injection system plays a major role in establishing conditions before and during combustion; and, therefore, its contribution to the development of an optimum combustion system is important. This paper describes a mathematical simulation of the General Motors Unit Injector and its application to the combustion system development process. Simulation results are compared to test data from a comprehensive experimental program.

Two conventional gasoline powered four passenger coupes were converted to electric drive for use in the Ohio Department of Transportation (ODOT) motor pool. Compliance to applicable Federal Motor Vehicle Safety and anticipated Department of Energy Standards were desing goals. The implications for fire and shock hazards as well as dynamics compliance were considerations in the scope of effort. Techniques used and results of preliminary tests are reported. It was concluded that conversion of conventional vehicles to electric drive can be undertaken to achieve safety parity.

In recent years fuel injection systems have taken a more important place in the design of engines because of gaseous emissions, combustion generated noise and fuel economy considerations. Analytical studies to select and match fuel injection system components are becoming of increasing interest. This paper discusses an analytical approach to simplify the performance simulation of the fuel injection system. The analysis uses a modular approach for the system simulation, thereby reducing the programming effort particularly when components of grossly different designs are involved. Several examples are described to illustrate the use of this modular approach.

A new distributor type fuel injection pump for diesel engines up to 40 BHP/cylinder has been developed providing performance flexibility to achieve minimum gaseous emissions, and fuelling accuracy over a wide range of fuel temperatures and viscosities. The new metering system in the pump can consistently reproduce a desired maximum fuelling curve and is shown to be insensitive to injection nozzle variations. Excess fuel for starting and external maximum fuel adjustment are also provided. The paper describes the design and special features of the pump, and gives results of tests on rigs, engines and vehicles to demonstrate its performance.

A fault tree analysis is used to demonstrate the quantification of risk. The first step is the performance of a sensitivity analysis which gives an ordering of the critical components in the order of their importance. The second step is to quantify the failure probabilities of those components shown to be critical by the probit method using the applicable stress function. Component probabilities are reassembled with a data management program to obtain a quantification of the failure probability of the system. The costs incurred and/or saved in adjusting the system failure are coupled with probability to give a cost/benefit analysis.

This paper demonstrates the application of two stochastic methods for calculating system availability, reliability and downtime for an industrial system. The first method utilized is taken from the Markov process theory of system reliability modeling which allows the states of the system at any point in time to be modeled as a stochastic process. This procedure of stochastic system modeling is quite general and can be applied to many different system configurations, including series, standby redundant, parallel-redundant, maintained or nonmaintained. The method is applied to an industrial system consisting of subsystems in a series configuration together with a standby spare subsystem with repair maintenance. A critical requirement of the system studied is high availability, since it would eventually be placed in series in an automotive production line.

Historically the term Risk Analysis evolved from capital investment studies. However risk is inherent in product development, reliability and safety in addition to cost effectiveness analysis. Often classical probability distributions expressing risk are unavailable; and thus it becomes imperative to assess the personal probability distributions of technical experts. Features of three main assessment methodologies and their applicability for quantifying technological risk are discussed. Implementation procedures and the pitfalls to be avoided are outlined. Sample results of a case study for new product development, which were subsequently used as inputs to a decision and control model are presented.

In order for fault tree analysis (FTA) to be useful in the assessment and control of risk, the synthesis of the trees should be: 1) Routine -- so that project engineers, etc. will use it. 2) Rapid -- so that it won't slow down the project. 3) Accurate -- so that the results will have some meaningful relationship to the actual risk. 4) Flexible -- so that the synthesis procedure could be used on a wide range of systems. We present an algorithm which uses directed graph (digraph) models of the cause and effect relationships between variables and events. Given the models, the algorithm will deduce the combinatorially correct fault tree for the system. The models and the algorithm are described and tested on two examples.

The cornering properties of tires while a vehicle is traveling generate a curve different from those in steady state derived from prevailing tire-testing devices. The objective of this paper is to clarify the cornering properties in order to simulate vehicular motions and to make the results applied to practical use. This paper presents experimental data on steady-state tire cornering properties at slip angles of 0 to 90 degrees and on transient tire cornering properties up to relatively large slip angles. This research deals with transient tire cornering properties at slip angles of 0 to 90 degrees.

A scale model simulation is developed to study passenger car running performance. Emphasis is placed on a study of vehicle overturn according to drastic steering. Two model cars are used. They have suspensions, pneumatic tires, shockabsorbers and steer mechanism. As the tests are performed while coasting, they do not need the engine and drivetrain to test of the basic running characteristics, the model is continuously given the necessary speed by the rotational arm or by the full size cars. Especially, at J turn, they are shot by the catapult.

A new passenger tire designation system was originated by the International Standards Organization (ISO) and has been approved by the U.S. Tire and Rim Association, Incorporated (T&RA) and the National Highway Traffic Safety Administration (NHTSA). This paper explains this P metric tire designation system and compares it in regard to load formula, endurance and wear performance, and dimensional tolerance criteria to the current T&RA alpha designation system in use on most U.S. passenger car tires.

A “semi” anechoic room design has been proposed and constructed from readily available, inexpensive construction materials. To demonstrate its feasibility, noise testing was conducted using a rotary engine as the noise source. The results of the testing indicated that the design is functional since free field conditions exist. This condition was proven to exist for at least one angular position measured relative to the exhaust pipe and in the horizontal plane of the exhaust pipe. Other information is provided concerning engine behaviour and type of noise radiated.

This paper deals with high frequency noise in the passenger compartment which are caused by transmitted engine noise. For the purpose of noise reduction, several evaluation methods are developed. For the evaluation of a body transmission loss, a combination of a reverberant room and an anechoic room is used. The noise absorption of the compartment is evaluated under the concept of the saturated sound pressure level. And sufficient standard samples are measured to support the noise reduction development.

The engine is an important source of diesel powered vehicle noise, and becomes dominant after proper treatment of exhaust and cooling system noise at vehicle speeds below fifty miles per hour. This paper presents the results of a comprehensive study dealing with surface noise radiation characteristics and the ranking of sources on three truck diesel engines. A special acoustic facility constructed to emphasize the acquisition of diesel engine noise data is describad. Information is presented on measurement methodology and its viability for quantification of engine noise, directivity, and radiation patterns from engine surfaces. Acoustic measurements, conducted over a range of engine loads and speeds, include spectral analysis of the sound pressure field derived from a thirtytwo microphone spherical array. Various noise identification techniques are explored under comparative testing to ascertain potential candidates for quantification and ranking of engine external surface radiation.

In this paper, we have analyzed the problem of the engine noise propagation and have classified that there is a fundamental relationship between exterior noise and structural design. In the case of light vehicles, we have isolated the following 2 factors in structural design which have a direct bearing on exterior noise. (1) The layout and the area of exposed openings in the engine room. (2) The ability of the engine room to absorb noise. In conclusion we suggest comprehensive approach to the problem of automotive noise reduction.