Search Results

As the number of automotive control applications has increased, a need has arisen for a development system. This development system must allow the automotive engineer who is unfamiliar with electronic and computer technologies to conceive and evaluate control algorithm concepts with a minimum of design effort. Some basic interactive functions, which are common to most development efforts, should be incorporated into this unit. These interactive elements include a keyboard, display, and printer. The development system described in this paper provides a simplified means of program debugging, the capability to modify data and program functions during operation and evaluation, and the capability to accumulate and store evaluation data. The equipment associated with this development system is divided into two portions. One portion controls the vehicle operation and interfaces with the automotive sensors and actuators.

The mechanization of a single chip CMOS analog to digital converter is described using a pulse width modulator technique. A detailed block diagram is presented as well as important circuit considerations. Although the main objective was the integration of a 3 1/2 digit volt meter on a single monolithic device, the application of the technique to descrete solutions working in conjunction with microprocessors is briefly explored. In conclusion, the finished product, a 3 1/2 digit digital volt meter chip is presented briefly as an example of the practicality of the pulse width modulation technique.

A general treatment of the absorption of mechanical energy by the axial collapse of a variety of structural shapes, including tubes, honeycombs and foams is developed which encompasses both the geometry of the structure and also the material properties. The use of the method in the design of load bearing structures in which energy absorption is an additional design function is illustrated. High strength-to-weight ratio materials offer a significant weight saving for energy absorbing components, although such materials may have a reduced tensile ductility. The implications to situations in vehicle crashworthiness are discussed.

An urban area is an excellent laboratory to conduct vehicle accident investigations. The central city of Los Angeles, California and the entire city of Miami, Florida, will be the geographical areas discussed. These areas experience a large number of accidents in a relatively small geographical region and contain diverse numbers and types of vehicles, collision configurations, and accident severity levels, Figure 1. Within the designated urban area, the Accident Investigation (AI) team maintains close cooperation with all law enforcement agencies, along with many other federal, state and local agencies.

Employing the systems approach, an extended maintenance interval has been developed for the entire truck. Included are engine oil, gear oil, chassis grease, and the various filters required. Extensive laboratory and field testing was conducted in developing the various specifications and component configurations required to assure satisfactory performance and durability.

New instruments and techniques have made it possible to study particle morphology and composition to an extent not previously possible. The particulates in exhaust emissions and the particles resulting from engine wear are the two examples discussed in this presentation. In order to identify physical and chemical characteristics of diesel engine exhaust particulates, specialized sampling and analytical methods are required. Some of the techniques and instrumentation are presented along with typical results of exhaust particulate analysis. The particles of wear contained in engine lubricating oil provide information about wear mechanisms by utilizing new methods of analysis. The preparation of samples and the use of ferrography and scanning electron microscopy to analyze particle characteristics are illustrated as specific examples of wear analysis. This lecture is based on the work of Dr. John H. Johnson and several graduate students at Michigan Technological University.

High performance road and racing cars demand high performance from materials. Because high performance must be coupled with reliability, most constructors of such cars take a very conservative approach to materials selection, but some boldly break ground by using more advanced materials. Aluminum, magnesium and alloy steel are the most commonly used materials. Titanium, plastics and advanced composites are used by the more imaginative constructors. Here is a survey of materials specified by some of the builders of high performance road and racing cars.

Impedance Plethysmography was used to measure the perfusion changes and venous clearance in the lower leg, knee, thigh and buttock that was produced by operation of a pulsating seat cushion that may reduce the detrimental hemodynamic effects of prolonged driving. The grouped mean indices of arterial perfusion increased significantly (P < 0.05), in all segments studied, following a 5 minute activation of the seat cushion. The cushion assisted venous clearance in all segments of the leg during each inflation cycle. This device may be desirable to reduce fatigue and increase performance during prolonged driving.

Rising costs have increased the need for simplifying service. The response at Cummins Engine Company has been a program to improve the serviceability of engines, plus an effort to help equipment manufacturers make engines more serviceable in their installations. The program is a cooperative effort among several areas. Design criteria for improved engine serviceability are discussed. Key maintenance and repair operations are used as the basis for measuring and comparing the serviceability of engines. The method presented is flexible enough to allow various trade-offs to be made during the design stage. Guidelines for improved installation serviceability are outlined. The guidelines establish time limits for daily checks and routine maintenance, plus targets for service repairs. These are based on the times to perform the respective operations on free standing engines with allowances for installation considerations.

The paper outlines the OR trends of European and Japanese cars found in the European market place over the last five years. The consistently high proportion of critical models (at the 98 RON European Premium grade level) is highlighted, possibly reflecting the consequences of exhaust emissions and economy tuning brought about under the influence of tightening European legislation. However, the significant number of cars suffering from ignition over-advance is also investigated, this aspect being felt to be of increasing relevance. Whilst the importance of front end octane number as a gasoline parameter is shown to be declining slowly, the continuing large number of vehicles conscious, to a slightly increasing extent, of high sensitivity and/or olefin content is emphasized. Finally, the deleterious effect of lowering lead concentration is clearly demonstrated, particularly under the high engine speed conditions commonly encountered by small-engined European vehicles.

THE FIESTA, announced in July 1976, extends the European Ford model range by adding a new vehicle in the sub-compact class. The development of the FIESTA, to suit the market in North America and to comply with the motor vehicle safety standards of the United States and Canada, was completed in early 1977. The car was presented to the US public in May of that year. In part one of this paper the European version is described with special reference to those innovations which are of most interest in Europe. Part two deals with the North American version of the FIESTA with its specific requirements for comfort and conformity to safety regulations.

The fuel economy was sharply improved from our 1976 model rotary engine cars mainly through modifications to the engine and improvements in the reactivity of the thermal reactor system. The progress of our development on these items of improvement and their effects are presented in this paper. Our advance program includes several development items in addition to the above, and the progress of development on these items and their future prospects are also presented.

A model for predicting the performance and emissions characteristics of Wankel engines has been developed and tested. Each chamber is treated as an open thermodynamic system and the effects of turbulent flame propagation, quench layer formation, gas motion, heat transfer and seal leakage are included. The experimental tests were carried out on a Toyo Kogyo 12B engine under both motoring and firing conditions and values for the effective seal leakage area and turbulent heat transfer coefficient were deduced. The agreement between the predicted and measured performances was reasonable. Parametric studies of the effects of reductions in seal leakage and heat transfer were carried out and the results are presented.

In many rotary engines, over 10% of the fuel passes through the engine unused. This loss makes exhaust cleanup difficult and also represents a serious penalty in fuel economy. The major hydrocarbon sources were found to be apex seal leakage, cold wall zone effects, residuals and surface-to-volume ratio which included rotor surface quench and chamber surface quench. Lesser hydrocarbon sources were crevice volume, and effects attributable to spark plug, ignition system, turbulence, intake mixture and lubricant on the combustion chamber walls. Through various engine modifications we were able to cut base engine hydrocarbons about 55%.

At AUDI NSU a new generation of rotary engines has been developed of which the significant layout parameters are outlined. The present status of development is characterized by a lean burn concept with fuel injection and an exhaust emission control system with catalytic converter. Test results indicate that the fuel economy ranges at the same level as comparable reciprocating engines. The future US-exhaust emission standards are kept below but in respect to the Japanese standards further reduction of NOx is necessary. Endurance tests proving the durability of the exhaust emission control system have still to be performed.

During 1973, Oldsmobile planners concluded there would be a need for an engine with good emission capability and excellent fuel economy. After a study of alternate engines, they concluded that a diesel based on the Oldsmobile 350 gasoline engine would be the best answer. This paper reviews in detail: early diesel investigations conducted, combustion chamber development work leading to the General Motors 5.7 litre diesel, details of the production engine and modifications required to install it in the Oldsmobile passenger car. The final section reviews the future potential for diesels in the United States.

A new turbocharged 3.8 litre V-6 engine and powertrain has been developed for production application in the Buick model line-up. This design offers, as a replacement for larger displacement engines, a turbocharged powertrain with improved fuel economy and equal performance. Significant technological advances include engine-turbo matching for improved low end and mid-range performance, minimizing turbo vehicle “lag”, and an all new electronic spark control closed loop system that controls detonation through the use of spark retard. Revisions of basic engine components to ensure durability and pleaseability equivalent to that of a conventional engine are discussed. Further development of this powertrain concept may provide the flexibility to meet legislated fuel economy levels of the future without severe compromises in vehicle size or performance.

THE MATCHING CASE METHODOLOGY is a technique for assigning effectiveness values to existing restraint systems. The importance of the matching case methodology is that it utilizes field accident data exclusively - accidents in which a specific restraint was used are compared to accidents of similar injury potential but whose occupants did not use the restraint being evaluated. The resulting average injury values enable the researcher to calculate that restraint system's effectiveness across the various classifications of injury severity. Because the methodology does rely upon accident data, projections of restraint system effectiveness have the potential to come much closer to reality than would be the case if they were dependent primarily upon the theoretical application of laboratory results.

This paper presents a simplified concept of the cab-over-engine tractor ride problem. It discusses ways ride can be improved and the reasons cab suspension was chosen as the preferred solution. It describes the Ford CL-9000 cab suspension, explains why it improves ride and includes some data to indicate the benefits that are realized.

Belt systems are an appropriate means for realizing effective occupant protection. There are technical possibilities known, e.g. belt force limiters and preloading devices, which permit extreme safety requirements to be fulfilled by means of purposive coordination of the belt system to the structural deformation behaviour. The results presented here provide an example. It is at present difficult to evaluate the effectiveness of an occupant restraint system. One reason among others is the lack of an uniform complex Evaluation Index. In this paper, a suggestion is made concerning this problem: Introduction of the Evaluation Index EI.