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The use of signature analysis to determine the acceptability of parts in a production line quality control situation is highly desirable. Specifically, the use of acoustic signature analysis is attractive due to the relaxed constraints in terms of fixturing the part in preparation for analysis. This study discusses techniques presently being investigated which rely on knowledge of the modal coefficients to direct the area of investigation.

A torque converter lock-up clutch was introduced by Chrysler Corporation in a majority of its passenger cars in the 1978 model year. The lock-up clutch improves fuel economy by eliminating torque converter slip in direct gear above a predetermined speed. The clutch and its controls were designed to fit within the confines of the existing transmission. The development of the clutch was primarily concerned with achieving adequate endurance life, good shift quality and isolation of torsional vibrations.

This paper presents the theory and hardware to simulate non-loglinear spectra (the typical field case), including a unique method of eliminating low amplitude reversals so that any service load history of high cycle fatigue can be simulated in a laboratory fatigue test. The feasibility of the proposed quasi-stationary random process to simulate the three standard SAE load histories on a statistical basis is demonstrated on both the theoretical and experimental basis.

The basis of block load fatigue testing is the cycle counting method used to produce the test programme. The poor correlation with random loading often found may be due to the traditional counting methods. The paper discusses the new and more physically realistic “rain flow” counting method and presents test results which show that it can be used to give a more accurate simulation of random load fatigue damage than three traditional counting methods. The techniques advocated are particularly applicable to industrial fatigue testing where simple digital computing facilities are available.

One of the more objectionable aspects of the use of diesel engines has been the emission of particulate matter. A literature review of combustion flames, theoretical calculations and dilution tunnel experiments have been performed to elucidate the chemical and physical processes involved in the formation of diesel particulate matter. A comparative dilution tunnel study of diluted and undiluted total particulate data provided evidence supporting calculations that indicate hydro-carbon condensation should occur in the tunnel at low exhaust temperatures. The sample collection system for the measurement of total particulate matter and soluble sulfate in particulate matter on the EPA 13 mode cycle is presented. A method to correct for hydrocarbon interferences in the EPA barium chloranilate method for the determination of sulfate in particulate matter is discussed.

A cooperative test program was conducted by the CRC-APRAC CAPI-1-64 Composition of Diesel Exhaust Program Group to evaluate the technical aspects of a proposed EPA recommended Heavy Duty Diesel Emission Measurement and Test Procedure. The proposed changes affected the sampling configurations and the types of instruments used. Six participants studied the effects of a number of variables on the proposed changes and evaluated some alternative systems that included both CHEMI and NDIR instruments. The tests were conducted at one site using a multi-cylinder engine operating on the 13-Mode Cycle. Equivalency of systems was demonstrated and the best performance was obtained with a special NDIR system.

This paper describes the application of a novel combustion chamber of re-entrant form to a high speed direct injection diesel engine. A parametric study with the major dimensions of the chamber as variables shows the relationship between oxides of nitrogen, specific fuel consumption and smoke emission. Control of pollutants is demonstrated at retarded injection timings without significant deterioration in performance. The major factors affecting hydrocarbon emission are presented and the combustion system is shown to comply with the most stringent exhaust emission legislation yet proposed.

This paper discusses the use of Extreme Value Analysis Technique for determining vehicle extreme service loads in service. A statistical method is presented (1) to estimate long term most severe loads in service from short term measurements, and (2) to estimate the multiple circuit proving ground loads from a few measured circuits. A procedure is also discussed for determining the minimum required trip time for recording load data (short term) so that the data have a statistically valid base for long term projection. Actual strain/time histories were measured for several structural components in “service-run-like” environment. Two thousand kilometers of run were recorded, the data were analyzed and the results presented. A detailed theoretical discussion on the extreme value distribution function is given in the Appendix.

A liquid chromatographic analysis system, a replica of the Arthur D. Little system, is described. This system may be used to make exhaust measurements in an engineering environment provided care is taken in the preparation of the analytical materials. The system was used to investigate the odorant formation processes in a small, direct injection diesel engine. The major factors influencing odorant formation were found to be the amount of fuel dispersion during the ignition delay and the nozzle uncontrolled fuel volume. These principles were embodied in a low exhaust odour engine and its performance is contrasted with an alternative combustion system.

This paper describes a study of the exhaust aerosols produced by a single cylinder Onan diesel engine using a rapid dilution sampling system. Diluted exhaust aerosols were analyzed with an electrical aerosol analyzer (EAA) and a transmission electron microscope. Mass concentrations of particulate matter were determined by gravimetric filter analysis. Volume mean diameters observed with the EAA were about 0.1 μm. Mass concentration measurements made with filters were in qualitative agreement with those calculated from the aerosol volume concentrations measured with the EAA.

The techniques used to characterize the chemical and physical nature of particulates in diesel exhaust emissions are reviewed. The emphasis is on understanding the broader aspects of the fundamental nature of not only diesel particulates, but particulate systems in general. Consideration is given to the special nature of particulates which make them significant pollutants and to the relative place of the diesel in the formation of man-made particles. The underlying combustion processes leading to carbon and sulfur based particulates are reviewed. The important variables in steps of the combustion processes which lead to particulate formation are considered, as well as major fuel and engine factors. Collection methods are examined with examples given from current diesel dilution techniques. Probes, sampling lines, and instrumentation are considered.

Particle size distributions have been measured in the exhaust of a single cylinder Onan diesel engine using an electrical aerosol analyzer. These measurements give volume mean diameter for the exhaust particles of about 0.1 μm. Other investigators have shown that the particles found in diesel exhaust consist of agglomerates of very small primary particles (about 0.025 μm diameter) and may contain condensed hydrocarbons. A mathematical model has been constructed to determine the particle size distributions which will result from the growth of the primary particles by coagulation. The coagulation equation was solved numerically for an expanding stratified system. The model indicates that the inhomogeneity characteristic of stratified combustion can explain the rapid growth of the primary particles into the larger particles observed in diesel exhaust.

This paper describes a microprocessor engine controller designed for onboard control of closed-loop fuel injection, spark advance, and exhaust-gas recirculation. Developed through the preproduction prototype stage, the controller utilizes software subroutines to accomplish such operations as multiplication and interpolation. Ignition is controlled by means of time delays from relatively widely spaced crankshaft-position pulses. Emissions, driveability, fuel-economy, and hardware-cost comparisons are made between the microprocessor engine controller and a 1977 production analog electronic-fuel-injection controller with a mechanical-advance-controlled distributor. Directions for future development efforts are also described.

The design of a microcomputer-controlled automotive AM/FM radio is discussed. The system features, and gives priorty to, a clock display. However, the 3-1/2-digit LED display can also serve as a 4-year calendar, elapsed-time counter, or frequency channel, on request. The tuning process automatically activates the frequency display. Basic aspects of real-time clocks and frequency measurements in microcomputer systems are discussed, as is the ability of the COSMAC processor to permit a software-generated clock to be obtained with low cost and high accuracy. While the ignition switch turns the display on or off, the CPU and clock run continuously. The use of CMOS circuitry in the system keeps the power drain below 5 milliamperes and assures months of system operation, even when the vehicle (battery) is not used.

Electronics suitable for engine control applications has steadily evolved from analog control systems to microprocessor based designs. The change in technology required in switching from analog to microprocessors has required sensor development, new analog to digital conversion techniques, and development of custom input/output circuits suitable for automotive applications. By proper design of the microcomputer system, an engine control unit can be developed that is cost effective compared to conventional analog circuit techniques while providing additional flexibility. The primary limitation of a digital approach is the long lead time required to change the ROM pattern. This lead time can be reduced by combining PROM and ROM in the same system.

Some methods are suggested for organizing simple automotive sensor and actuator elements to minimize wires and use the analytical capability of the program of instructions stored within the memory of the electronic controller to extract information or manipulate the actuators. An information exchange system between microcomputer control units is described which allows trading of information. In this way, no sensors need be duplicated and each microcomputer serves as a single concentrator which permits sending a large group of facts from one part of the vehicle to another using only a few wires.

The 1978 model year marks a turning point in the introduction of electronic controls in automobiles. Although most of the existing functions are performed with analog circuitry, microprocessors are beginning to come into their own. Their ability to respond to the challenge rests largely on communications. Establishment of standards for timing, inter-connection and protocol are a necessary but not sufficient condition for the orderly development of compatible support products employing different technologies. This paper discusses some techniques for avoiding communication bottlenecks and introduces the concept of semi-smart peripherals. Cited examples include spark control, A - D conversion and display control.

The development and evaluation of a sampling system and analytical technique for the measurement of PNA in diesel exhaust are described. The sampling system for steady state engine operation utilizes the dilution of exhaust gas with air, injection of 14C radioactive tracers and collection of the condensed particulates on a filter. An analytical procedure was developed which consists of extraction of the filter sample, separation of certain PNA by procedures including TLC and HPLC and measurement by ultraviolet spectrophotometry. BaP and BaA emissions were determined for one diesel engine at idle, half load and full load.

Five conclusions are drawn and discussed concerning single chip microcomputer trends and their impact on automotive systems. The conclusion's relate to: high performance microcomputers minimum cost microcomputers special purpose microcomputers decentralization of automotive systems use of EPROM in production systems

The development of Ford Motor Company's microprocessor based electronic engine control has identified a number of fundamental issues and general observations regarding the application of microprocessors to the automotive environment in the areas of microprocessor selection, cost partitioning and design objectives.