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This paper presents an original procedure for misfire detection in a high-performance 12-cylinder engine, based on the analysis of the time periods between subsequent combustions. A detailed analysis of the misfire effects on the engine crank-shaft instantaneous speed is presented, then a misfire detection procedure is designed, based on the misfire pattern recognition. The capability of this methodology was then validated under the worst case condition of a random misfire in several tests performed with the vehicle running on a circular race-track, at low and high load, in different gear, under acceleration and during a normal urban cycle. The results obtained are very interesting because the misfire pattern recognition works well even during cut-off or gear shifts, avoiding false alarm due to the strong influence that these phenomena have on crank-shaft dynamics.

The intent of this research is to understand the effects worn dampers have on vehicle stability and safety through dynamic model simulation. Dampers, an integral component of a vehicle's suspension system, play an important role in isolating road disturbances from the driver by controlling the motions of the sprung and unsprung masses. This paper will show that a decrease in damping leads to excessive body motions and a potentially unstable vehicle. The concept of poor damping affecting vehicle stability is well established through linear models. The next step is to extend this concept for non-linear models. This is accomplished through creating a vehicle simulation model and executing several driving maneuvers with various damper characteristics. The damper models used in this study are based on splines representing peak force versus velocity relationships.

This paper introduces a high accuracy method of measuring crankshaft angular position of an I-C engine. The method uses a sensor which couples magnetically to the starter ring gear. There are many automotive applications of this measurement of crankshaft angular position including ignition timing reference, engine performance measurement and certain diagnostic functions. The present paper disusses only the ignition timing application. Engine performance measurements are reported in refs. (1,2,3). The diagnostic application is discussed in refs. (4-5). The passage of a starter ring gear tooth past the sensor axis causes a pulse to be generated in the sensor output. The waveform of this sensor voltage is independent of engine angular speed (including zero speed). However, this waveform is a function of gear tooth profile and is consequently influenced by gear wear. The present method uses a finite state machine to process the sensor output signal.