Electronic Engine Control Systems for the Smaller Passenger Car

The usefulness of a micro-processor based engine vehicle control system has been demonstrated and widely recognized. With the rapid progress of LSI technology in process and structure, the improvement of micro-processor performance and reliability is remarkable in computing speed, functions, and memory size. By utilizing this improved micro-processor performance, a more sophisticated engine-vehicle control system can be composed. The objective of this study is to clarify the requirements for an engine control unit (ECU) and a control strategy in the case that these systems are applied to smaller engines and smaller vehicles and where high accuracy of control is needed.

An experimental control unit has been developed. Both transient and steady state compensation controls for fuel injection and ignition timing have been investigated. The requirements for conversion time of the analog to digital converter, the interpolation logic for crank angle signal, and the compensation circuitry have been clarified. The effectiveness of the compensation control, asynchronous fuel injection, and the adaptive control of air to fuel ratio have been demonstrated.