A Computerized On-Line Approach to Calculating Optimum Engine Calibrations

A current design objective of the automotive engineer is to calibrate the passenger car spark ignited engine for best fuel economy for a given level of exhaust emission performance. The need to achieve the best possible calibrations has motivated the application of mathematical optimization techniques to this problem. This paper describes a new on-line technique in which an engine dynamometer minicomputer, programmed with an optimization algorithm, automatically determines the optimum calibrations for spark advance, air-fuel ratio, and exhaust gas recirculation at fixed speed-load operating points. These points are selected by analysis of measured or simulated performance of the engine in a specified vehicle.