Microprocessor Control of the Automobile Engine

This paper addresses the advantages and constraints associated with microprocessor control of the automotive engine. The advantages center around the power of the microprocessor to compute virtually any complex control law, and the ease with which it permits the development of new calibrations and new control laws. The constraints relate to the speed of computation and the fact that the digital concept provides input/output relationships in finite increments rather than as continuous functions. We examine here in some detail the functional power of a digital controller to manipulate these input/output relationships, whether in the form of closed-form mathematical expressions, polynomial-series approximations, or multi-dimensional tables for linear interpolation.