Optimization of Engine Controls Using Geometric Programming

This paper deals with the development of a procedure to optimize engine fuel economy as a function of air-fuel ratio, spark advance, exhaust gas recirculation and air flow rate. The geometric programming method is used to determine optimum engine control settings when the solution is restricted by exhaust emissions or driveability constraints. This method is especially effective in fuel economy problems, where the constraints are highly non-linear. Some example problems are presented to demonstrate the efficiency of the procedure.