Automotive Engine Control with Rational Function Satisfying inequality Constraint

The major drive of current engine development is to increase fuel economy. It has become very essential to manage the restriction due to the boundaries which divide the engine operation conditions into the normal and the abnormal ones such as knocking and misfiring because an optimal operation condition is often close to such a boundary. It indicates that required controls must satisfy inequality state constraints derived from identified boundaries. This paper describes a model following control satisfying the inequality state constraint of knocking with an explicit rational function which is easy to be implemented on production ECUs. The proposed control design was successfully applied to a simple engine model.