Linear robust control of identified state-space non-linear inverse compensated SI engine

This paper presents a non-linear inverse compensation methodology based on a technique similar to Horowitz's non-linear quantitative feedback theory. A causal inverse is found based on an identified non-linear plant model. Linear identification of the non-linear identified inverse compensated system is carried out in order to achieve a reduction in the unstructured uncertainty representation. Subsequent robust control design results in an improvement in robust stability and robust performance over the uncompensated system. Using a parameter space linear robust control design technique, the method is applied to the automotive Spark ignition (SI) engine idle speed control problem and is experimentally validated using an electric dynamometer.