Nonlinear M.I.S.O. direct-inverse compensation for robust performance speed control of an S.I. engine

Abstract

Nonlinear inverse compensation is developed for an SI engine MISO system from an identified plant model. The proposed application of the inverse is similar to the use of inverse SISO systems in one of Horowitz’s nonlinear QFT methods. For robust control the nonlinearity is characterised as an unstructured uncertainty. The objective of the inverse system is linearisation to reduce the size of the uncertainty necessary to account for the system nonlinearity. An increase in achievable robust performance with any linear robust performance control design technique may then be obtained. The novel feature of the MISO strategies proposed is that they provide additional design control over the control efforts. The method is experimentally validated by application to the automotive SI engine idle speed control problem using an electric dynamometer.