Inverse-NARMA: a robust control method applied to SI engine idle-speed regulation

This paper presents a control technique based on a directly identified non-linear inverse of a stable system. A NARMA model of the inverse of the uncontrolled system is identified using reversed input-output data collected experimentally from the plant. Linear identification is carried out on the plant which is pre-compensated by the identified inverse, sufficiently time delayed to be causal. This achieves a reduction in the uncertainty representation necessary to model the non-linearity. Subsequent robust linear controller design results in an improvement in robust performance when using the inverse pre-compensator. The method is applied to the automotive SI engine idle-speed control problem using a parameter space linear robust control design technique. The result is experimentally validated using. an electric dynamometer. (C) 2002 Elsevier Science Ltd. All rights reserved.