Iterative learning control design for Smith predictor

Abstract

The Smith predictor has been used to improve the closed-loop performance for systems with time delays. This paper proposes a frequency-domain method to design an iterative learning control to further improve the performance of Smith predictor controller. For a time-invariant plant with multiplicative perturbations and a Smith predictor controller, we derive a sufficient and necessary condition (which has the same form as that of a general robust performance design problem) for the iterative process to converge for all admissible plant uncertainties. In addition, the iterative learning controller under plant uncertainty is designed. An illustrative example demonstrating the main result is presented. © 2001 Elsevier Science B.V. All rights reserved.