Iterative learning control design for Smith predictor

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