A Design Method for Smith Predictors for Minimum-Phase Time-Delay Plants

Abstract

In this paper, we examine a design method for a modified Smith predictor for minimum-phase timedelay plants. The modified Smith predictor is well known as an effective time-delay compensator for a plant with large time delays, and several papers on the modified Smith predictor have been published. However, the parameterization of all stabilizing modified Smith predictors has not been obtained. If this can be obtained, we can express existing proposals for modified Smith predictors in a uniform manner, and the modified Smith predictor can be designed systematically. The purpose of this paper is to propose the parameterization of all stabilizing modified Smith predictors for minimum-phase time-delay plants. The control characteristics of the control system using the parameterization of all stabilizing modified Smith predictors are also given. Finally, numerical examples for stable plants and unstable plants are illustrated to show the effectiveness of the proposed parameterization of all stabilizing modified Smith predictors.