CONTROL OF TIME-DELAY SYSTEMS USING ROBUST FRACTIONAL-ORDER CONTROL AND ROBUST SMITH PREDICTOR BASED CONTROL

摘要

Many modifications have been proposed to improve the Smith predictor structure used to control plant with time-delay. Some of them have been proposed to enhance the robustness of Smith predictor based controllers. They are often based on the use of deliberately mismatched model of the plant and then the IMC method can be used to tune the controller. This paper compares the performance of two Smith predictor based controllers including a mismatched model to the performance provided by a fractional order Crone controller which is well known for managing well the robustness and performance tradeoff. It is shown that even if it can simplify the design of (robust) controller, the use of an improved Smith predictor is not necessary to obtain good performance.