Adaptive guaranteed cost control for time-delay systems

The guaranteed cost control problem for time-delay systems is investigated. The main contribution in this paper is an adjustable parameter is introduced in the controller, which helps to improve the feedback gain and decrease the guaranteed cost. Furthermore, by designing the adaptive law of adjustable parameter and introducing it into the stability condition, the feedback gains changing with time are gotten. Compared with the results by fixed feedback gain, the proposed method leads to less conservatism. Simulation example is given to show the effectiveness of the proposed approach.