Guaranteed cost control for uncertain nonlinear systems with mixed time-delays: The discrete-time case

In this paper, the guaranteed cost control problem is investigated for a general class of discrete-time uncertain nonlinear systems with mixed time-delays. The mixed time-delays under consideration comprise both the discrete and the distributed delays. By using the completing-the-square technique, the discrete and distributed time-delays are handled in a unified framework. Then, by constructing an appropriate Lyapunov functional, a sufficient condition is established under which the closed-loop control system is stable and an adequate performance index is guaranteed over all admissible uncertainties as well as mixed time-delays. Based on the sufficient condition, the nonlinear cost-guaranteed controller is designed and an explicit expression of the controller parameter is obtained. Finally, a numerical simulation example is presented to demonstrate the effectiveness and applicability of the results derived.