Abstract
In this article, the dynamic output-feedback H infinity control problem is investigated for discrete-time state-delay systems subject to exogenous disturbances and actuator saturations under the round-robin communication protocol. Using the switched system approach, the Lyapunov-Krasovskii functional and the modified sector condition, sufficient conditions are first obtained under which the closed-loop systems can achieve some desirable performance indices such as the boundedness, the H infinity performance and the stability in the absence of disturbances. Then, the controller is explicitly characterized by means of the solvability of linear matrix inequalities. For the case without time delays, the corresponding conditions are also presented. Subsequently, the optimization problems about the performance indices are discussed. Finally, the benefit and effectiveness of the proposed results are specifically illustrated via two simulation examples.