Controller design for delta operator time-delay systems subject to actuator saturation

In this paper, the problem of controller design is studied for a class of delta operator systems subject actuator saturation and time-varying state delay. Our main attention is to approximate the time-varying delay by using the three term approximation method. On the basis of the scaled small gain (SSG) theorem, input-output (IO) approach, Lyapunov-Krasovskii functional and Wirtinger-based inequality, a new set of sufficient conditions in terms of linear matrix inequalities is obtained to not only ensure the existence of the desired state feedback control law, but also cover the issues of actuator saturation and performance constraints. Finally, the advantages and the feasibility of the proposed method are demonstrated by the numerical examples.