A Less Conservative Iterative LMI approach for Output Feedback Controller Synthesis for Saturated Discrete-Time Linear Systems

This paper deals with the design of output feedback for multivariable (MIMO) linear discrete-time systems subject to actuator saturation. The saturation is included in a convex hull and a saturation-dependent Lyapunov function is used to ensure stability of the closed-loop. The guaranteed domain of attraction is enlarged by an iterative algorithm using linear matrix inequalities (LMIs). In numerical examples, the new approach is compared to the state of the art methods. Therefore, quadratic and saturation-dependent Lyapunov functions are used. It is shown that the new approach leads to less conservative results in both cases. Even with quadratic Lyapunov functions, the new approach provides less conservative results than existing methods with saturation-dependent Lyapunov functions.