Robust controller design for uncertain systems with time delays: LMI approach

We present a robust output feedback controller design method for linear systems with norm-bounded time-varying parameter uncertainties and time-varying delays in both states and controls. And sufficient conditions for the existence of the robust output feedback controller of any order are given in terms of three linear matrix inequalities (LMIs). Furthermore, we provide a parameterization of all robust controllers from the positive-definite solutions of the LMIs.