Improved Results on Robust H_∞ Control of Uncertain Discrete-time Systems with Time-varying Delay

In this paper, the robust H control problem for uncertain discrete-time systems with time-varying state delay is con- sidered Based on the Lyapunov functional method, and by resorting to the new technique for estimating the upper bound of the difference of the Lyapunov functional, a new less conservative sufficient condition for the existence of a robust H controller is obtained Moreover, the cone complementary linearisation procedure is employed to solve the nonconvex feasibility problem Finally, several numerical examples are presented to show the effectiveness and less conservativeness of the proposed method.