An improved Η∞ approach for networked control systems with transmission delays and packet dropout

This paper is concerned with the H_∞ controller design for robust stabilization of networked control systems with the network-induced delay, data packet dropout and norm-bounded parameter uncertainties. In order to obtain less conservative results, a new augmented Lyapunov-Krasovskii functional is used and novel free-weighting matrices are employed to make some extra degree of freedom in the H_∞ design conditions. The feedback gain of a memoryless controller, maximum allowable delay bound and minimum disturbance attenuation level can be derived by solving a set of linear matrix inequalities (LMIs). The advantages of the proposed method are demonstrated by numerical example.