Robust observer-based H_∞ control for a class of networked control systems

This paper focuses on the problem of robust H_∞ controller design for networked control systems with the effects of time-varying random delay. The model of discrete-time networked control systems was obtained by discretizing the model of continuous-time ones. With the aid for an example, the influence of the delay on the dynamic performance of the discrete-time system was analyzed, which is less than a sampling period. Based on the discrete-time model of networked control system, by choosing a suitable Lyapunov functional and using linear matrix inequality (LMI) and cone complementarity linearization (CCL) algorithm, an observer-based controller was designed to guarantee the robust by asymptotical stability of the closed-loop system and achieve the prescribed H_∞ disturbance attenuation level. A numerical example proved the proposed method to be feasible.