Robust H_∞ filtering for a class of uncertain networked control systems with limited communication

Based on combining switched Lyapunov function and parameter dependent Lyapunov function, a robust H_∞ filter with structure switched according to the system model changes was designed for networked control systems with limited bandwidth and polytypic uncertainties. A new improved performance criterion for the existence of robust H_∞ filter was presented by introducing two slack matrices which made a kind separation between the system matrices and the positive definite Lyapunov matrices. A filter was directly derived from this criterion which can guarantee not only quadratic stability of the closed-loop systems but also the H_∞ norm bound within a predefined level. As a result, the vertex-dependent Lyapunov function can be adopted to deliver a less conservative result. A numerical example was used to illustrate the effect of the proposed approach.