Delay-dependent finite-time H∞ filtering for networked control systems: A switched system approach

This paper investigates the problem of finite-time H_∞ filtering for networked control systems (NCS) with time delay and packet loss simultaneously. Initially, a switching model is utilized to describe these network-induced imperfections, which can be denoted as three switching subsystems. Furthermore, in the case of packet dropout, the first-order holder (FOH) is constructed to make the controller use the previous state. A full-order filter is designed to estimate the output signal of the NCS. Based on the employed appropriate Lyapunov-Krasovskii functional and auxiliary slack matrices, sufficient conditions are derived in terms of linear matrix inequalities(LMIs), which can ensure the resulting filtering error dynamical system is bounded and satisfies a prescribed H_∞ disturbance attenuation in a fixed finite-time interval. Subsequently, a numerical example is exploited to demonstrate the applicability and validity of the proposed filter design method.