Fault detection for networked systems with randomly occurring nonlinearities via switched system approach

This paper addresses the fault detection (FD) problem for networked systems with with randomly occurring nonlinearities and incomplete measurements, including transmission time delays, packet dropouts, and signal quantizations which are described by a new switched system model. We aim to design a mode-dependent fault detection filter (FDF) such that, for all external disturbances, incomplete measurements, and the randomly occurring nonlinearities, the error between the residual and weighted fault is made as small as possible. The addressed FD problem is then converted into an auxiliary H_∞ filtering problem of switched systems with time-varying delays. By applying Lyapunov-Krasovskii approach, a sufficient condition for the existence of the FDF is derived in terms of certain linear matrix inequalities (LMIs). When these LMIs are feasible, the explicit expression of the desired FDF can also be characterized. A numerical example is exploited to show the effectiveness of the results obtained.