Fault detection for networked systems with uncertain time-delay and packet dropout using delta operator

Abstract

This paper addresses the problem of observer-based fault detection for networked control systems (NCSs) with uncertain time-delays and data packet dropouts. The uncertain time-varying delays and packet dropouts of NCSs are modeled as parameter uncertainties of the NCSs and a stochastic variable satisfying Bernoulli distribution, respectively. Combining with the delta operator theory, a new discrete model is constructed to depict the behavior of the NCSs. Then, based on the established model, an observer-based H _∞ fault detection filter is proposed to guarantee the stability of the delta operator system and the sufficient conditions of the H _∞ performance for the filtering error system are derived with linear matrix inequalities (LMIs) and Lyapunov-Krasovskii functional technique. The parameters of the filter are solved via LMI toolbox. A simulation example is provided to illustrate the effectiveness of the proposed method.