Mixed H_/H<SUB align="right">∞ fault detection observer design for networked control system with variable sampling period

Abstract

For networked control system (NCS) with time-varying sampling period and time-delay, a discrete-time model with parameter uncertainties lying inside a polytopic framework is proposed. Based on the finite frequency parameter dependent quadratic H∞ index performance for minimising the disturbance and the corresponding H– index performance for maximising the worst-case fault sensitivity, a fault detection observer is designed for residual generation. By the aid of the generalised Kalman-Yakubovich-Popov (GKYP) lemma, the existence conditions of such an observer are given in terms of linear matrix inequalities (LMIs). A numerical example is given to illustrate the effectiveness of the proposed approach.