Abstract
This paper investigates the problem of decentralized piecewise H-infinity filtering design for a class of discrete-time large-scale nonlinear systems with time-varying delay. The considered large-scale system consists of a number of nonlinear subsystems, and each nonlinear subsystem is represented by a Takagi-Sugeno (T-S) model. The time-varying state delay of each subsystem is assumed to be of an interval-like type with lower and upper bounds. The objective is to design a decentralized piecewise filter such that the filtering error system is asymptotically stable with a guaranteed H-infinity disturbance attenuation level. A two-term approximation method is proposed to transform the filtering error system into an interconnected formulation, and the decentralized H-infinity filtering problem is reformulated in the context of input-output (JO) stability. Based on a piecewise Lyapunov-Krasovskii functional (PLKF) combined with the scaled small gain (SSG) theorem, less conservative results are presented for the decentralized piecewise H-infinity filtering design of the large-scale T-S fuzzy system in terms of linear matrix inequalities. Two examples are provided to illustrate the effectiveness of the proposed method. (C) 2015 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.