Robust H∞ filtering for a class of multiple time delays discrete-time systems with nonlinear inequalities constraints

A delay-independent approach to robust H_infin filtering is proposed for discrete-time system with multiple delays in the state and nonlinear inequality constraints. The uncertain parameters are supposed to reside in a polytope and a method for designing the robust H_infin filters for the filtering error system with sector nonlinearities is derived. The designed filters can guarantee robustly asymptotically stable and a prescribed H_infin noise attenuation level for the filtering error system. A unified framework of filter can be obtained from the solution of convex optimization problem via linear matrix inequality (LMI), which can be solved via efficient interior-point algorithm. Finally, an example is given to illustrate the effectiveness of the proposed methods.