H∞ state-feedback control for fuzzy systems with input saturation via fuzzy weighting-dependent Lyapunov functions

This paper proposes a method for designing an H-infinity state-feedback fuzzy controller for discrete-time Takagi-Sugeno (T-S) fuzzy systems with input saturation. To address the input saturation problem, this paper first formulates a set invariance condition for the T-S fuzzy systems, Then, based on the set invariance condition, this paper establishes H-infinity stabilization conditions associated with a fuzzy weighting-dependent Lyapunov function, where the fuzzy controller is designed to be dependent on not only the current-time but also the one-step-past information on the time-varying fuzzy weighting functions. In the derivation, the H-infinity stabilization conditions are first formulated in terms of parameterized linear matrix inequalities (PLMIs), and then reconverted into LMIs by an efficient relaxation technique. (C) 2008 Elsevier Ltd. All rights reserved.