Observer-based robust fuzzy control of nonlinear systems with parametric uncertainties

This paper addresses the robust fuzzy control problem for nonlinear systems in the presence of parametric uncertainties and the state variables unavailable for measurement. The Takagi-Sugeno (T-S) fuzzy model system with parametric uncertainties is adopted for modeling the nonlinear system and establishing fuzzy state observer. Sufficient conditions are derived for robust stabilization in the sense of Lyapunov asymptotic stability and are formulated in the format of linear matrix inequalities (LMIs). The effectiveness of the proposed fuzzy controller and fuzzy observer design methodology is finally demonstrated through numerical simulations on an inverted pendulum system. (C) 2002 Elsevier Science B.V. All rights reserved.