Fuzzy robust tracking control for uncertain nonlinear systems

A robust output tracking control technique for nonlinear systems is developed. First, the Takagi and Sugeno (T-S) Fuzzy model with parametric uncertainties is employed to represent a nonlinear system. Based on (T-S) fuzzy model, fuzzy robust state feedback output tracking controller and fuzzy robust observer-based output tracking controller are proposed. Sufficient conditions are derived for robust asymptotic output tracking controllers in the format of linear matrix inequalities (LMIs), which can be very efficiently solved by using LMI optimization techniques. The effectiveness of the proposed fuzzy tracking controllers is finally demonstrated through numerical simulations on an inverted pendulum. (C) 2002 Elsevier Science Inc. All rights reserved.