On Local Nonquadratic Tracking Control for Continuous-time T-S Fuzzy Systems

This paper is concerned with the tracking control problem for continuous-time nonlinear systems that are represented by the Takagi-Sugeno (T-S) fuzzy models. Attention is focused on the design of a tracking controller attenuating the tracking error as small as possible in the H infinity performance sense. In order to derive less conservative results, conditions for designing tracking controller are established based on a relaxed approach in which nonquadratic Lyapunov function are used. The well known problem of handing time-derivatives of membership functions (MFs) is overcomed by reducing global goals to the estimation of region of attraction. It is shown that conditions for the solvability of the tracking controller design given here are written in the form of linear matrix inequality (LMI) which can be efficiently solved by convex optimization techniques. Simulation example is given to demonstrate the validity of the proposed approach.