Output feedback robust H∞ control of uncertain fuzzy dynamic systems with time-varying delay

This paper presents an output feedback robust H^∞ control problem for a class of uncertain fuzzy dynamic systems with time-varying delayed state. The Takagi-Sugeno fuzzy model is employed to represent an uncertain nonlinear systems with time-varying delayed state. Using a single quadratic Lyapunov function, the globally exponential stability and disturbance attenuation of the closed-loop fuzzy control system are discussed. Sufficient conditions for the existence of robust H^∞ controllers are given in terms of matrix inequalities. Constructive algorithm for design of robust H ^∞ controller is also developed. The resulting controller is nonlinear and automatically tuned based on fuzzy operation