Robustness design of nonlinear systems: fuzzy Lyapunov approach

This study addresses a fuzzy Lyapunov method for the stability analysis of time-delay fuzzy systems subject to external disturbances. The Takagi-Sugeno (T-S) fuzzy model and parallel distributed compensation (PDC) scheme are first employed to design a nonlinear fuzzy controller in order to stabilize the time-delay fuzzy systems. According to the controlled system, the H infinity criterion is derived based on the fuzzy Lyapunov method, which is defined in terms of fuzzy blending quadratic Lyapunov functions. Based on the stability criterion, the time-delay fuzzy systems are guaranteed to be stable.