| The Takagi-Sugeno (T-S) fuzzy system provides an alternative for system modeling by combining fuzzy reasoning and mathematical models. In this thesis, we consider the performance analysis and control design for T-S fuzzy systems. A systematic way is suggested to check the stability of T-S fuzzy systems. We then extend the consideration to the uncertainty case. The uncertainty can be nonlinear and (possibly fast) time-varying. A robust control scheme is proposed to render the uncertain T-S fuzzy system practically stable by utilizing the Lyapunov minimax approach. Only the possible bound of the uncertainty is needed. Two specific approaches, the threshold approach and the structural approach, are presented to deal with the mismatched case (i.e., the uncertainty that does not satisfy the matching condition). We also consider the control design for discrete-time T-S fuzzy systems for both matched and mismatched cases. To explore the applicability and effectiveness of this approach to nonlinear control problems, we apply this control design to a nonlinear missile autopilot problem. |
