T–S region-based fuzzy control with multiple performance constraints

Takagi–Sugeno fuzzy control problems with minimizing H 2 / H ∞ norm are investigated in this paper. A redesigned T–S fuzzy model and controller are called a T–S Region-based Fuzzy Model (TSRFM) and a T–S Region-based Fuzzy Controller (TSRFC), respectively, which are derived from the fuzzy region concept and the robust control technique. The fuzzy region concept is used to divide the general plant rules into several fuzzy regions and the robust control technique is used to stabilize all plant rules of each fuzzy region. In this case, the stability conditions with H 2 / H ∞ performance are derived from Lyapunov criterion, which are expressed in terms of LMIs. For the fuzzy model involving large plant rules, the proposed idea greatly reduces the total number of LMIs and controller rules so that TSRFC is easy to implement with simple hardware. Although the controller rules are reduced, TSRFC is able to provide performance as good as former designs.