Robust H∞-tracking control design for T-S fuzzy systems with partly immeasurable premise variables

This study is concerned with the problem of robust H∞-tracking control design for T-S fuzzy systems with partly immeasurable premise variables and external disturbances. A novel fuzzy observer is constructed by using the measurable premise variables and the estimations of immeasurable premise variables of fuzzy models. And a new fuzzy control scheme is proposed by using measurable premise variables of fuzzy models as the premise variables of fuzzy controllers. Further, by constructing the set-theoretic description of fuzzy models, employing the Lipschitz-like conditions and adopting the set theory, new robust stability conditions are obtained. Compared with the existing results, the new approach can make better use of the measurable premise variables, which might achieve less conservative results. An example is given to illustrate the effectiveness of the proposed method.