H ∞ robust fuzzy dynamic observer-based controller for uncertain Takagi–Sugeno fuzzy systems

Abstract

This study considers the problem of robust controller design for uncertain Takagi–Sugeno (T–S) fuzzy systems with H∞ performance through fuzzy dynamic observer (FDO). Dynamic observer is an alternative structure for classical observer which can be regarded as a general form of a usual observer and has additional degrees of freedom in the observer structure. In this study first the idea of dynamic observer in linear systems is extended to T–S fuzzy systems and it is shown that FDO can be used effectively for tackling the drawbacks of the existing methods of classical observer-based robust controller design. Strict linear matrix inequality (LMI) conditions are presented for designing robust H∞ observer-based controller even in the presence of uncertainties in system matrix, input and output matrices simultaneously by employing FDO. Finally, efficiency of the proposed design method is shown in simulation results.