Non-fragile control for interval type-2 TSK fuzzy logic control systems with time-delay

Abstract

The study is concerned with non-fragile controller design for nonlinear systems with time-delay which are described by the interval type-2 Takagi–Sugeno–Kang fuzzy logic control system. Interval type-2 Takagi–Sugeno–Kang fuzzy logic control systems have been used in many applications and shown better outperforms in some cases than their type-1 counterparts. In this paper, a Lyapunov–Krasovskii functional is constructed through the Wirtinger-based integral inequality which is less conservative than the Jensen inequality, then sufficient conditions are obtained to stabilize the interval type-2 Takagi–Sugeno–Kang fuzzy logic control system with time-delay. Two types of controllers are designed, one is normal and the other is non-fragile. Non-fragile controllers make their implementation easier allowing to tune controller parameters automatically. The results are established in the form of linear matrix inequalities, which can be easily solved by MATLAB toolbox, then the controller gain matrices can be developed. Simulation examples in different cases are provided to demonstrate the effectiveness of the proposed method.