Robust Adaptive Type-2 Fuzzy Sliding Mode Control for Non-Linear uncertain SISO systems

Abstract

This paper deals with the synthesis of adaptive type-2 fuzzy logic controller for a class of single-input single-output system. Due to its ability in serving in universal approximation, the type-2 fuzzy logic system is used to approximate the unknown system dynamics, which will be adjusted according to the on-line adaptation laws deduced from the stability analysis. To ensure the closed loop system robustness, a modified sliding mode control signal is used. In this work, variable sliding surface is replaced by type-2 fuzzy logic system in order to reduce the starting energy without deteriorating the tracking performances. Furthermore, the knowledge of the upper bounds of the external disturbances and also the approximation errors is not needed. The global stability of the closed loop system is guaranteed in the sense of Lyapunov. As well, all signals involved are uniformly bounded. Finally, experiment results are presented to show the performance of the developed approach.