Second-Order Sliding Fuzzy Interval Type-2 Control for an Uncertain System With Real Application

A new second-order sliding-mode type-2 fuzzy controller for nonlinear uncertain perturbed systems is developed in this paper. To overcome the constraint on the knowledge of the system-model, we have used local models that are related to some operating points to synthesize a type-2 nominal fuzzy global model. The control is based on the super-twisting algorithm, which is among second-order sliding-mode controls (SMCs). Moreover, two adaptive fuzzy type-2 systems have been introduced to generate the two super-twisting signals to avoid both the chattering and the constraint on the knowledge of disturbances and uncertainties upper bounds. These adaptive fuzzy type-2 systems are adjusted online by two adaptation laws that are deduced from the stability analysis in the Lyapunov sense. It has only one input, i.e., the sliding surface, and one output, i.e., the optimal values of the gains control, which are hard to compute with the original algorithm. Many results of the one-link manipulator are obtained: first by the simulation in order to compare the performances of the proposed method with that given by Levant and then in a real-time application in order to confirm the efficiency of the proposed approach. The experimentation and simulation are done for the tracking control problem.