Chattering-free sliding mode control for strict-feedback nonlinear systems using back-stepping technique

This paper proposes a fuzzy gain scheduling backstepping sliding mode control (FGS-BSMC) approach for a class of uncertain strict-feedback nonlinear system. First, system description and problem formulation is given. Second, the FGS-BSMC is proposed to design the controller for the strict-feedback nonlinear system. A sliding mode control (SMC) is employed to construct the backstepping sliding mode control (BSMC) approach for design flexibility of backstepping control and robustness of SMC. In order to decrease chattering result from SMC, a fuzzy logic system (FLS) is designed to construct the FGS-SMC, in which the gain of sign function can be scheduled adaptively according to the fuzzy rules. Finally, a verification example is given to demonstrate the effectiveness the proposed FGS-BSMC. Simulation results illustrate that the FGS-BSMC decreases chattering effectively and has better control performance against BSMC.