Indirect Adaptive Fuzzy Sliding Mode Control for an Electrohydraulic Servo Mechanism

In this paper, a novel indirect adaptive fuzzy tracking control scheme is used for an electro-hydraulic servo mechanism. Since the dynamics of the system are highly nonlinear and have large uncertainties in modeling due to big changes in load and parameters, Adaptive Sliding Mode Controller (ASMC) is applied to the system. The proposed approach employs a fuzzy system to approximate the unknown nonlinear functions in designing the controller and error signal is generated for the adaptive law. Indeed by using the Lyapunov synthesis approach, an Indirect Adaptive Fuzzy Sliding-Mode Control (IAFSMC) is applied. In this approach both the equivalent control and switching-type control term in the sliding mode control law are approximated. Indirect Adaptive Fuzzy Sliding-Mode Control give the chance to control the system by less information of the parameters of the system. In addition effect of external disturbance due to friction is studied. Simulation results illustrate the design procedures and demonstrate the good tracking performance of the proposed controller