Sliding Mode Control with Parameter Adaptation for a Class of Cable Feed System

To overcome the strong nonlinearity and big lag of a class of cable feed system and improve its robustness against wind disturbance, sliding mode control with parameter adaptation is proposed. Based on Lyapunov stability theory, a MIMO sliding mode control law is derived with the linear model of the plant. The modeling error and wind force are considered as external disturbances that are estimated and compensated on line with parameter adaptation. A series simulation is finished with the parameters of a 50 meter scaled model of Five hundred meter Aperture Spherical Telescope. The results show that the tracking error is reduced significantly and the robustness of system is improved with the proposed controller than that with traditional PID controller.