Friction Compensation for High Precision Turntable Using Adaptive Sliding Mode Controller

To compensate for the dynamic friction effects in the high precision turntable system, a control scheme using adaptive sliding mode techniques is proposed. The friction force in the turntable system is characterized by the Lugre dynamic friction model. Both the system parameters and the dynamic friction parameters are assumed to be unknown, but each of them belongs to a known bounded region centered at its nominal value. The update laws and dual observers based on a smooth projection algorithm are developed to estimate the unknown parameters and the unmeasurable friction state. Furthermore, a sliding mode control term is incorporated to tackle the bounded disturbances and modeling uncertainties. The asymptotic stability of the closed loop system is shown via Lyapunov-based argument. Finally, simulation results validate the effectiveness of the proposed approach.