Low-Speed Disturbance Suppression Strategy of Direct Drive Servo Motor Based on Combination of Sliding Mode Control and Disturbance Compensation

The precision and stability of direct drive servo motor speed regulation system are seriously affected by complex disturbance like cogging effect and load variation at low speed. This paper studies a low-speed disturbance suppression method for direct-drive servo motors on the basis of sliding mode control and the compensation for disturbances. By introducing the reduced order disturbance observer into the sliding mode control for disturbance compensation, the chattering can be significantly reduced, the time-varying disturbance can be effectively suppressed, and the anti-interference ability of the system can be improved. The simulation results show that the control method proposed can effectively suppress the influence of various disturbances of the motor at low speed.