Suppression of Adverse Effects of Transmission Clearance in Brushless DC Motor Servo Systems by Switching Compensation*

In conventional servo system with transmission mechanisms, the transmission backlash seems to be an inevitable phenomenon in many applications. Excessive backlash can lead to relative motion between the servo motor and the load, resulting in response delays, instability, and oscillations, consequently causing a decline in the dynamic performance of the system. To mitigate the negative effects of transmission backlash, this paper proposes a model-based backstepping adaptive control algorithm and a switching compensation approach tailored to transmission backlash. A feed-forward control gap compensation method is suggested. Leveraging identified servo system parameter information, this method achieves compensation and suppression of the nonlinearity caused by backlash. The efficacy of the proposed method is verified through theoretical analysis and simulation experiments, which also guaranteed its capability to effectively enhance the tracking accuracy and stability of the servo system while suppressing undesirable phenomena caused by backlash.