Acceleration Measurement-Based Disturbance Observer Control for a Belt-Drive Servo Instrumentation

An acceleration measurement-based disturbance observer (DOB) control method is proposed to capture and eliminate transient and dramatic dynamic disturbance torque in the flexible belt-drive servo instrumentation. The essence of this method is to incorporate the acceleration difference between the motor side and the load side to implement a DOB in the dual-rate control loop. The acceleration difference is sensitive to the rate variation caused by the motor-load large span distribution. The input signal of the motor inner loop with the high bandwidth is equivalently processed to obtain the estimated motor-side acceleration. However, the observed acceleration disturbance suffers from low-frequency drift and noise accumulation, resulting in system instability under integral characteristics. Therefore the H-8 principle is used to ensure stronger stability and the compensator is bandpass-corrected to enhance the anti-disturbance performance in a limited bandwidth. The proposed method is experimentally validated to effectively suppress the disturbance torque after obtaining an optimal trade-off between robust stability and anti-disturbance. The error spikes and buffeting in the flexible transmission chain are further reduced compared with the conventional methods.

Automated summary

In this paper, an acceleration measurement-based disturbance observer (DOB) control method is proposed to eliminate transient and dramatic dynamic disturbance torque in the flexible belt-drive servo instrumentation. The method incorporates the acceleration difference between the motor side and the load side in a dual-rate control loop. Experimental validation shows that the proposed method effectively suppresses disturbance torque and reduces error spikes and buffeting compared to conventional methods.