Sensorless Acceleration Estimation and Acceleration Feedback Control to Improve the Disturbance Torque Rejection on Galvano Motor System

This paper proposes a high-performance disturbance rejection for the Galvano motor system through sensorless acceleration estimation and acceleration feedback control. The Galvano motor system is wildly used in the laser processing area because of its fast response and high accuracy. To meet the accuracy and response requirements, the Galvano motor is implemented by a permanent magnet (PM) motor with a sine/cosine encoder. Besides, a laser mirror is coupled with the motor for the motion control of the laser beam. Considering the application on high-speed laser drilling, the disturbance torque caused by the unbalanced mirror vibration will affect the drilling accuracy. To minimize the impact of undesired torque vibration, a separated observer is firstly proposed for the instantaneous acceleration estimation. Besides, the acceleration feedback control is proposed for the disturbance torque rejection. According to experimental results, the proposed sensorless acceleration estimation and control improve the disturbance rejection performance on a Galvano motor system.