Precision control and compensation of machine tools and servomotor via disturbance observer

• Main Authors: KANG Qi, LIN Jun
• Format: Article
• Language: English
• Published: Academic Journals Center of Shanghai Normal University 2012-10-01
• Series: Journal of Shanghai Normal University (Natural Sciences)
• Subjects: CNC; servomotor; statespace disturbance observer; autotuning
• Online Access: http://qktg.shnu.edu.cn/zrb/shsfqkszrb/ch/reader/create_pdf.aspx?file_no=201205006&year_id=2012&quarter_id=5&falg=1

The computerized numerically-controlled machine tool CNC is a highly integrated mechatronic system in manufacturing. However, uncertainties degrade its motion accuracy. In order to estimate the uncertainties of the parameter variation and current measurement , in this paper, a state-space disturbance observer is successfully applied to servomotors in the velocity and the current loops. Via the modeling of CNC machine tool and servo motor, the parameters affecting the accuracy are continuously variated and an auto tuning procedure is applied to identify the varied parameters of the motor. The experimental results show that the influences on the velocity and current caused by the linear errors ,external disturbance and etc have improved significantly, and eventually the effect of suppressing the torque ripple is achieved .