Machining, Measurement, and Control Laboratory

A Servo Parameter Tuning Method for High-speed NC Machine Tools based on Contouring Error Measurement
Kangkyu Lee (Kyoto University)
Soichi Ibaraki (Kyoto University)
Atsushi Matsubara (Kyoto University)
Yoshiaki Kakino (Kyoto University)
Yasuhiko Suzuki (Yamazaki Mazak Corp.)
Satoru Arai (NSK Ltd.)
Jan Braasch (Dr. Johannes Heidenhain GmbH)

In the latest high-speed and high-acceleration NC machine tools, the structural vibration is one of the most critical factors to deteriorate the machine's contour-ing performance. Particularly on such a machine, the parameters in a CNC servo control system must be carefully tuned, since too high response of the latest CNC units often causes severe structural vibration. This paper presents a practical servo tuning method for high-speed machine tools to optimize its contouring ac-curacies. In order to reduce the structural vibration with the minimum sacrifice of control bandwidth, the tuning is based on iterative measurement and simulation of the machine's contouring performance. A case study shows that a proper tun-ing of servo parameters significantly reduces the structural vibration and im-proves the machine's overall contouring accuracy.