High Performance Motion Control of Rotary Table for 5-Axis Machining Centers
Ryuta Sato and Masaomi Tsutsumi
Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology
2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
Received:August 28, 2007Accepted:September 1, 2007Published:November 5, 2007
Keywords:5-axis machining center, rotary table, motion control, worm gear, synchronous accuracy
We discuss motion control techniques of rotary tables for 5-axis machining centers. Three translational axes and two rotary ones are controlled simultaneously in the machining of complex shapes such as impellers. A tilting rotary table powered by a worm gear is generally used as the rotary axes for 5-axis machining centers, and various causes of inaccuracy exist in the rotary axes. In this study, we clarified three causes of inaccuracy exists in the rotary axis: rotational fluctuation in the worm gear, backlash, and measurement delay of rotary encoder for feedback. Motor torque saturation of the rotary axis also causes a problem when rotational velocity is changed rapidly. Based upon investigated results, we propose compensators for improving synchronous accuracy. We avoid torque saturation in the rotary axis through acceleration-deceleration design. To verify the effectiveness of the proposed compensators, we applied them to an experimental set-up including a rotary axis. As the results of experiments, it is clarified that the proposed compensators improve the synchronous accuracy of translational and rotary axes.
Cite this article as:R. Sato and M. Tsutsumi, “High Performance Motion Control of Rotary Table for 5-Axis Machining Centers,” Int. J. Automation Technol., Vol.1 No.2, pp. 113-119, 2007.Data files: