Motion Control Techniques of Rotary Table for 5-axis Machining Centers

Abstract

This paper describes the motion control techniques of rotary tables for the 5-axis machining centers. In the 5-axis machining centers, various causes of inaccuracy exist in the rotary tables. In this study, the causes of inaccuracy are investigated. As the result, it is clarified that the main causes of inaccuracy: servo response, fluctuation of rotational velocity, backlash and the signal delay of rotary encoder. Motor torque saturation of the rotary axis also yields a problem. Based upon the investigated results, some compensators for the problems were proposed. It is clarified that the proposed compensators can much improve the synchronous accuracies.