Measurement and compensation of corner-tracking errors of CNC machine tools

In this paper, a newly developed system for measuring the corner-tracking errors of the axes of XY tables is reported. Several CNC machine tools were tested and current methods for improving tracking errors were evaluated by using the developed system. To deal with the corner-tracking problem, the inverse compensation strategy was introduced, and its effectiveness was investigated through computer simulation. Based on the principle of the inverse compensation, a new compensation technique making use of the measured error is proposed. Some experiments applying the proposed technique to a machining center were conducted and the effectiveness was confirmed. The proposed compensation technique is ease to apply to CNC machine tools and high-precision trajectories can be obtained without the necessity of precisely modeling the feed drive systems.