Two-Dimensional Compensation Method for Positioning Error in Conventional X-Y tables

Abstract

A high positioning accuracy of feeding system is one of heavy component in precision machine systems, and its compensation method for positioning accuracy is also an important technique in feeding systems. The compensation method provides the prediction of positioning errors and correction of positioning accuracy in control systems. In this paper, a two-dimensional compensation method for XY feed system in CO2 laser machine will be introduced. First, positioning errors of XY tables are measured by a CCD image processing system, by using a standard specimen. Then the two-dimensional compensation function can be determined from the two-dimensional positioning errors curve of the XY feeding system-the system responsible for correcting the positioning error of the XY table. Finally, the position error of XY feeding system that used the method to correct its positioning errors is measured by a HP 5519A Interferometer, and verified that it effectively increased the positioning accuracy of XY table. According to the compensation experiments, the X-axis of the XY feeding system decreased from 7 microns to 2.8 microns and the Y-axis is from 17 microns to 2.6 microns. In addition, the compensation method does not decrease the perpendicular accuracy and the repeatability accuracy of XY feeding systems.

Keywords

• positioning error
• two-dimensional compensation method
• error compensation
• precision positioning system