Precise Compensation for Positional Accuracy of Ultra-Precision Air-Bearing Motion Stage Based on the Self-Calibration Method

Abstract

In this paper, a high-efficiency self-calibration method was proposed, which was successfully applied to the ultra-precision air-bearing motion stage. Firstly, digital grating focusing, camera vision measurement and position synchronous output signal control were integrated, which can effectively improve the acquisition accuracy of stage positional data. Then, based on the least square algorithm the systematic error compensation value of motion stage can be quickly obtained through the fitting processing of three different measurement views. The experimental results showed that the proposed self-calibration measurement system can successfully realize ultra-precision air-bearing stage accurate location, and the orthogonality and shrinkage were controlled within 1 arcsec and 300\xa0nm, respectively. This compensation method can effectively avoid the problems of high cost and poor environmental anti-interference in the laser interferometer measurement system, and will have a broad application prospect in the fields of high-end lithography and ultra-precision machining.