Improvement of Atmospheric Compensator to Reduce the Laser Measurement Error for Ultra-Precision Machine Tools

Abstract

Atmospheric compensator to reduce the laser measurement error caused by change in the refractive index of air has been produced and applied to the ultra–precision machine tool, and the position measurement error of the machine tool is actually reduced. In this study, the initial length which corresponds to deadpath length in optical path of the laser interferometer is treated to improve the performance of the compensator. The influence of the difference between the set value of initial length and the true one on measurement error is evaluated. The positioning accuracy of the machine tool has been improved by introducing the optimal value of initial length estimated by experimental results to the compensator.