Measurement of Straight Motion Accuracy Using the Improved Sequential Three-Point Method

The purpose of the paper is to realize precise measurement of straight motion accuracy over long travel. The reversal method as well as the sequential three-point method is conventional. However, it is difficult to measure motion accuracy over long travel precisely using either method. The paper proposes a new precise measuring method which will be called the improved sequential three-point method. In this method, the principles of the reversal method and the sequential three-point method are introduced. Straight motion accuracy of a slide table was measured over 850mm travel using the improved sequential three-point method. The standard deviations from 12times measurements were 1.0μm in horizontal position and 2.0arc sec in yaw angle.