Study on a New Method for Improving Resolution of Grating Interferometer Displacement Measuring System

Abstract

A method for improving resolution of grating interferometer displacement measuring system is developed in this paper. The measurement system consists of a grating interferometer and a phase-shift device. Two interference fringes are required in the detecting field of photoelectric sensor. If we change the signal phase of the interference fringe by moving the photoelectric sensor between the two interference fringes, the displacement equivalent converted from the photoelectric sensor will changed. The method is applied in positioning system and the experiments’ results indicate that the new displacement measuring method will improve the positioning accuracy about 33%. Also, the errors in the positioning process with the new method are discussed in briefly.

Keywords

• Grating interferometer
• phase shift
• displacement