Design of a miniature grating displacement sensor with large range

Abstract

Compared with laser interferometer, grating displacement sensor has the advantages of small size, low cost, and strong environmental robustness. In this paper, a grating displacement sensor was proposed. The theoretical model of the grating displacement sensor was established using the optical effect of Doppler shift and linearly polarized light interference. Based on this model, the error of the grating constant and the displacement of grating during measurement were analyzed to achieve the measurement accuracy of the grating displacement sensor. The analysis result showed that when the error of grating constant or the displacement of grating increases, the measurement accuracy will decrease. By changing the error of grating constant or the displacement of grating, 42 sets of measurement accuracy were calculated. The analysis result will provide an important reference for the development of nanometer accuracy grating displacement sensors.