Abstract:Based on ray vector and optical characteristics of the cube-corner prism, mathematical expressions of the laser interferential displacement measurement affected by attitude angle of cube-corner, straightness, cosine error and Abbe error are derived. RENISHAW XL80 laser interferometer is used to build the optical measurement path and corresponding verification experiments are carried out. The results show that the error of interferential displacement measurement produced by the attitude angle normally does not exceed 0.1um; When straightness freedom error of the cube-corner occurs, the central positon of the returned measurement beam will produce a translation which corresponds with the horizontal or vertical straightness direction, but geometric displacement measurement error will not be introduced. The relevance between the offset of returned measurement beam of the cube-corner prism and the cosine error is derived, the relevance between the Abbe error and the Abbe arm value as well as yaw of the cube-corner prism is also presented. The experiment of interferential displacement measurement indicates that the displacement measurement accuracy can be effectively enhanced through correcting the Abbe error. Results of the research establish an analytical error method based on the cube-corner for interferential displacement measurement, which also provide a basis for the error compensation of interferential displacement measurement.
