Single-frequency interference straightness error and its position measurement and compensation device and method

Abstract

The invention discloses a measuring-compensating device and method for a single-frequency interference linearity error and position thereof. After passing a half-wave plate, the polarization direction of a linearly polarized light beam output by a single-frequency laser is adjusted to 45 degree relative to the paper surface, the modulated linearly polarized light beam is split by a first depolarization splitting prism, a transmitted light beam enters a Wollaston prism type laser single-frequency interferometer, a reflected light beam enters a Michelson type laser single-frequency interferometer, the Wollaston prism type laser single-frequency interferometer serves as a sensing unit to process formed circularly polarized and linearly polarized interference signals, and a linearity error and a position thereof are measured. An error detection and compensation part uses the Michelson type laser single-frequency interferometer as a sensing unit, formed thickness-equivalent interference fringe images are analyzed, swing and pitch angles are measured, a measuring result of the linearity error and the position thereof is compensated according to the measured pitch angle, and the measuring precision of the linearity error and the position thereof is improved.

Description

technical field [0001] The invention relates to a measuring device and method characterized by adopting an optical method, in particular to a single-frequency interference straightness error and a device and method for measuring and compensating its position. Background technique [0002] Precision linear guides are key moving parts of precision manufacturing and measuring equipment such as computer numerical control machine tools and coordinate measuring machines. As the main performance indicators of precision linear guides, straightness combined with other degree of freedom parameters directly affect the precision of precision equipment. The demand for measuring instruments is also increasing. At present, the high-precision straightness measurement methods are mainly divided into laser alignment method, laser grating diffraction method and laser interferometry. Compared with straightness measurement methods such as laser alignment method and laser grating diffraction met...

AI Technical Summary

Problems solved by technology

However, since the measurement accuracy of the laser spot detection method is limited by the resolution of the position-sensitive detector or the four-quadrant detector, the measurement accuracy of the rotation angle of the measured object is low

In addition, although the laser heterodyne interferometer has a good ability to resist environmental interference, the periodic nonlinear error of the laser heterodyne interferometer is larger than that of the laser single-frequency interferometer, which limits the straightness and its position measurement. Increased accuracy

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