Method for measuring straightness accuracy and position thereof based on double frequency interference principle

Abstract

The invention discloses a method for measuring straightness accuracy and positions thereof based on a double frequency interference principle. The measuring method adopts a double frequency optical laser to output laser beams containing cross-line polarized lights which are processed by the light splitting of a common spectroscope and a depolarization dispersion prism, the beam splitting of a Wollaston prism, the reflection of a right-angle prism, and the transmission of the Wollaston prism, the light splitting of a polarization splitting prism, the beat frequency of an analyzer to finally obtain a first-path reference signal and a second-path reference signal. The measuring method utilizes the dichroism and polarization property of optical devices to make up a double light path measurement structure based on the heterodyne interference principle; the simultaneous measurement of the straightness accuracy and the positions thereof is realized by measuring the optical path difference of the double path, thus having measuring accuracy of the nanometer straightness accuracy and the positions thereof. The method is mainly applied in the motion displacement measurement of an accurate work table, the straightness accuracy detection of an accurate guide rail and the like belonging to fields such as super-precision processing technology, micro-photo dynamoelectric systems, integrated circuit chip manufacturing technology, etc.

Description

technical field [0001] The invention relates to a measuring method characterized by adopting an optical method, in particular to a measuring method of straightness and its position based on the principle of double-frequency interference. Background technique [0002] Looking at the measurement methods of straightness at home and abroad, according to whether there is a straight line reference, the measurement methods of straightness can be roughly divided into two categories: the first type is the measurement method without a straight line reference, which mainly uses the error separation method, and according to the information acquisition There are different approaches. The non-linear benchmark measurement method can be divided into reverse method, dislocation method and multi-probe method. The error separation method is practical and reliable, and is suitable for online or offline measurement. Multiple measurement errors can be obtained in one measurement, but this method ...

AI Technical Summary

Problems solved by technology

Using the principle of laser heterodyne interference, it not only realizes the straightness measurement with nanometer precision, but also realizes the nanoscale displacement measurement of the measured straightness position, and solves the technical problem of simultaneous measurement of nanometer-level high-precision straightness and its position

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