Roll angle measuring device and method based on diffraction grating displacement

Abstract

The invention discloses a roll angle measuring device and method based on diffraction grating displacement. The device comprises a dual-frequency laser, a 5% reflecting mirror, a polarization splitting prism, a diffraction grating, a first reflector and a second reflector. The diffraction grating is fixed on a to-be-measured object. The first reflector and the second reflector, serving as sensitive parts, are fixed through a first fixing support and a second fixing support to guarantee relative rest of the diffraction grating. The diffraction grating, the first reflector and the second reflector form an integral target reflector. The dual-frequency laser, the 5% reflecting mirror, a first analyzer, a second analyzer, a third analyzer, a first photoelectric receiver, a second photoelectric receiver, a third photoelectric receiver, the polarization splitting prism, a first 50% reflecting mirror, a second 50% reflecting mirror, a third 50% reflecting mirror and a high-reflecting light mirror form a measuring head. The device which is based on laser heterodyne interference, diffraction grating displacement and spatial layout is capable of realizing roll angle measuring, high in precision and high in anti-interference capability, and actual application is facilitated.

Description

technical field [0001] The invention belongs to the technical field of angle photoelectric measurement, and relates to a roll angle measurement device and method, in particular to a roll angle measurement device and method of non-contact heterodyne interference diffraction grating displacement technology. Background technique [0002] Any mechanical rail kinematic pair has three rotational degrees of freedom (pitch, yaw and roll), which are defined as pitch, yaw and roll of linear motion according to the ISO10791-2:2001 / GB / T18400.2-2010 standard Angle deviation. Among the three angle deviation detections, the measurement methods and technologies of pitch angle and yaw angle have been developed relatively mature and have high measurement resolution, such as dual-frequency laser interferometer method, autocollimator, etc. Relatively speaking, the existing roll angle measurement methods and technologies are difficult to meet the high-resolution requirements, and have always be...

AI Technical Summary

Problems solved by technology

[0003] At present, there are mainly the following types of methods for high-precision roll angle detection: First, electronic level measurement based on the direction of gravity. The difference from the reference plane can be used to measure the roll angle. Although it has the advantages of simple structure and easy operation, it cannot measure the roll angle of the vertical axis.

Second, the measurement is based on the position of the collimated laser based on the position sensitive detector (PSD). Calculate and complete the roll angle measurement, it can easily realize multi-dimensional measurement, but the measurement resolution is limited by the performance of PSD, it is difficult to improve, and it is easy to be affected by pitch angle and yaw angle

The patent with the publication number CN1335483 improves the optical path design on the basis of the polarized light phase method and increases the sensitivity of the original method by 4 times on the basis of nonlinear enhancement, but it is difficult to improve the resolution of this method and device

Fourth, roll angle measurement by interferometry. In the US Patent No. 5056921, Chaney proposed a method of completely using an interferometer to measure the roll angle to obtain high accuracy, but the system needs to install a planar reflector with the same length as the guide rail. mirror, it is difficult to apply in practice

Another laser interferometry is to use a laser interferometer to measure the linear displacement of the diagonal lines of multiple bodies, and indirectly solve 21 single-item geometric errors through the equations, including the roll angle measurement value, but this method is indirect Comprehensive measurement method, which cannot be measured in real time and is not conducive to error compensation

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