Vision-based high-precision rotation angle measurement method

Abstract

The invention discloses a vision-based high-precision rotation angle measurement method. The measurement method comprises the following steps that a characteristic mark with four circular envelope rectangles is adopted, wherein the characteristic mark is fastened to the rotating surface of a rotary table, and has the same rotation angle as the rotation surface; a region of interest ROI of the image is determined based on template matching, and the influence of the similar edge of the image background on the detection of the rectangular edge in the characteristic mark is eliminated; then high-precision extraction of the rectangular long edge is realized based on the sub-pixel edge detection method of Zernike moment to obtain sub-pixel coordinates of two long edges of the rectangles; fittingof the sub-pixel coordinates of the two long edges is carried out based on a least square fitting method to obtain corresponding fitted edge straight lines and the mean value of the slopes of the twostraight line is calculated; and the rotation angle of the rotation position relative to the reference position is calculated by using an arctangent trigonometric function of the mean value of the two slopes. The method solves the problems that the existing rotation angle measurement method is limited in measurement precision, tedious in process, complex in system and the like.

Description

technical field [0001] The invention belongs to the technical field of measurement and measurement control, and is especially suitable for high-precision, stable and reliable low-frequency rotational vibration measurement. Background technique [0002] With the development of science and technology, military industry, aerospace and other scientific and technological industries have put forward higher and higher requirements for angle measurement accuracy, speed and other indicators. Therefore, it is of great significance to propose an accurate, fast and convenient angle measurement method . [0003] At present, commonly used angle measurement methods can be roughly divided into contact measurement methods and non-contact measurement methods. Among them, the most commonly used contact measurement methods are mechanical measurement methods and electromagnetic measurement methods. Mechanical measurement methods (such as multi-tooth indexing tables) have the limitations of slow...

AI Technical Summary

Problems solved by technology

[0004] Therefore, in view of the shortcomings of the current angle measurement method, such as limited measurement accuracy, cumbersome process, high system cost, and low degree of automation, the present invention proposes a high-precision, low-cost, and convenient rotation angle visual measurement method

Images