A 3D Coordinate Measurement Method Based on Ray Angle Calibration

Abstract

The invention discloses a three-dimensional coordinate measurement method based on light ray angle calibration. The method includes the steps of firstly, measuring coordinates of an external aperture and the upper angular point of a target with a two-dimensional checkerboard reference object as a calibration target; secondly, projecting light ray passing through the aperture through the angular point to all planes of a world coordinate system, and calculating the included angle between the light ray and the optical axis of a camera; thirdly, shooting a single image, obtaining coordinates of a lower angular point of an image coordinate system through a Harris angular point detection algorithm, and obtaining the included angles between the light rays, passing through the aperture, of all pixel points on the CCD target face and the optical axis according to the pinhole camera principle with pixels as unit interpolations; fourthly, calculating spatial coordinates of any point on the calibration target face through the angle matrix. The requirement of the method for devices is low, the system structure is simple, the measurement result has high accuracy, and real-time measurement can be completed.

Description

technical field [0001] The invention relates to a three-dimensional coordinate measuring method based on light angle calibration. Background technique [0002] Optical 3D measurement methods are widely used in machine vision, industrial inspection, biomedicine and many other fields. In the field of optical three-dimensional measurement, in order to obtain the three-dimensional coordinates of the object to be measured, the camera will be calibrated first, and the accuracy of the calibration will directly affect the final measurement accuracy. Camera calibration requires the help of targets with known parameters, which can be divided into two types according to their types: two-dimensional planar targets and three-dimensional three-dimensional targets. Using a three-dimensional stereo target to calibrate the camera, the calibration process is simple and the accuracy of the result is high. However, due to the high production cost of the three-dimensional stereo target and the ...

AI Technical Summary

Problems solved by technology

The plane calibration method proposed by Zhang is currently the most widely used two-dimensional plane calibration method. This method has high calibration accuracy and is easy to implement. However, during the calibration process, it needs to take multiple images of poses and cannot achieve fast measurement.

[0003] In the three-dimensional measurement method, neither the coordinate measurement based on camera block calibration proposed by Jia Zhenyuan et al. nor the traditional three-coordinate machine measurement method can solve the fast and real-time problem. In order to overcome the above shortcomings, the present invention proposes a Three-dimensional Coordinate Measurement Method Based on Ray Angle Calibration

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