Camera calibration method for large field-of-view high-accuracy vision measurement

Abstract

The invention provides a camera calibration method for large field-of-view high-accuracy vision measurement and belongs to the fields of measuring and testing. According to the camera calibration method for the large field-of-view high-accuracy vision measurement, a single infrared light-emitting diode (LED) with self-adapting brightness is used as a target spot, and the target spot is fixed on a three-dimensional numerical control mechanical device and is controlled to move to a preset space position. A virtual stereo target is constructed in three-dimensional space. When the target spot reaches the preset space position, a camera subjects the target spot to image acquisition. The virtual stereo target is shot in a plurality of directions by means of freely moving the camera, so that a plurality of virtual stereo targets are distributed in calibration space of the whole camera, when the shooting of the virtual stereo target in each direction is achieved, a set of inner parameters and a set of outer parameters are calculated to serve as trailing optimized initial values. Finally, the calibration parameters of the virtual stereo target shot in multiple directions are subjected to whole optimization. The camera calibration method for the large field-of-view high-accuracy vision measurement can effectively improve the accuracy of the large field-of-view camera.

Description

technical field [0001] The invention belongs to the field of measurement and testing, and relates to a camera calibration technology, in particular to a camera calibration method for high-precision visual measurement of a large field of view. Background technique [0002] In recent years, measurement systems based on machine vision have been more and more used in the processing, assembly and quality inspection of aviation, automobile and other industrial fields. The calibration accuracy of the camera, the core measurement component, directly affects the measurement accuracy of this type of measurement system. . The process of camera calibration is the process of determining the parameters in the camera imaging model according to several three-dimensional space points (target points) and their corresponding two-dimensional image points on the imaging plane. The parameters of the camera include intrinsic parameters and extrinsic parameters. Intrinsic parameters are inherent ...

AI Technical Summary

Problems solved by technology

[0005] Technical problem: the present invention aims to overcome the deficiencies of the prior art, and proposes a camera calibration method for high-precision visual measurement with a large field of view, which solves the problem that large-scale high-precision physical targets cannot be produced, and small-size targets (including virtual Stereo target) cannot cover the entire measurement space, resulting in the calibration result not being able to truly reflect the camera imaging model in the entire large field of view, and thus the calibration accuracy is low

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