Large field of view camera calibration method based on precision two-axis turntable and laser tracker

Abstract

The invention relates to a large field of view camera calibration method based on a precision two-axis turntable and a laser tracker. The large field of view camera calibration method is characterizedin that the precision two-axis turntable and a laser tracker target ball perform a rotary motion together, and a conversion matrix from a tracker coordinate system to a turntable coordinate system issolved; an optical reflection ball is used as an optical reference point of the camera calibration and is fixed in front of the turntable; a position of an optical reflection ball center is established in the turntable coordinate system through precise exchange between the optical reflection ball and the tracker target ball and tracker measurement; the camera and the turntable perform two-dimensional rotation together to shoot the optical reference point and simultaneously record an angle value of each stand position, and a virtual calibration control field is established; an elliptical contour of the reflection ball in the image is fitted to calculate an image position of a calibration target center; and a minimum objective function is established on the basis of a camera imaging model to perform camera calibration. The invention is suitable for completing high-precision camera internal reference calibration in a large field of view environment, and is particularly suitable for occasions where change of the camera measurement depth is large and the traditional calibration target is difficult to design and manufacture.

Description

technical field [0001] The invention relates to a sensor calibration technology, in particular to a calibration method for a camera with a large field of view based on a precision two-axis turntable and a laser tracker. Background technique [0002] The measurement space of large-field visual measurement ranges from a few meters to tens of meters or even hundreds of meters. It is an important measurement method in advanced technical fields such as precision aviation visual navigation, large-scale mechanical equipment positioning, and large-scale component manufacturing and assembly. Large field of view visual measurement has an irreplaceable position in the field of measurement due to its advantages of large measurement range and non-contact measurement process. [0003] The research on calibration method and application of large field of view camera aims to solve the problems of camera calibration difficulty and low calibration accuracy in large field of view visual measure...

AI Technical Summary

Problems solved by technology

[0006] The technical solution of the present invention is to overcome the deficiencies of the prior art, and provide a large-field-of-view camera calibration method based on a precision two-axis turntable and a laser tracker, which solves the situation where the measurement depth of a large field of view varies widely and requires high calibration accuracy. In the middle, it is difficult to design the problem of matching the calibration target with the field of view

Images