Camera calibration system and calibration method thereof

Abstract

The invention provides a camera calibration system. A calibration platform of the camera calibration system comprises an X-axis translation mechanism, a Y-axis translation mechanism, a Z-axis translation mechanism, an X-axis rotation mechanism, a Y-axis rotation mechanism, a Z-axis rotation mechanism and a fixed platform, and has 6 degrees of freedom. Meanwhile, the invention provides a calibration method of the camera calibration system. The method comprises the following steps of: establishing a coordinate system of each axis according to size parameters of the calibration platform; and obtaining a position and a direction of a calibration plate or a reference substance at any moment through recording a position of each axis by an encoder of each axis, so as to further realize translation and rotation of the calibration plate or the reference substance in any direction. The camera calibration system is capable of replacing robot platform to calibrate internal and external parametersof cameras, customized clamps fixedly connected between robots and the tail ends of the cameras are not required, and the traditional calibration method and self-calibration method can be convenientlyused, so that the system is simple to operate and flexible to use; and compared with the working manner of moving the cameras by the robots, the manner of carrying out calibration through moving thecalibration plate or the reference substance has the effect of greatly reducing the mistaken operation probability.

Description

technical field [0001] The invention relates to the technical field of camera calibration, in particular to a camera calibration system and a calibration method thereof. Background technique [0002] The camera is used in the machine vision system to obtain the target image to realize the reconstruction and recognition of the object. The premise of realizing the above functions is to establish a geometric model between the three-dimensional information of a certain point on the space object and the two-dimensional coordinate information in the image, and the parameters of the geometric model are the internal and external parameters of the camera and the light plane equation of the camera. Internal and external parameters and optical parameters need to be calibrated through experiments and calculations, so the accuracy of parameter calibration directly affects the accuracy of machine vision. [0003] At present, a variety of methods have been proposed for camera calibration,...

AI Technical Summary

Problems solved by technology

However, in many cases, it is not necessary to calibrate the hand-eye relationship between the camera and the robot, and the robot is only used to calibrate the internal parameters of the camera; and the camera calibration using the robot not only needs to customize the fixed fixture at the end of the camera and the robot, but also makes the calibration more flexible. Poor, if there is no robot at the work site, calibration cannot be carried out; moreover, since the pose of the end of the robot is directly controlled instead of the pose of the camera, it is easy to misuse when doing rotation, even if the calibration plate (reference object) exceeds The field of view of the camera needs to be compensated by moving the robot so that the calibration plate (reference object) returns to the field of view. Repeated operations are time-consuming and inconvenient

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