| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that it is difficult to create a calibration jig and a calibration method is complicated.SOLUTION: A ring-shaped calibration jig 1 is installed in a work on a machine tool, an optical axis of a camera 2 is aligned in parallel with one axis in a coordinate system of the machine tool, and the jig 1 is imaged by the camera 2 aligning a horizontal direction or a vertical direction of the camera 2 with any other axial direction than the one axis of the machine tool. In the image captured by the camera 2, a circumferential shape of the jig 1 is extracted as a contour 1a, and a center position 1b of the jig 1 in the image is calculated from the contour 1a. On the other hand, all a tangential direction distortion correction coefficient and a radiation direction distortion correction coefficient of the camera 2 are ignored and defined as "0" and all the displacement of a principal point of the camera 2 is regarded as including a translational moving amount of the camera and defined as "0". On the basis of the center position of the jig 1 in the image and a known three-dimensional center position of the jig 1, the translational moving amount that is an external parameter of calibration is calculated. |
