METHOD FOR CALIBRATING CAMERA MEASUREMENT SYSTEM

摘要

This method is characterized in that a ring-shaped jig is disposed on a workpiece on a machine tool, and the optical axis of a camera is aligned parallel to a single axis of the coordinate system of the machine tool. The jig is photographed using the camera in which the horizontal direction or the vertical direction of the camera is aligned with an axial direction other than the signal direction of the machine tool, and the circumferential shape of the jig in the image photographed by the camera is extracted as a contour. The center position of the jig in the image is calculated from the contour while all the distortion correction coefficients in tangential direction and all the distortion correction coefficients in the radial direction are ignored and set to zero. The displacements of the main point of the camera are all set to zero so as to be included in the translation distance of the camera. The translation distance, which is an external parameter of calibration, is calculated on the basis of the center position of the jig in the image and the known three-dimensional center position of the jig.

主权项

1. A method for calibrating camera measurement system characterized of comprising:
setting a ring-shaped calibration jig at a workpiece on a machining tool; aligning an optical axis of a camera parallel to a single axis of a coordinate system of said machining tool and also aligning a horizontal direction or a vertical direction of said camera with an axial direction other than a direction of said single axis of said machining tool wherein an image of said calibration jig is photographed using said camera; extracting a circumferential shape of said calibration jig in said image as a contour; calculating a center position of said calibration jig in said image from said contour while all the distortion correction coefficients in a tangential direction of said camera and all the distortion correction coefficients in a radial direction of said camera are ignored and set to zero; and calculating a translation distance as an external parameter of calibration on the basis of said center position of said calibration jig in said image and a known three-dimensional center position of said calibration jig.