Galvanometer scanning system calibration method based on double checkerboards

Abstract

The invention discloses a galvanometer scanning system calibration method based on double checkerboards. Calibration devices used by the method are two checkerboard calibration plates which are the same in specification and are mutually fixed at a certain angle. The method comprises the following steps: shooting a plurality of calibration device images in different postures by using a camera, segmenting two calibration plates in the same image by using an image segmentation algorithm, and performing calibrating according to a Zhang Zhengyou calibration method to obtain internal parameters andexternal parameters of the camera; and then keeping the last posture of the calibration device unchanged, and controlling the galvanometer lens to rotate and controlling the camera to expose and collect images to obtain laser stripe images projected to the two calibration plates under different light planes; and fitting high-precision calibration point obtained through image processing and calculation to obtain a light plane equation, and then acquiring rigid body transformation between a galvanometer coordinate system and a camera coordinate system to realize overall calibration of the galvanometer scanning system. The required calibration device is easy to obtain, the calibration steps are simple, the speed is high, and the precision is high.

Description

technical field [0001] The invention belongs to the technical field of calibration of an optical three-dimensional scanning system, and in particular relates to a calibration method of a vibrating mirror scanning system based on double checkerboards. Background technique [0002] Optical three-dimensional measurement has the characteristics of high precision, high efficiency and non-contact. It has been widely used in quality inspection, dimension measurement, reverse engineering and many other fields. Among them, the linear structured light scanning technology has become one of the most widely used three-dimensional measurement methods because of its high precision, simple structure, and high stability. [0003] The traditional line structured light scanning system consists of a light source, a camera and a mechanical scanning device. According to the principle of laser triangulation measurement, the three-dimensional coordinates of a single line are calculated, and the sca...

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Problems solved by technology

[0006] Aiming at the problems existing in the existing calibration methods, the purpose of the present invention is to provide a calibration method for the galvanometer scanning system based on double checkerboard grids, which is simple and flexible in operation, fast in calibration speed, high in precision, and low in cost.

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