Calibration method for spatial position of laser beam

Abstract

The invention provides a calibration method for a spatial position of a laser beam. The calibration method comprises the following steps: forming a laser beam calibration device by adopting a target plane and a camera provided with a telecentric lens, wherein the camera is dead against the target plane, and two target balls and four isodiametric shadow circles are arranged on the target plane; taking a coordinate system of a three coordinate measuring machine as a world coordinate system, measuring parameters of the target plane by utilizing the three coordinate measuring machine, and obtaining a normal vector of the target plane and coordinates of any point on the target plane; calculating coordinates of a projective point of the center of each target ball on the target plane; establishing a viewpoint coordinate system; acquiring an image of the target plane by utilizing the camera, and extracting a laser point, circle centers of projections of the target balls as well as pixel coordinates of circle centers of the four shade circles by virtue of a centroid method, so that the circle centers of the four shade circles are taken as control points for perspective correction of the image; establishing a relationship between coordinates of a spatial point and coordinates of projection of the spatial point in a projection plane; obtaining three-dimensional spatial coordinates of thelaser point in the world coordinate system; and fitting the spatial position of the laser beam.

Description

technical field [0001] The invention relates to a precision measurement system, in particular to a method for calibrating the space pose of a laser beam in a coordinate measurement system constructed by a laser and an electric control rotary table. Background technique [0002] In order to complete the non-contact three-dimensional coordinate measurement, the laser is combined with the electric control rotary table to build a coordinate measurement system based on angle-angle intersection. This system is similar to theodolite measurement system and consists of two measurement units, each of which is composed of It consists of two independent one-dimensional electronically controlled rotating stages and a laser. When assembling the measurement unit, the "three-axis" structure proposed by the patent application (based on the measurement method of the non-orthogonal axis laser theodolite, 201410850221.8) is adopted, and the two rotating platforms are respectively named as the h...

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Problems solved by technology

[0004] Related Papers (①Bi Chao, Fang Jianguo, Liu Jingliang, Liu Yong, Li Chengwei. Beam Direction Calibration of Laser Displacement Sensor Based on Spherical Target[J]. Optical Precision Engineering, 2015,23(3):678-685; ②JunhuaSun, JieZhang ,ZhenLiuand GuangjunZhang.Avisionmeasurementmodelolaserdisplacementsensoranditscalibrationmethod[J].Optics&LasersinEngineering,2013,51(12):1344-1352.) proposed a laser beam calibration method, but only the direction vector of the laser beam is calibrated, and its spatial position cannot be determined, if Strict requirements on experimental equipment are not suitable for widespread use. Therefore, it is necessary to continue to study the calibration method of laser beams

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