Calibration method of pose position-free constraint line laser monocular vision three-dimensional measurement sensor parameters

Abstract

The invention provides a calibration method of pose position-free constraint line laser monocular vision three-dimensional measurement sensor parameters and belongs to the technical fields of optical measurement and mechanical engineering technologies. After basic data are extracted, imaging points are sequenced according to the invariance of a vector quantity cross product direction set composed of the imaging points of target feature points in any shooting pose position, and corresponding relation between the target feature points and the imaging points is built. Light plane feature points are extracted through quadrilateral intersection composed of a light knife central point set fitting straight lines and the target feature points, and a three-dimensional coordinate is calculated according to an intersection invariance principle. Inner and outer diameters in a monocular vidicon and light plane diameters of a line laser projector are optically fitted and calculated, and accurate calibration of the line laser monocular vision three-dimensional measurement sensor parameters is achieved. In calibration, a target can freely move and rotate completely, pose position placing is free of restraint, the same group of calibration images is shared for calibration of two parts of diameters, the calibration accuracy of a three-dimensional measurement sensor is ensured, and simultaneously calibration steps are simplified.

Description

Technical field: [0001] The invention relates to a calibration method of a line laser monocular vision three-dimensional measurement sensor, in particular to a parameter calibration method of a monocular vision three-dimensional measurement sensor without pose constraints. It belongs to the technical fields of optical measurement and mechanical engineering. Background technique: [0002] A typical line laser monocular vision three-dimensional measurement sensor consists of a line laser projector and a monocular camera, and its parameters include the internal and external parameters of the monocular camera: equivalent focal length, principal point coordinates, transformation from the target coordinate system to the monocular camera coordinate system Matrix; light plane parameters of the line laser projector: the parameters of the line laser light plane equation. [0003] The traditional calibration methods of line laser monocular vision three-dimensional measurement sensors ...

AI Technical Summary

Problems solved by technology

However, the production of targets used in these methods is relatively complicated, and the calibration operation is limited by the calibration reference

In the prior art, the calibration method proposed by V.Niola et al. in the paper A method for the calibration of a 3-D laser scanner (Robotics and Computer-Integrated Manufacturing, 2011, 27:479-484) requires a mechanical The platform controls the precise movement of the target, which is easy to introduce mechanical errors and limits the degree of freedom of the calibration operation; , 23(1):59-67) proposed a calibration method based on a freely moving plane target. Although this method avoids the mechanical error introduced by controlling the target displacement during calibration, when the square checkerboard target rotates around its plane When the rotation angle of the normal vector of is slightly larger, the identification of the row and column of the target grid will be ambiguous, resulting in an error in the correspondence between the target feature point and its imaging point in the cross-ratio invariant principle, and the light plane cannot be correctly calibrated; therefore, When moving the target, it is still necessary to avoid the rotation of the target around the normal vector of the plane where it is located. The position of the target is not completely free, and the operation is still subject to great restrictions.

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