Calibration method for fast multi-line structured light vision measurement system

Abstract

The invention relates to a calibration method for a fast multi-line structured light vision measurement system. The method include the following steps that: (1) two light planes, namely the first andlast light planes, are calibrated separately, so that the unit normal vectors and distance parameters of the light planes are obtained; (2) the rotation angle and rotation vector of the two light planes are calculated through the normal vectors of the first light plane and last light plane obtained in the step (1); (3) on the basis of a characteristic that multi-line structured light is equidistantly parallel and intersects with one straight line, and the rotation angle calculated in the step (2), included angles between adjacent light planes are calculated; (4) the rotation matrix of the light planes is constructed on the basis of the included angles between the adjacent light planes calculated in the step (3) and the rotation vector calculated in the step (2); (5) the unit normal vectorsof each of intermediate planes are calculated according to the rotation matrix obtained in the step (4) and the unit normal vector of the first light plane; and (6) on the basis of the equation of the first light plane and last light plane obtained in the step (1), the common intersection line of each light plane is calculated at first, and a plurality of points are sampled, and then, the distance parameters of the equations of each of the intermediate light planes are respectively calculated.

Description

technical field [0001] The invention relates to the calibration of a structured light-based visual measurement system in the field of computer vision applications, in particular to a fast calibration method for a line-structured light visual measurement system whose intersecting line images have equidistant parallel characteristics when projected vertically on an imaging plane. Background technique [0002] Line structured light measurement is a method of projecting a line structured light plane onto the target surface to obtain the three-dimensional coordinates of the point where the plane intersects with the target surface to be measured. In practical applications, by adding the third-axis motion information to stitch the intersection contours together, the three-dimensional surface contours of complex target surfaces can be detected. Multi-line structured light is an extension of single-line structured light. It avoids adding third-dimensional motion information, and can ...

AI Technical Summary

Problems solved by technology

At present, the multi-line structured light projectors on the market can project as many lines as 7 lines to 81 lines (usually an odd number), but the calibration process has always followed the calibration strategy of single-line structured light, that is, firstly detect one by one, Indexing and estimating the feature points on the intersection image of each light plane and the target, and then obtaining the light plane equation, the steps are cumbersome, and the maximum calibration accuracy of the system depends on the calibration error of individual light planes

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