CAD model and triangular mesh full-automatic registration method and device

Abstract

The invention discloses a CAD model and triangular mesh full-automatic registration method and device. The method comprises the following steps: s1, reading a nominal CAD model and an initial scanningtriangular mesh; extracting the vertex of the initial scanning triangular mesh as a source point cloud, and taking the vertex of the CAD triangular mesh subdivided by the nominal CAD model as a target point cloud; s2, sampling the source point cloud and the target point cloud, and calculating a normal vector of a sampling point; s3, taking the sampling points as feature points, and using FPFH fordescribing the feature points; s4, for the target point cloud feature points, constructing a kd-tree in an FPFH space; selecting four feature points from the source point cloud feature points and searching four nearest neighbor points in the target point cloud to form four corresponding point pairs; s5, removing error point pairs quickly; s6, using the four corresponding point pair estimation basic matrixes as iteration initial values to repeat the steps s4 and s5 to carry out RANSAC iteration to obtain an effective point pair set; s7, performing singular value decomposition on the effectivepoint pair set to obtain a rotation translation matrix; and s8, performing rotational translation on the source point cloud by using the rotational translation matrix to complete registration.

Description

technical field [0001] The invention relates to the technical field of industrial digital detection, in particular to a method and device for automatic registration of a CAD model and a triangular grid. Background technique [0002] In recent years, with the wide application of digital inspection equipment such as coordinate measuring machines, three-dimensional scanning systems, and CT measuring instruments in the industrial field, digital inspection technology has played a vital role in the dimension measurement of large and complex parts and the assurance of manufacturing accuracy. effect. [0003] In the actual detection process, the measurement accuracy of the triangular grid obtained by the digital detection equipment can generally meet the actual measurement requirements. However, since the scanned triangular grid is different from the origin of the CAD model in the space coordinate system, this It will affect the subsequent dimensional deviation analysis, and may ev...

AI Technical Summary

Problems solved by technology

However, due to the difficulty in identifying geometric features of complex point cloud models, and the poor consistency of point cloud models of different parts, this registration method will lose key features that reflect the manufacturing quality of parts, resulting in low accuracy of registration results , unstable, not very practical

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