Grid patch retrieval method for curved surface part measurement points based on included angle method

Abstract

The invention discloses a grid surface patch retrieval method for curved surface part measurement points based on an included angle method. The method comprises the following steps of: step A, acquiring surface patch data of each grid surface patch in an STL file one by one; step B, determining three connecting lines between the measuring point and the three vertexes of the currently selected grid patch; step C, obtaining the degree of an included angle between every two of the three connecting lines; step D, judging whether the sum of the degrees of the three included angles is equal to 360 degrees or not, if yes, taking the selected grid surface patch as the grid surface patch corresponding to the measurement point, and entering the step E, if not, judging that the selected grid surface patch is not the grid surface patch corresponding to the measurement point, and returning to the step B; and step E, obtaining the normal vector direction of the grid surface patch to drive the side head to move. According to the method, direct data processing operation of the STL file corresponding to the triangular mesh model is achieved, the outer normal vector direction of the model contour corresponding to the measuring point is rapidly obtained by judging the relation of the included angles formed by the connecting lines of the measuring point and the three vertexes of the mesh patch, and a measuring head for precision detection is effectively driven to move.

Description

technical field [0001] The invention relates to the precision technical field of curved surface parts, in particular to a grid patch retrieval method based on an included angle method for measuring points of curved surface parts. Background technique [0002] In the production process of complex curved surface parts, it is necessary to use corresponding detection technology to detect and control its machining accuracy. Among them, the detection technology based on the three-coordinate measuring machine (CMM) is often used for the shape and position accuracy detection of precision parts. At present, the 3D data of parts with complex curved surfaces is often stored as a parametric model in the computer, and any shape data information in it is accurately recorded through digital information such as shape features or parametric surfaces. By retrieving the recorded digital information, the normal vector direction of the part shape corresponding to the measurement point is direct...

AI Technical Summary

Problems solved by technology

Among them, the direction information of the normal vector of the patch can be directly obtained according to the stored data of the STL file, but the retrieval operation of the grid patch corresponding to the measurement point lacks a direct method

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