Multi-measuring-point planeness evaluation method based on support vector classification

Abstract

The invention discloses a multi-measuring-point planeness evaluation method based on support vector classification. The method comprises the following steps: sampling points on a tested surface to obtain a three-dimensional coordinate measurement value of each point; calculating a least square surface corresponding to a measurement point set; with the least square surface as a reference, removing measurement points with a small residual absolute value; moving measurement points with a big residual absolute value for the same distance respectively along the positive direction and the negative direction of the normal direction of the least square surface to form a linearly separable positive point set and negative point set; calculating the maximum interval plane of the positive point set and the negative point set with a linearly classified support vector machine method; and calculating a planeness value according to the plane. According to the multiple-measuring-point planeness evaluation method, the calculation data amount in the multiple-measuring-point planeness evaluation can be reduced and the calculation efficiency and the accuracy of an evaluation result are obviously improved.

Description

technical field [0001] The invention relates to a flatness evaluation method, in particular to a multi-measurement point flatness evaluation method based on support vector classification. Background technique [0002] With the development of the national economy and the improvement of advanced manufacturing levels, in modern industrial manufacturing, especially in the fields of precision manufacturing, there are high precision requirements for the geometrical and dimensional accuracy of workpieces and structures. As one of the most common geometric dimensions of industrial products, planes are often used as pressure-bearing planes and reference planes in practical applications. If the flatness of the workpiece exceeds the design requirements, it will lead to uneven force on the pressure bearing surface, which will easily cause local deformation or damage of the pressure bearing surface, or cause the geometric dimensions of the components based on the plane to be out of align...

AI Technical Summary

Problems solved by technology

The calculation speed of the least square method is faster, but it is difficult to guarantee the evaluation accuracy by using the least square plane instead of the minimum area plane; the calculation accuracy of the search method is high, but it is easy to fall into a local optimum in the iterative search; the calculation accuracy of the geometric method is High, but it is necessary to obtain the minimum area plane through all enumeration methods, and the calculation is complicated

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