Method for determining maximum thickness of blade based on moving least square method

Abstract

The invention discloses a method for determining a maximum thickness of a blade based on a moving least square method. The method comprises the steps of: acquiring a plurality of sections for a blade to be measured and respectively generating corresponding point cloud data; extracting the point cloud data to acquire a convex hull, acquiring front and rear edge graphics of the blade section by matching, and acquiring data points reflecting two areas including a blade section basin and a section blade back; acquiring an initial position associated with the maximum thickness of the blade by an iterative algorithm; matching near the acquired initial position by the moving least square method, so as to acquire more intensive related data points on the blade basin area and the blade back area; and performing the iterative algorithm again by using the acquired related data, and finally determining the maximum thickness of the blade. The invention further discloses a corresponding convex hull optimized extracting method. Through the method, the maximum thickness accuracy of the acquired blade can be greatly improved, and accuracy of the measured result can be simultaneously ensured while calculating steps are reduced.

Description

technical field [0001] The invention belongs to the technical field of blade processing, and more specifically relates to a method for determining the maximum thickness of a blade and a corresponding method for improving blade processing quality. Background technique [0002] For a variety of equipment such as aeroengines, steam turbines, ship propeller blades, etc., in order to meet the requirements of high performance, operating safety, reliability and life of the engine, the blades must have precise dimensions, precise shapes and strict surface integrity sex. The geometry and size of the blade affect the performance of the machine to a large extent, and the main parameters used to describe the characteristics of the blade are the diameter of the leading and trailing edges, the maximum thickness, and the length of the mid-arc. Now it is possible to use industrial CCD cameras and laser scanning technology in non-contact measurement to obtain the dense three-dimensional poi...

AI Technical Summary

Problems solved by technology

[0003] The traditional method for extracting leaf characteristic parameters is to use the fitting method to fit the curve, but because the fitted curve does not pass through the original data points, there is a large fitting error in the fitting process, so this must Will lead to poor accuracy of extracted parameters

In addition, since the non-contact measurement uses two-dimensional images as input, and uses stereo vision, phase profilometry, etc. to calculate the third-dimensional coordinate values, limited by the measurement distance, the directly collected point cloud reflecting the surface properties of the blade is in the same three-dimensional coordinates as the designed surface. There may be different scale deformations

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