一种基于非完整点云数据的航空发动机叶片边缘半径获取方法

A Method for Obtaining Edge Radius of Aeroengine Blade Based on Incomplete Point Cloud Data

非接触测量技术不依赖叶片原始设计模型,快速获取叶片的关键几何参数,但在叶片边缘高曲率区域获得的点云稀疏散乱,以至于获取叶片前后缘半径困难。针对此问题,提出了一种基于非完整点云数据叶片前后缘半径获取方法。该方法通过点云分割,获得叶盆与叶背多项式形式的轮廓线,运用二分法逼近方法,获得同时与叶盆和叶背相切的叶缘圆弧。与接触式三坐标测量机测量叶缘半径得到的结果进行对比,偏差<30%。该方法在一定程度上能够改善高曲率曲面非接触测量点云失真问题,为叶片快速重构提供了参考。

The non-contact measurement technology does not rely on the original design model of the blade and quickly obtains the key geometric parameters of the blade,but the point clouds obtained in the area of high curvature of the edge of the blade are sparse and scattered,so that it is difficult to obtain the radius of the leading edge of the blade.In order to solve this problem,a method to obtain the leading edge radius of blade based on incomplete point cloud data is proposed.In this method,the contours of leaf basin and leaf back are obtained by point cloud segmentation,and the leaf edge arc tangent to leaf basin and leaf back is obtained by dichotomy approximation method.Compared with the results obtained by measuring the blade edge radius by the contact CMM,the deviation is less than 30%,which is in line with the expectation.This method can improve the point cloud distortion of non-contact measurement of high curvature surface to a certain extent,and provides a useful reference from the rapid reconstruction of blades.