基于对称性的双叶螺旋桨修复方法

The reparation method for the twin-blade propeller based on symmetry

对双叶螺旋桨桨叶的破损区域进行修补时,使用一般的缺损修补方法往往精度不够而且会影响桨叶的气动性能。针对该问题,提出一种基于对称性的双叶螺旋桨桨叶修复方法。首先,利用主成分分析法求得旋翼直径轴;然后,将桨叶点云绕直径轴旋转,使用迭代的方法逐步调整旋转角度将桨叶点云投影至二维平面,同时采用平均偏差值计算方法检测二维点云外轮廓的反射对称性,利用反射对称性确定螺旋桨的旋转轴轴向;最后,根据螺旋桨的旋转对称性,构建包围盒检索缺损区域的旋转对称点,若存在旋转对称点,则用其填补缺损区域。对所提方法进行了实验验证,结果表明该方法能实现破损叶片的高精度修复。

Aiming at the low-precision and influencing the aerodynamic performance at filling the holes in point cloud of twin-blade propeller,it proposes a reparation method based on symmetry.It uses the principal component analysis to calculate the long axis of propeller,rotates the point cloud of propeller around its long axis,changes the rotation angle via iteration method and projects them to 2D space.Then the method detects the mirror reflection symmetry of 2D contour based on a mean deviation method,and calculates the direction of propeller hub.Based on the character of rotation symmetry,it finds the rotation symmetry points of holes in propeller,fills the holes in these rotation symmetry points.The results show that the proposed method provides high-precision reparation of broken propeller.