Abstract: Aiming at the structural difficulties of the thin thickness of the leading and trailing edges of the blades and the sharp change of the curvature, the least square method was used to fit the ellipse of the discrete points of the blade section including the leading and trailing edges and part of the blade body. By setting the three error constraints of the average distance, maximum distance and subtraction of slope, the boundary of the leading and trailing edges was identified. The elastic tool flag wheel suitable for the leading and trailing edge polishing was selected, and the polishing model of the flag wheel was simplified. Starting from the polishing of a single abrasive particle, the relationship between the compression of the flag wheel and the polishing force during the polishing processes was explored. Based on the Hertz contact theory and the improved equal chord height error method, the step spacing was determined. Finally, the blade was clamped by the robot, and the comparison experiments of lateral polishing and longitudinal polishing were carried out by means of flag wheel polishing. Both polishing methods may ensure that the values of surface roughness are less than 0.4 μm and the profile errors are less than 0.08 mm, which may meet the dimensional accuracy and surface quality requirements of the blades.

Key words: leading and trailing edge, ellipse fitting, flag wheel, Hertz contact theory, equal chord height error method

摘要： 针对叶片前后缘厚度小、曲率变化急剧的结构难点，利用最小二乘法对叶片截面前后缘和部分叶身处的离散点进行椭圆拟合，通过设置平均距离、最大距离和斜率差三个误差约束条件来确定前后缘与叶盆叶背临界点，精确识别叶片前后缘；选取适合抛磨前后缘的弹性抛磨工具百叶轮，简化百叶轮抛磨模型，从单颗磨粒抛磨出发，探究抛磨过程中百叶轮压缩量与抛磨力的关系，并基于Hertz接触理论和改进的等弦高误差法确定步长行距。最后通过机器人夹持叶片、百叶轮抛磨的方式进行横抛、纵抛实验。两种抛磨方式横抛后表面粗糙度均小于0.4 μm，轮廓度误差小于0.08 mm，均能满足叶片的尺寸精度和表面质量要求。

关键词: 前后缘, 椭圆拟合, 百叶轮, Hertz接触理论, 等弦高误差法