针对航空发动机叶片型面的高精度检测需要, 阐述了基于激光扫描点云的叶片型面三维重构技术, 并对型面重构误差进行了深入分析.该技术对测量数据进行点→线→面数学模型处理, 先由点云采用端点一阶导矢连续法拟合出光顺曲线, 再基于截面曲线的非均匀有理B样条曲面拟合, 依据曲面网格线光顺法重构出曲面, 然后根据空间测点到曲面的最小距离对重构误差进行分析.最后通过叶片型面激光测量装置对算法进行了验证.实验结果表明,重构误差小于0.019 mm, 满足对叶片型面质量的评价要求.

Aiming at the need of high-precision detection of aeroengine blade profile, the 3D reconstruction technology of blade profile based on laser scanning point cloud was described, and the error of profile reconstruction was analyzed. The measurement data was processed through the mathematical model of point → line → surface. First, the smoothing curve is fitted by the first-order end-point vector method of point cloud, then the Non-Uniform Rational B-Splines surface is fitted based on the section curve, smooth surface method is used to reconstruct the surface, and the reconstruction error is analysised by calculating the minimum distance between the space measuring point and the surface. Finally, the algorithm is verified by the blade profile laser measuring device. The experimental results show that the reconstruction error is less than 0.015 mm, which meets the evaluation requirements of blade profile quality.