摇臂式喷头内流道曲面的逆向重构研究

Surface Reconstruction of Internal Runner of Impact Sprinkler Using Reverse Engineering Methods

用线切割机床将雨鸟30IBH摇臂式喷头内流道切割成a,b两部分,使三维光学扫描仪的投影光束能够到达其表面进行多视扫描,获取不同视角下流道a,b的点云数据。去除多视点云中的噪点后,用三点法拼接多视点云,得到流道a,b的点云数据;再将流道a,b的点云数据拼接成喷头内流道的点云数据;采用弦偏差采样法将点云数据精简后,用基于边的方法把点云分割成喷管和小喷嘴两部分,选择非均匀有理B样条(NURBS)模型分别按照点-线-面的顺序进行曲面重构。曲面重构的精度分析结果表明,最大几何误差为0.292 9mm,平均几何误差为0.076 2mm,满足预期的精度要求,实现了摇臂式喷头的内流道曲面重构。

In order to get the point clouds of internal runner of RainBird 30IBH impact sprinkler by 3D laser scanner,using a linear cutting machine,cut the runner into two parts so that the laser beams can arrive.Then scan the two parts and get their multi-view point clouds separately.Using three control points method to register multi-view point clouds after noise filtering to get the point clouds of the two parts.Then,get the point cloud of internal runner of sprinkler by registering the point clouds of the two parts.Reducing data of the point cloud by chordal deviation method before Edge-Based data segmentation and NURBS surfaces reconstruction.There is surface of the runner of sprinkler after trimming and merging the surfaces.Evaluate the difference between reconstructed surface and point clouds,the result shows that the max and average Euclidean difference is 0.29mm and 0.07mm,this matches expectations.