应用于油罐内机械臂作业的点云法矢计算方法  

Normal Vector Calculation Method of Point Cloud Applied to Manipulator Operation in Oil Tank

作　　者：程健勇 吴功平[1] 樊飞[1] 解建忠 CHENG Jian-yong;WU Gong-ping;FAN Fei;XIE Jian-zhong(School of Power and Mechanical Engineering,Wuhan University,Hubei Wuhan 430072,China;Hubei Sanjiang Aerospace Red Forest Exploration and Control Co.,Ltd.,Hubei Xiaogan 432000,China)

机构地区：[1]武汉大学动力与机械学院,湖北武汉430072 [2]湖北三江航天红林探控有限公司,湖北孝感432000

出　　处：《机械设计与制造》2021年第6期222-227,共6页Machinery Design & Manufacture

基　　金：撬装机械臂路径规划设计开发(HLMP18005)。

摘　　要：利用机械臂对油罐内壁进行改造时,对激光扫描油罐内壁得到的点云数据的处理精度,尤其是油罐点云法矢的计算准确程度,会影响到机械臂的运行情况及改造效果。考虑到传统协方差分析法对局部特征法矢估算不准确的问题,提出一种应用于油罐内壁的法矢计算方法。首先,利用栅格法和八叉树法相结合的二次剖分方法,建立点云之间的拓扑结构,并根据实际需求实现自适应的路径点的K邻域搜索;然后,采用距离和曲率加权的协方差矩阵对路径点处的法矢进行计算。使用该方法进行实验验证,结果表明,该方法对机械臂作业路径点处的法矢计算准确,满足实际改造需求。When the inner wall of the oil tank is modified by the robotic arm,the processing accuracy of the point cloud data obtained by the laser equipment scanning tank inner wall,especially the calculation accuracy of the tank point cloud vector,will affect the operation of the arm and the transformation effect.Considering that the traditional covariance analysis method is not accurate in estimating the normal vector of some areas in the tank,a method of calculating the normal vector applied to the inner wall of the tank is proposed.Firstly,using the quadratic subdivision method of grid method and octree method,the topological structure between point clouds is established,and the adaptive K-Neighbor search of path points is realized according to actual needs.Then,the normal vector at the path points is calculated using the distance and curvature weighted covariance matrix.The experimental verification is carried out by using this method and the results show that this method can calculate the normal vector at the path points of the manipulator operation and meet the actual transformation requirements.

关 键 词：机械臂 油罐 混合拓扑 K邻域搜索 点云法矢 

分 类 号：TH16[机械工程—机械制造及自动化] TP271.4[自动化与计算机技术—检测技术与自动化装置]