板金属冲压零件表面模型与实测点云配准研究

为研究板料零件成形后实测点与设计原型之间的制造偏差,需要将实测坐标点云数据和产品数字模型进行配准,实现设计坐标系和实测点云数据的测量坐标系的统一。以CAD模型离散点云数据为引导,将配准过程分为初步配准和精确配准两个步骤。采用基于PCA提取特征坐标系的方法进行初步配准,采用k-d tree加速的ICP算法进行精确配准,将实测点云数据和设计原型离散点云数据转换到同一个坐标系中。基于UG NX平台将经过坐标转换的实测点云数据读入到CAD模型中,得到同一环境坐标系下配准后的实测点云数据和CAD模型,为制造偏差分析提供了基础,并进行了实例验证。

Research on the Registration of Surface Model of Sheet Metal Stamping Parts and Measured Point Cloud

In order to study the deviation between measured point and design model of sheet metal parts,it is nec-essary to register the measured point cloud data and product digital mode.The process of registration is to unify the coordinate system of CAD design and the measurement coordinate system of measured point cloud data.The process was guided by the discrete point cloud data.It was divided into two steps:initial registration and accurate registra-tion.The method of extracting feature coordinates based on PCA was used for initial registration,and the ICP algo-rithm accelerated by k-d tree was used for accurate registration.Thus the measured point cloud data and discrete point cloud data were converted to the same coordinate system.On this basis,based on the UG NX platform,the transformed measured point cloud data was read into the CAD model file.The measured point cloud data and the CAD model after registration were obtained.