一种基于机械式拼接的结构光扫描测量方法

Structured light scanning measurement method based on mechanical splicing

测量大尺寸零部件一般需要较大的测量范围,而高精密扫描传感器往往视野较小。为了解决该矛盾,提出了一种基于机械式拼接的结构光扫描测量方法,通过结构光扫描仪获取局部高精点云,并利用高精十字平移台实现数据拼接。分析了测量系统的组成和测量原理,提出了一种基于加权非线性优化的外参标定方法,求解出结构光扫描仪和十字平移台之间非实物坐标系的变换关系。在实验中验证了系统在300 mm的测量范围内球心距的均方根误差(root-mean-square error,RMSE)优于45μm;同时对实物进行了测量,检验了测量系统的实用性。

The measurement of large-size components needs a larger measurement range,while the high-precision scanning sensor has a small field of view in most cases.In order to solve this contradiction,a structured light scanning measurement method based on mechanical splicing was proposed.The partial high-precision point cloud was obtained by structured light scanner and the data splicing was realized by high-precision cross translation platform.Firstly,the composition and measurement principle of the system were analyzed,and an external parameter calibration method based on weighted nonlinear optimization was proposed to solve the transformation relationship of the intangible coordinates between the structured light scanner and the cross translation platform.Finally,it was verified in the experiment that the root-mean-square error(RMSE)of sphere-center distance was better than 45μm within the measurement range of 300 mm.And the feasibility of the proposed measurement system was verified by measuring the physical components.