圆结构光系统深孔圆度测量方法研究
Deep hole roundness measurement method of circular structured light system
陈振亚 1马卓强 2李翔 3沈兴全 2杨尚进 2苗鸿宾 2卢传杰4
作者信息
- 1. 中北大学机械工程学院,山西太原 030051;中国船舶集团有限公司第七一三研究所,河南郑州 450015;恶劣环境下智能装备技术山西省重点实验室,山西太原 030051
- 2. 中北大学机械工程学院,山西太原 030051;恶劣环境下智能装备技术山西省重点实验室,山西太原 030051
- 3. 中国船舶集团有限公司第七一三研究所,河南郑州 450015
- 4. 山东普利森集团有限公司,山东德州 253000
- 折叠
摘要
圆结构光系统测量深孔(通孔)圆度时存在激光器、相机和深孔难以保持平行或同轴的问题,导致无法测量准确的圆截面,从而产生系统误差.搭建了基于圆结构光的测量系统,分析了系统误差的产生机理并提出了 一种基于圆结构光系统测量圆度的方法,可对系统误差进行一定补偿:首先,获取待测深孔的内表面高分辨率三维点云,拟合点云轴线,通过刚体变换将三维点云变换到深孔轴线与相机光轴平行的位置;然后,选定一个测量截面,搜索该截面上的点和与该截面范围较近的点作为圆度评定点;最后,采用网格搜索算法完成圆度评定.测量实验的结果表明,该方法对于圆度误差的补偿效果良好,其中测量不确定度为4.78 μm.
Abstract
Objective The circular structured light based measurement system can generate circular structured light by reflecting a laser beam through a conical reflector,and utilizing laser triangulation and close-view photogrammetry algorithms to calculate three-dimensional coordinates.This kind of measurement system has been widely studied by researchers due to its advantages such as high flexibility,high accuracy and simple structure.The current circular structured light system has certain problems in measuring roundness.It is difficult for the laser,the camera and the deep hole to be measured to be parallel or coaxial,which leads to the inability to measure the accurate circular cross-section.A measurement system based on circular structured light is constructed,the mechanism of systematic error is analyzed and a method based on the circular structured light system to measure circularity is proposed,which provides some compensation for systematic errors.Methods The mechanism that generates systematic errors in the measurement of roundness by the circular structured light system is analyzed(Fig.3).A high-precision electric linear slide is used to move the deep hole parts to be measured to complete the full-field measurement,and a high-resolution point cloud is obtained and fit the axis.Through the Rodrigues formula,the inner surface point cloud rigid body will be transformed to the point cloud axis and z-axis parallel to the location of the point cloud axis,searching for the z coordinate near the point as a cross-section of the roundness of the assessment point(Fig.4).The roundness evaluation is completed by the grid search algorithm(Fig.5).Results and Discussions The compensation by the proposed method works well in roundness measurement experiments,in which the measurement uncertainty is 4.78 μm(Tab.3).For the circular structured light measurement system,a long rod can be assembled after the laser to increase the axial measurement range of the system.For the proposed circular structured light roundness measurement method,the resolution of the 3D point cloud can be improved by reducing the step length of the motorized linear slide to further improve the measurement accuracy.Conclusions A three-dimensional measurement system of circular structured light is built,the error generated when the circular structured light system measures roundness is analyzed,and a method based on the circular structured light system to accurately measure roundness is proposed.It is verified that the use of the method to measure roundness has a good compensating effect through the measurement experiments.
关键词
圆结构光/圆度测量/刚体变换/误差补偿Key words
circular structured light/roundness measurement/rigid body transformation/error compensation引用本文复制引用
基金项目
国家自然科学基金项目(52005456)
山西省专利转化专项计划项目(202305006)
中央引导地方科技发展专项(YDZJSX2022A032)
山西省基础研究计划面上项目(202303021221109)
出版年
2024
NETL
NSTL
维普
万方数据