基于视觉测量的应变片空间定位及应用  

Position Determination of Strain Gauges and Applications based on Videometrics

作　　者：周书涛 李立欣 张伟[1] 巨亚堂[1] 张忠[1] 王泰然 苏志龙 张东升[2] ZHOU Shutao;LI Lixin;ZHANG Wei;JU Yatang;ZHANG Zhong;WANG Tairan;SU Zhilong;ZHANG Dongsheng(Beijing Institute of Structure and Environment Engineering,Beijing 100076,China;School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China)

机构地区：[1]北京强度环境研究所,北京100076 [2]上海大学力学与工程科学学院,上海200444

出　　处：《实验力学》2023年第2期176-184,共9页Journal of Experimental Mechanics

摘　　要：在大型航天结构舱段试验中,通常需要粘贴大量的应变片来获取结构的应变测试数据。为了能够准确定位结构舱段上的应变片位置,本文研究了基于单目视觉测量技术的应变片空间坐标重建方法。该方法采用一台单反相机,从不同视角连续对构件进行拍摄,获得一组包含圆环编码点和应变片的图像序列;通过检测编码点图像坐标,构建相邻帧之间的匹配关系,然后基于相对定位原理估计相机姿态信息;再利用深度学习技术提取图像中的应变片坐标,结合估计的姿态信息对提取的应变片进行立体匹配,并且采用三角测量方法重构应变片空间坐标,从而实现应变片的三维定位。利用所研究的方法,分别对铝质平板和圆筒上粘贴应变片的三维坐标、碳纤维标尺的长度进行了定位。定位结果表明,该方法的重复定位精度优于0.05mm,三维点距离测量精度优于0.1mm。In the cabin test of large aerospace structures,a large number of strain gauges is usually required in measuring the localized structural strain.In order to accurately determine the position of strain gauges on the structural cabin,a novel method based on the monocular vision measurement technology has been proposed.A SLR camera is adopted to capture images of the structure from different angles,after a set of circular coding markers and strain gauges are attached on the surface.By detecting the image coordinates of coding markers,the matching relationship between adjacent frames is constructed,which achieves camera calibration.Deep learning technology is employed in recognizing strain gauges,and the image coordinates of strain gauges are extracted to rebuild the corresponding spatial coordinates according to triangulation.The developed method has been applied to determination of the spatial coordinates of strain gauges on the aluminum flat plate and cylinder,and the markers on a carbon fiber reinforced composite bar,respectively.The experimental results show that the repeated positioning accuracy of this method is better than 0.05mm,and the errors in distance between markers are less than 0.1mm.

关 键 词：应变片 三维坐标定位 深度学习 视觉测量 

分 类 号：O348.1[理学—固体力学]