基于DIC多相机视频引伸计的动态变形测量  

Dynamic Deformation Measurement Based on DIC Multi-Camera Video Extensometer

作　　者：陈晓帅 王立忠 安文雅 刘家乐 Chen Xiaoshuai;Wang Lizhong;An Wenya;Liu Jiale(College of Mechanical Engineering,Xinjiang University,Urumqi 830046,Xinjiang,China;State Key Laboratory for Manufacturing Systems Engineering,College of Mechanical Engineering,Xi'an Jiaotong University,Xi'an 710049,Xinjiang,China)

机构地区：[1]新疆大学机械工程学院,新疆乌鲁木齐830046 [2]西安交通大学机械制造系统工程国家重点实验室,陕西西安710049

出　　处：《应用激光》2025年第1期165-174,共10页Applied Laser

基　　金：国家自然科学基金地区科学基金项目(51865057)。

摘　　要：为实现多相机视频引伸计图像的动态变形测量,基于数字图像相关法和物点重投影理论,提出并实现一种大视场下多相机视频引伸计图像的追踪匹配方法,可以将其应用在材料的大变形应变测量中。首先,对多个相机进行全局标定,解算出各个相机之间的相机坐标系与世界坐标系的矩阵变换关系;其次,对视频引伸计采集的序列图像的像点,运用物点重投影理论实现像点在视频引伸计各个相机图像之间的穿越追踪。最后,推导多相机视频引伸计应变测量的公式,搭建多相机的视频引伸计应变测量平台。通过对Q235低碳钢和铝合金两种试件的拉伸试验,将测量结果与传统的应变片应变测量方法进行对比。研究结果表明:该方法可以准确地完成像点在多相机视频引伸计图像中的动态跟踪测量,且相机标定结果的重投影误差小于0.05pixel,两种试件应变的平均误差分别为0.1709%、0.0499%,说明多相机视频引伸计的动态跟踪测量方法基本适用于应变程度较大的应变测量场景。To facilitate dynamic deformation measurement of multi-camera video extensometer images,this study proposes a tracking matching method for large-field-of-view multi-camera video extensometer images.The method,grounded in digital image correlation and object point reprojection theory,is applicable to material strain measurement under large deformations.Firstly,the global calibration of multiple cameras was performed,and the matrix transformation relationship between the camera coordinate system and the world coordinate system was solved for each camera.Secondly,the image points of the sequence images acquired by the video extensometer were traversed and tracked between the camera images of the video extensometer by applying the object point reprojection theory.Finally,the equation of multi-camera video extensometer strain measurement was derived,and a multi-camera video extensometer strain measurement platform was built.The measurement results were compared with the conventional strain gauge strain measurement method through tensile experiments on two specimens of Q235 mild steel and aluminum alloy.The results show that the method accurately completes dynamic tracking measurement of image points in multi-camera video extensometer images,with a camera calibration reprojection error of less than 0.05 pixel and average strain errors of 0.1709%and 0.0499%for the two specimens,respectively.The results show that the dynamic tracking measurement method of multi-camera video elicitor is basically suitable for strain measurement scenarios with large strain.

关 键 词：视频引伸计 数字图像相关 全局标定 物点重投影 动态变形测量 

分 类 号：TH741[机械工程—光学工程]