多相机网络联合约束优化的高精度三维变形全场测量  

High-precision and full-field measurement of 3D deformation based on multi-camera network joint constraint optimization

作　　者：张贵阳[1] 霍炬[2] 杨明[1] 周婞 朱子健 ZHANG Gui-yang;HUO Ju;YANG Ming;ZHOU Xing;ZHU Zi-jian(School of Astronautics,Harbin Institute of Technology,Harbin 150001,China;School of Electrical Engineering and Automation,Harbin Institute of Technology,Harbin 150001,China;Department of CT Physics and Reconstruction,Neusoft Medical Co.,Ltd,Guangzhou 510000,China)

机构地区：[1]哈尔滨工业大学航天学院,黑龙江哈尔滨150001 [2]哈尔滨工业大学电气工程及自动化学院,黑龙江哈尔滨150001 [3]广州东软医疗有限公司C T影像物理与重建研发部,广东广州510000

出　　处：《光学精密工程》2021年第7期1653-1666,共14页Optics and Precision Engineering

基　　金：装备预研航天科技联合基金(No.6141BXXX);国防重点实验室科工局基金(No.2018XXX-24)。

摘　　要：针对细长型和大尺寸试件的全场变形测量问题,本文提出一种基于数字图像相关方法的立体变形测量方法。通过建立多相机网络的联合约束关系,使其中任意两个CCD相机可以绑定为一个整体完成试件的部分测量,并最终将测量结果映射到统一参考坐标系下,从而减小了因直接进行全场测量而导致较大非线性成像畸变的影响,而且能够避免牺牲采集图像的有效空间分辨率。同时,联合约束关系的优化将图像对间立体配准点的搜索限制在对极线附件区域,而不是整幅图像上,从而缩小了搜索空间,提高了搜索速度。此外,通过优化试件与多相机网络之间的位置及姿态参数,进一步提高了散斑点空间三维坐标的重构精度。最后,通过位移和变形测量实验证明了本文方法的有效性,在[0.8 m,0.5 m,0.6 m]的空间范围内,目标的平移测量误差小于0.044 mm;离面位移测量精度优于0.06 mm。能够满足飞行器地面物理仿真试验的应用需求。To realize full-field measurements of the deformation of slender and large specimens,a novel stereo measurement method based on digital image correlation is proposed. By establishing a joint constraint relationship for the multi-camera network,any two CCD cameras can be bound as a whole to complete partial measurements of the specimen for subsequent mapping onto a unified reference coordinate system. Consequently,the influence of large nonlinear imaging distortions caused by rough full-field measurements is diminished,while the effective spatial resolution of the acquired images is maintained. In addition,an optimized joint constraint relationship accurately restricts the search for stereo matching points between image pairs to the epipolar line instead of the entire image,thereby reducing the search space and improving the search speed. Moreover,by optimizing the position and altitude parameters between the specimen and the multi-camera network,the accuracy of the reconstructed three-dimensional coordinates of the speckle space is further improved. Finally,the displacement and deformation measurement experiments illustrate the effectiveness of the proposed strategy. Within the spatial range of[0. 8 m,0. 5 m,0. 6 m],the translation measurement error of the target is less than 0. 044 mm and the out-of-plane displacement measurement accuracy is high(±0. 06 mm),which meets the application requirements of aircraft ground physical simulation tests.

关 键 词：机器视觉 多相机网络 联合约束优化 数字图像相关 变形测量 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]