二维多相机全场数字图像相关变形测量方法  

Deformation Measurement by Two-Dimensional Multi-Camera Full-Field Digital Image Correlation

作　　者：刘聪[1] 戴云彤[1] 戴美玲[1] 刘晓鹏[2] 朱程鹏[1] 邵新星 何小元[1] 

机构地区：[1]东南大学江苏省工程力学分析重点实验室,江苏南京210096 [2]中国海洋大学信息科学与工程学院,山东青岛266100

出　　处：《光学学报》2016年第12期97-105,共9页Acta Optica Sinica

基　　金：国家自然科学基金(11272089;11327201;11532005;11602056);国家科技支撑计划(2014BAK11B04);普通高校研究生科研创新计划(KYLX_0091);东南大学优秀博士学位论文培育基金(YBJJ1509);中央高校基本科研业务费专项资金

摘　　要：从理论上推导了数字图像相关(DIC)方法中应变精度的影响因素,指出应变计算精度会随着窗口尺寸的变小而下降。为了提高图像有效分辨率,针对细长平面试件提出了一种二维多相机全场DIC方法。该方法根据特征点检测及匹配算法定位特征点对的亚像素位置,通过DIC方法对特征点对进行高精度配准,利用发展的逐步优化单应矩阵方法求解图像变换关系,得到变形前后的无缝拼接图像。分别实施了纯平移和橡胶梁三点弯两组实验。在纯平移实验中,该方法计算得到的应变均值误差及均方根误差均在50με以内,验证了该方法的有效性;采用橡胶梁三点弯实验对比该方法与三维多相机全场DIC方法,并基于实验结果对该方法的优点与缺点进行了分析。The factors impacting strain precision in the digital image correlation（DIC）method is derived theoretically.It is pointed out that the precision of strain calculation will decrease as the calculation window gets small.In order to improve the effective image resolution,a novel perspective to two-dimensional multi-camera full-field DIC method is proposed for slender specimen.The sub-pixel position of matching feature point pairs is found based on feature point detection and matching algorithm.The matching feature point pairs are registered with high precision using the DIC method.Finally,agradually optimized homography solution method is developed to solve the image transformation to get the seamless stitched images before and after deformation.Two sets of experiments including pure translation and three-point bending of rubber beam are conducted.In the pure translation experiments,the mean error and root-mean-square error of calculated strain are within50με,which verifies the validity of this method.Twodimensional and three-dimensional multi-camera DIC methods are compared through the three-point bending experiments.Based on the results,merits and demerits of the proposed method are discussed.

关 键 词：测量 二维数字图像相关 多相机 全场变形 图像拼接 

分 类 号：O348.1[理学—固体力学]