基于三维数字图像相关的三维形貌拼接研究

Study on Mosaic of Three-Dimensional Profile Based on Three-Dimensional DIC

三维数字图像相关(DIC)方法已在众多工程技术领域中得到了日益广泛的应用。当该方法用来测试表面曲率较大的物体的变形时,受双相机之间夹角的限制,不能实现全场的三维形貌测量。采用在两个(及以上)不同位置拍摄,分别得到被测物的局部形貌,然后用三维DIC算法计算局部坐标系之间的坐标变换关系,将局部形貌转换至同一坐标系下并拼接得到被测物全场三维形貌。实验结果验证了该方法的可行性和可靠性。

Three-dimensional （3D） digital image correlation （DIC） has been widely utilized in many engineering technology fields. However, restricted by the angle between two cameras, 3D DIC is not capable of full-field measurement of 3D profile, when objects with large surface curvature are tested. Two local 3D profile of object was obtained when captured in two different locations （and more）. Then the coordi- nate transformation between the two local coordinate systems can be acquired with 3D DIC algorithm. Fi- nally, the full-field 3D profile of object will be obtained when coordinate transformation from local coordi- nate system to the global coordinate system and profile mosaic are implemented. Experimental results have been performed to validate the feasibility and reliability of the proposed method.