先验知识辅助的条纹投影动态三维形貌测量  

Priori knowledge assisted dynamic 3D shape measurement with fringe projection

作　　者：楚冬娅 张广汇 宋仁杰 张晓松 应晓霖 李勇[1] Chu Dongya;Zhang Guanghui;Song Renjie;Zhang Xiaosong;Ying Xiaolin;Li Yong(Institute of Information Optics,Zhejiang Normal University,Jinhua,Zhejiang 321004,China;Key Laboratory of Optical Information Detecting and Display Technology of Zhejiang Province,Jinhua,Zhejiang 321004,China)

机构地区：[1]浙江师范大学信息光学研究所,浙江金华321004 [2]浙江省光信息检测与显示技术重点实验室,浙江金华321004

出　　处：《光电工程》2022年第8期55-63,共9页Opto-Electronic Engineering

基　　金：浙江省自然科学基金资助项目(LY17F050002)。

摘　　要：为改进条纹投影动态三维测量系统性能,根据动态物体三维形貌测量的特点提出了两步法测量方案:1)通过测量运动前物体或CAD模型,获得物体初始三维形貌及二维图像中特征点对应的三维坐标;2)进行物体运动变化过程的三维测量。通过检测动态图像中的特征点,根据二维、三维坐标对应关系计算物体不同时刻的运动参数,再由初始形貌估计出物体的近似形貌,以此来计算该时刻条纹图的近似相位。然后结合该近似相位及实际条纹的截断相位计算得到展开相位,最后获得该时刻物体的三维形貌。与时间相位展开法相比,该方案在相同测量精度下提高了测量速度;而与空间相位展开法相比,该方案在相同测量速度下提高了测量可靠度,并且不受条纹不连续影响。采用DLP投影仪和高速摄像机搭建了静态、动态双模式三维测量系统,实现了1280×1024点及70 f/s的三维形貌测量。实验结果表明该方案不但可以对刚体运动物体进行测量,而且对非刚体运动物体,只要其形变引起的条纹变化不超过半个周期也能够测量。同时,提出的方法对相邻时刻物体位姿变化有较大的容限。A two-step scheme is proposed to improve the performance of dynamic 3D shape measurement according to its characteristics.1)The initial 3D shape of the object and the corresponding 3D coordinates of feature points in the 2D image are obtained by measuring the static object or its CAD model.2)Carry out the 3D measurement in the process of object motion and change.By detecting the feature points in the dynamic image,the motion parameters of the object at different times are calculated according to the corresponding relationship between two-dimensional and three-dimensional coordinates.Then the approximate shape of the object is estimated from the initial shape.The approximate phase of the fringe pattern at this time is calculated.Then,combined with the approximate phase and the wrapped phase of the actual fringe,the unwrapped phase is calculated,and the 3D shape of the object at that time is obtained.Compared with the temporal phase unwrapping method,the proposed scheme improves the measurement speed under the same measurement reliability.Compared with the spatial phase unwrapping method,this scheme improves the measurement reliability at the same measurement speed and is not affected by fringe discontinuity.A static and dynamic dual-mode 3D measurement system was built by using a DLP projector and high-speed camera.The 3D shape measurement of 1280×1024 points at 70 f/s is realized.The experimental results show that the scheme can measure not only the rigid moving object but also the non-rigid moving object,as long as the fringe change caused by its deformation does not exceed half a period.The proposed method has a large tolerance for the change of object pose at adjacent times as well.

关 键 词：机器视觉 光学三维形貌测量 相位测量轮廓术 相位展开 

分 类 号：TN206[电子电信—物理电子学]