摘要
针对普通单相机数字图像相关(DIC)系统仅能测量目标面内变形信息的问题,本文提出了一种采用单相机DIC系统实现三维全景测量的方法,即:根据多平面镜成像原理,被测目标的前后表面成像在一个共同的视场内,两个光路分别成像在两个平面镜中,将单相机扩展为4台虚拟相机,实现三维全景测量。为了更好地完成虚实像转换,实验之前对平面镜表面进行三维重建,分别采用动态、静态实验对该方法的可行性及精度进行验证。结果表明:在动态拉伸测试中,4个子区域有着相近的变化趋势,工程应变普遍分布在0.0125左右,且位移精度较高;在静态实验中,对决策币的前后表面进行三维重建,重建结果与决策币形貌相吻合。
Objective The conventional single-camera digital-image correlation(DIC)system can only measure the in-plane deformation information of the measured object.2D-related information cannot meet the need for high-precision measurements owing to a continuous improvement in measurement requirements.A common DIC measurement method is to use a binocular or multicamera DIC system.The binocular DIC system can obtain the measured object's in-plane and out-of-plane deformation information,as well as 3D coordinates for stereo reconstruction.Owing to the limited field-of-view of the binocular system,it can only measure a part of the surface,and the conventional binocular DIC system does not have the capability of panoramic measurement.The multicamera DIC system can realize the panoramic deformation measurement under multiple viewpoints.However,the multicamera system increases the system’s size and makes the calibration process difficult.Further,it results in high application costs,which has a significant impact on the use of the multicamera DIC system.Therefore,a 3D panoramic measurement solution that is easy to use,simple to calibrate,and low in application cost is required.Methods This paper proposed a mirror-assisted single-camera DIC system to realize 3D panoramic measurement,and the principles of plane mirror imaging and conversion of virtual and real images were derived.The single-camera DIC system utilized the imaging principle of multiplane mirrors with the assistance of six plane mirrors,allowing the front and rear surfaces of the measured object to be imaged in a common field-of-view.The left and right optical paths were imaged simultaneously,and each optical path contained two images of the front and back surfaces of the measured object.Consequently,this method divided a single camera into four virtual cameras,achieving the necessary conditions for 3D panoramic-related measurement.To better complete the conversion of virtual and real images,the projected speckle pattern was used to perform 3D reconstruction on the
作者
葛朋祥
王欢庆
朱奕磊
王永红
Ge Pengxiang;Wang Huanqing;ZhuYilei;Wang Yonghong(School of Instrument Science and Optoelectronics Engineering,Hefei University of Technology,Hefei 230009,Anhui,China;Anhui Province Key Laboratory of Measuring Theory and Precision Instrument,Hefei University of Technology,Anhui 230009,Hefei,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2022年第9期61-69,共9页
Chinese Journal of Lasers
基金
国家重点研发计划(2016YFF0101803)
合肥市自然科学基金(2021017)。
关键词
测量
数字图像相关
单相机
平面镜成像
全景测量
measurement
digital image correlation
single camera
plane mirror imaging
panoramic measurement
