三维数字图像测量系统稳定性的实验研究  

Experimental Study of the Stability of Three-Dimensional Digital Image Processing System

作　　者：江天云[1] 潘兵[1] 夏勇[2] 吴大方[1] 

机构地区：[1]北京航空航天大学固体力学所,北京100191 [2]清华大学汽车工程系,北京100084

出　　处：《实验力学》2014年第6期703-710,共8页Journal of Experimental Mechanics

基　　金：国家自然科学基金(11172026;11322220;91216301);教育部新世纪优秀人才计划(NCET-12-0023);清华大学汽车安全与节能国家重点实验室开放基金(KF14032);北京市科技新星计划(xx2014B034)资助的课题

摘　　要：基于双目立体视觉原理的三维数字图像相关方法已被广泛应用于平面或曲面物体的表面形貌和三维变形测量。然而因相机自热、环境温度变化等内外部因素的影响,同一三维数字图像相关测量系统在不同时间,其内部参数会不可避免地发生微小改变,从而或多或少地引起额外的形貌和变形测量误差。为获得高精度的测量结果,需对由相机自热或环境温度变化引起的变形测量误差进行表征,并采用措施予以减小或消除此类误差。本文以石英玻璃平板为研究对象,利用三维数字图像相关测量系统对其位移和应变分布进行了连续5小时的测量,分析了测量结果随相机温度变化的关系曲线。研究结果显示,本文所用相机通电后其机壳温度一般约上升8-10℃甚至更高,所搭建的三维数字图像相关测量系统因相机温度变化所引起的应变测量误差在50-200με（约15-21με/℃）之间。本文还给出了相应建议来减小和消除相机或环境温度变化对三维变形测量的影响。Three-dimensional digital image correlation（3D-DIC）method based on the principle of binocular stereo vision has been extensively used for flat or curved surface topography and threedimensional object deformation measurement.However,the intrinsic parameters of a 3D-DIC system may inevitably change slightly during measurement due to the ambient environment temperature variation and/or digital camera self-heating,which may induce more or less additional error in shape and deformation measurement.In order to obtain accurate measurement results,it is needed first to characterize deformation measurement error due to the ambient environment temperature variation and/or digital camera self-heating,then,adopt measures to reduce or eliminate such error.In this paper,an optical quartz glass plate was used as reference sample.Its displacement and strain distributions were continuously measured at set intervals for 5hours by using a home-made 3D-DIC system.The curve relating measurement results with the variation of temperature was analyzed.Results show that after camera is powered,its case temperature generally rises about 8-10℃ or even higher,the strain measurement error of the 3D-DIC system is within a range of 50-200 microstrain（15-21με/℃）.Some simple but effective suggestions that can effectively eliminate these errors are also proposed in this paper.

关 键 词：三维数字图像测量系统 相机自热 测量误差 

分 类 号：O34[理学—固体力学]