数字图像相关方法最优散斑尺寸  

Optimal Size of Speckle Spot in Digital Image Correlation Method

作　　者：王志勇[1] 王磊[1] 郭伟[1] 沈珉[1] 

机构地区：[1]天津大学机械工程学院,天津300072

出　　处：《天津大学学报》2010年第8期674-678,共5页Journal of Tianjin University(Science and Technology)

基　　金：国家重点基础研究发展计划(973计划)资助项目(2007CB714002);国家自然科学基金资助项目(10972155)

摘　　要：综合分析了图像灰度噪声和亚像素插值误差这两种最主要的误差源对数字图像相关方法位移测量精度的影响,并在此基础上建立了计算数字图像相关方法的总测量误差数学模型.在综合考虑这两种误差的基础上具体分析了散斑尺寸对数字图像相关方法的位移测量精度的影响,运用理论分析和数值模拟得到了不同参数下的最优散斑尺寸.研究结果表明,对于一定的测量参数而言,存在一个散斑尺寸的最优区间,在这个区间内的散斑越多,数字图像相关方法的位移测量精度越高.The effects of two key error sources,intensity error and sub-pixel interpolation error,on the displacement error of digital image correlation（DIC） were investigated.A theoretical model was presented to calculate the total measurement error of DIC.The effects of the size of speckle spots on the measurement precision of DIC were studied when considering these two error sources,and the optimized size of speckle spots was obtained through theoretical analysis and numerical simulation.The results indicated that there is an optimized interval for speckle spot size.The more speckle spots there exist in the interval,the higher accuracy can be achieved by DIC.

关 键 词：数字图像相关方法 位移测量精度 随机噪声 插值误差 

分 类 号：O348.1[理学—固体力学]