数字散斑相关技术最优光照条件研究  

Investigation of the Optimal Light Condition on Digital Image Correlation Method

作　　者：于之靖[1] 陶洪伟[1] 

机构地区：[1]中国民航大学航空地面特种设备科研基地,天津300300

出　　处：《激光与光电子学进展》2014年第10期83-89,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金委员会与中国民用航空局联合项目(U1333105);中央高校基本科研业务费(3122013D019)

摘　　要：研究了光照条件对数字散斑相关技术(DSCM)测量精度的影响,获得了数字散斑相关计算最优的取值参数及光照条件。通过分析DSCM测量理论模型,获得误差与空间频率和平均灰度梯度的关系式,通过计算机模拟数字散斑图像,确定了最优散斑尺寸、最佳拟合窗口和计算窗口。实物实验中引入GSI编码技术,精确地标定了刚体位移,并对不同光照条件下的DSCM测量结果进行了误差分析,结果表明散斑图像的空间频率和平均灰度梯度与光照条件成规律性变化,并与理论分析结果一致。研究结果表明,DSCM测量的最优光照强度为8000 lx,此时图像平均灰度梯度高,DSCM测量精度高。The effect of lighting conditions on digital speckle correlation method （DSCM） measurement accuracy is researched, and the optimal parameters and light condition for digital speckle correlation calculation are obtained. Through theoretical analysis of the model of DSCM, the relational expression of error about the frequency and average gray gradient is obtained. The optimal digital speckles size, fitting window size and calculation window size are got with computer simulation of digital speckle image. Leading into the technology of GSI in physical experiment, the accurate displacement is got and the error of different light conditions is analyzed, finding the connection about light with the frequency and average gray gradient through studying the digital speckle images. Experiments show that 8000 lx is the optimal light condition in DSCM, when average gray gradient is high and DSCM measurement is precision.

关 键 词：测量 数字散斑相关法 光照条件 平均灰度梯度 误差分析 

分 类 号：O348.1[理学—固体力学]