共查询到17条相似文献,搜索用时 125 毫秒
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提出一种利用深度学习提取散斑变形图像位移场的算法。对比几种主流光流网络模型在散斑图像上的计算精度,将全局运动聚合(GMA)光流网络引入数字图像相关法,使用光流网络模型预测的位移场作为亚像素迭代算法的初值,最后结合逆合成高斯-牛顿法计算散斑图像的亚像素位移场。结果表明,与几种主流的数字图像相关算法相比,GMA光流网络初值的计算精度和计算效率更高,适用于大变形测量,是一种兼顾计算速度和精度的变形测量算法。对木块材料进行压缩实验,结果充分显示了所提方法在散斑变形测量中的有效性。 相似文献
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与传统测量方法相比,数字散斑相关法由于其目标特征单元网格划分的灵活性,能够更好地满足不同场合小角位移的测量需求。针对该方法亚像素小角位移测量的曲面拟合参数选择问题,研究了亚像素测量图像小角旋转前后的九点二次曲面拟合法,并根据计算机生成模拟散斑进行模拟实验分析,得到最佳误差效率优化条件下的曲面拟合法求解亚像素小角位移的最佳散斑尺寸3.5 pixel、计算窗口尺寸41×41 pixel和拟合窗口尺寸3×3 pixel。实验验证了上述测量参数的有效性,为进一步的曲面拟合法数字散斑成像角位移测量提供参考。 相似文献
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数字散斑相关方法有着测量环境简单、全场非接触等优点,但算法效率一直是限制其发展的瓶颈之一。GPU有着天然的并行性,GPU高性能运算可以为计算机图形处理带来极大的效率提升。利用CUDA平台编程对传统的数字散斑逐点搜索算法、十字搜索算法及遗传算法进行GPU高性能并行处理,并与传统方法比较分析。实验结果表明,对于尺寸为150150像素的散斑图像,3种方法效率分别提升了20倍、8倍、31倍;对于尺寸为500500像素的散斑图像,3种方法效率分别提升了183倍、33倍、44倍;对于尺寸为1 0001 000像素的散斑图像,3种方法效率分别提升了424倍、116倍、44倍。 相似文献
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数字散斑相关方法实现鼠标定位原理 总被引:2,自引:1,他引:1
在激光鼠标工作原理的基础上,利用数字散斑相关方法对激光鼠标的定位原理进行了研究。设计实验得到散斑场并用数码相机拍摄。用图像采集卡采集CCD扫描数散斑图像得到的图像,将图像数字化,分析数据得到了图像最优采样的像素单元和图像位移两个参量。基于两个参量,实验采集散斑图像在一定的轨迹运动下的散斑场,用Matlab软件模拟,并比较分析了实验和模拟结果。结果表明,用数字散斑相关方法可以实现激光鼠标的定位功能,并且分辨力可达到1μm,远高于市场上激光鼠标30μm的分辨力。 相似文献
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采用离面位移测量精度达到10 nm~20 nm的电子散斑干涉测量系统验证了双目视觉数字散斑相关测量系统的离面位移测量精度。分别用电子散斑干涉测量系统和双目视觉数字散斑相关测量系统同时测量了平板离面位移,并对所测量的位移最大值进行了分析处理及比较。结果表明,双目视觉数字散斑相关测量系统的物体离面位移分布云图与电子散斑干涉测量系统的结果基本相同,且两者位移均方根相差为2.76 m~3.56 m,相对误差为4.59%~7.60%。因此,当被测量物体的离面位移大于4 m时,双目视觉Q400测量系统精度可达到电子散斑干涉测量系统的精度。 相似文献
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数字散斑相关方法及应用进展 总被引:1,自引:0,他引:1
数字散斑相关方法(DSCM)是一种可以测量变形和应变的光学非接触测量方法,其通过对变形前后物体表面的图像进行灰度信息相关计算来获取被测物的力学性能。本文叙述了数字散斑相关方法近年来在国内外的发展动态和应用现状,详细论述了基于自适应遗传算法、智能神经网络方法、小波变换法的一系列新型相关搜索方法。文章指出,近年来,数字散斑相关技术已发展到相对成熟,目前的研究重点是提高测试精度和图像处理速度,而提高散斑图像质量和研究高效的算法是需要努力的方向。 相似文献
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Application of an improved subpixel registration algorithm on digital speckle correlation measurement 总被引:2,自引:0,他引:2
Digital speckle correlation method (DSCM) has been widely used in experimental mechanics to obtain the surface deformation fields. One of the challenges in practical applications is how to obtain the high accuracy with far less computation complexity. To determine the subpixel registration of the DSCM, a high efficient gradient-based algorithm is developed in this paper. The principle is described and four different modes of the algorithm are given. Based on computer-simulated images, the optimal mode of the algorithm is verified through the comparison of computation time, optimal subset-region size and sensitivity of the four modes. The influences of speckle-granule size and speckle-granule density on accuracy are studied and a quantitative estimation of the optimal speckle-granule size range is obtained. As the applications of this method, the practical deformation measurements with the rigid body translation and rotation as well as an experiment on biomechanics are presented to certify the feasibility and the validity of the algorithm. 相似文献
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采用半圆盘弯曲实验和数字散斑相关方法,对高聚物粘结炸药(PBX)的宏、细观断裂行为进行了实验研究。宏观上,带有预制裂纹的半圆盘试样发生拉伸破坏,利用数字散斑相关技术得到了试样的应变场和位移矢量场分布,定量分析了试样全场的变形特征,并测得了PBX材料的平面应变断裂韧性;细观上,用配有加载装置的扫描电子显微镜对含预制裂纹的半圆盘试样间接拉伸下的损伤演化和破坏过程进行了实时原位观察,借助于数字散斑相关方法,定量分析了试样损伤局部化特征。结果表明,将数字散斑相关方法用于研究PBX材料宏、细观尺度上的变形破坏问题是有效的。 相似文献
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In the strain field measurements, especially in large strain field measurements, the correlation coefficient values obtained by the digital speckle correlation method are usually very low due to the relative pixel movement of the subset. The measuring error, therefore, is increased. A primary method, that is called compensation algorithm, is introduced for improving the correlation coefficient. A flow scheme with the compensation algorithm of our software is developed and some improved techniques for reducing the calculation time and error are discussed in the paper. After obtaining a set of displacement data with high correlation coefficient, a de-noise wavelet processing is adopted. It is obvious that the measuring accuracy of the strain field is better then before. A strain field of testing experiment is performed with this compensation technique. The correlation coefficients can increase from 0.70 to 0.99, which will be of much benefit for the improvements of the measuring accuracy. 相似文献
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Evaluating the accuracy performance of Lucas-Kanade algorithm in the circumstance of PIV application
《中国科学:物理学 力学 天文学(英文版)》2015,(10)
Lucas-Kanade(LK) algorithm, usually used in optical flow filed, has recently received increasing attention from PIV community due to its advanced calculation efficiency by GPU acceleration. Although applications of this algorithm are continuously emerging,a systematic performance evaluation is still lacking. This forms the primary aim of the present work. Three warping schemes in the family of LK algorithm: forward/inverse/symmetric warping, are evaluated in a prototype flow of a hierarchy of multiple two-dimensional vortices. Second-order Newton descent is also considered here. The accuracy efficiency of all these LK variants are investigated under a large domain of various influential parameters. It is found that the constant displacement constraint, which is a necessary building block for GPU acceleration, is the most critical issue in affecting LK algorithm's accuracy, which can be somehow ameliorated by using second-order Newton descent. Moreover, symmetric warping outbids the other two warping schemes in accuracy level, robustness to noise, convergence speed and tolerance to displacement gradient, and might be the first choice when applying LK algorithm to PIV measurement. 相似文献