Accurate and fast in-plane displacement measurement method for large-scale structures by utilizing repeated pattern
Accurate and fast in-plane displacement measurement method for large-scale structures by utilizing repeated pattern
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DOI：
10.1117/12.2008286
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发表时间：
2013-04
期刊：
影响因子：
--
通讯作者：
S. Ri;S. Hayashi;S. Ogihara;H. Tsuda
中科院分区：
文献类型：
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作者：
S. Ri;S. Hayashi;S. Ogihara;H. Tsuda
基于成像的无损监测系统对于评估大型基础设施至关重要。本研究开发了一种基于成像技术的精确、快速的面内位移测量方法，用于高层建筑、长桥等大型基础设施的健康监测。利用基础设施立面上内置的重复图案，如瓷砖、格子、砖墙图案来精确测量面内位移分布。通过对变形前后拍摄的图像进行下采样和强度插值图像处理，可以同时获得多个相移莫尔条纹。使用相移法和离散傅立叶变换技术计算莫尔条纹的相位分布。在本研究中，基频和高频分量都被考虑来分析重复模式。根据变形前后莫尔条纹的相位差可以得到面内位移分布。与传统的位移方法和传感器相比，本文开发的方法的主要优点是高分辨率、准确、快速、低成本且易于实现。提出了所提出的面内位移测量的原理。通过简单的位移测量实验证实了我们方法的有效性。实验结果表明，在米级视场范围内可以成功检测到亚毫米级位移。
Imaging based nondestructive monitoring systems are critical for evaluation of large-scale infrastructures. In this study, an accurate and fast in-plane displacement measurement method based imaging technique is developed for the purpose of health monitoring of large-scale infrastructures such as high building, long bridge, etc. The build-in repeated patterns on infrastructure facade, such as tile, checker, and brick wall pattern is used to measure the in-plane displacement distribution accurately. By performing down-sampling and intensity interpolation image processing to the images captured before and after deformations, multiple phase-shifted moiré fringe can be obtained simultaneously. The phase distribution of the moiré fringe is calculated using the phase shifting method and discrete Fourier transform technique. In the present study, both the fundamental and high frequency components are considered to analyze the repeated patterns. The in-plane displacement distribution can be obtained from the phase differences of the moiré fringe before and after deformations. Compared with conventional displacement methods and sensors, the main advantages of the method developed herein are high-resolution, accurate, fast, low-cost, and easy to implement. The principle of the proposed inplane displacement measurement is presented. The effectiveness of our method is confirmed by a simple displacement measurement experiment. Experimental result showed that a sub-millimeter displacement could be successfully detected for the field of view with meter-scale.