基于图像相关的结构变形全过程测量方法

发布时间：2018-05-09 05:28

本文选题：数字图像相关 + 结构变形　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：针对土木工程结构大变形全过程非接触测量的需求,本文提出基于图像相关的结构变形全过程测量方法。本文将张正友标定方法引入传统DIC方法,介绍了应用单目相机测量结构变形的方法。针对桥梁挠度长期监测的需求,本文提出基于CCD的桥梁挠度测量方法。针对已有的双目立体视觉测量方法,本文对提高其计算精度的方法进行了研究。在以上研究的基础上进行了试验研究。本文的主要内容包括:(1)提出基于张正友标定的DIC方法。传统DIC方法中未考虑镜头畸变,影响计算精度;同时,该方法为了将像素单位转换为实际长度单位毫米,需要在被测试件表面粘贴长度已知的标尺,操作不便。本文将张正友标定方法引入传统DIC方法,形成基于张正友标定的DIC方法,不仅可以提高计算精度,还可以避免粘贴标尺,简化试验操作。本文通过平动台水平平移位移测量试验对该方法进行验证。(2)针对桥梁挠度长期监测的需求,本文提出基于CCD的桥梁挠度测量方法。在桥梁跨中安装用于跟踪的特制靶标,用CCD记录包含有靶标的图像,应用DIC方法跟踪靶标在视场中位置的变化从而计算出桥梁的挠度。针对宋家庄公铁立交桥挠度监测的具体要求,本文集成宋家庄公铁立交桥挠度测量系统。现场返回的数据表明,该系统工作状态良好,本文方法可以满足桥梁挠度长期监测的需求。(3)提高双目立体视觉测量精度的改进研究。在初始时刻立体匹配和时序匹配的过程中,本文提出根据极线约束修正匹配结果——用满足极线约束的距离原匹配结果最近的点代替原匹配结果。提出应用SUSAN滤波方法处理采集得到的数据图像。比较亚像素定位中的二次曲面拟合方法和三次曲面拟合方法。提出将计算得到的位移场投影到初始时刻拟合到的平面上的两个正交向量上。比较应变计算中的局部最小二乘多项式拟合方法和有限单元法。(4)完成系统零漂试验、CFRP混凝土界面黏结滑移测量试验和大跨越输电导线模型风洞试验。静置被测试件,应用本文方法测量测点零漂值,得出在95%概率统计下,本文系统及方法的计算精度约为0.006mm。应用本文方法计算CFRP混凝土界面黏结滑移试验中的整体位移,并与位移计数据进行对比,结果表明本文方法测得的位移曲线与位移计曲线吻合较好,验证本文方法的可靠性与实用性;应用本文方法计算得到CFRP混凝土界面破坏时的滑移量。应用本文方法计算大跨越输电导线模型在不同风速下的面外位移。
[Abstract]:In order to meet the requirement of non-contact measurement for large deformation of civil engineering structures, a method based on image correlation is proposed in this paper. In this paper, the calibration method of Zhang Zhengyou is introduced into the traditional DIC method, and the method of measuring the deformation of the structure with a monocular camera is introduced. In order to meet the need of long-term monitoring of bridge deflection, this paper presents a bridge deflection measurement method based on CCD. Aiming at the existing binocular stereo vision measurement methods, this paper studies the methods to improve the calculation accuracy. On the basis of the above research, an experimental study was carried out. The main contents of this paper include: 1) A DIC method based on Zhang Zhengyou calibration is proposed. The traditional DIC method does not take lens distortion into account, which affects the accuracy of the calculation. In order to convert pixel units into actual length units, the traditional DIC method needs to paste a ruler with known length on the surface of the tested piece, which is difficult to operate. In this paper, the Zhang Zhengyou calibration method is introduced into the traditional DIC method to form the DIC method based on Zhang Zhengyou calibration, which can not only improve the calculation accuracy, but also avoid sticking the ruler and simplify the test operation. In this paper, the method is verified by horizontal displacement measurement test. (2) in order to meet the need of long-term monitoring of bridge deflection, a bridge deflection measurement method based on CCD is proposed in this paper. A special target for tracking is installed in the span of the bridge. The images containing the target are recorded by CCD and the deflection of the bridge is calculated by tracking the position of the target in the field of view by using the DIC method. According to the specific requirements of deflection monitoring of Songjiazhuang railway overpass, the deflection measurement system of Songjiazhuang railway overpass is integrated in this paper. The data returned from the field show that the system is in good working condition, and the method in this paper can meet the need of long-term monitoring of bridge deflection, and improve the precision of binocular stereoscopic vision measurement. In the process of initial time stereo matching and time series matching, this paper proposes to modify the matching result according to the pole line constraint-to replace the original matching result with the point that satisfies the pole line constraint and is closest to the original matching result. A method of SUSAN filtering is proposed to process the collected data images. The conic surface fitting method and the cubic surface fitting method in sub pixel location are compared. The calculated displacement field is projected to two orthogonal vectors on the plane fitted to the initial moment. The local least square polynomial fitting method and finite element method are used to complete the system zero drift test and the test of CFRP concrete interface bond slip and the wind tunnel test of long span transmission line model. The zero drift value of the measured point is measured by using the method in this paper, and the calculation accuracy of the system and the method is about 0.006 mm. under 95% probability statistics. The whole displacement of CFRP concrete interface bond slip test is calculated by using this method, and compared with the data of displacement meter. The results show that the displacement curve measured by this method is in good agreement with the displacement gauge curve. The reliability and practicability of this method are verified, and the slip amount of CFRP concrete interface failure is calculated by using this method. In this paper, the out-of-plane displacement of long span transmission line model under different wind speeds is calculated by using this method.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU317;TP391.41

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