基于条纹频率的无包络三维变形测量技术研究

发布时间：2018-05-20 14:21

本文选题：形变测量 + 条纹频率　；参考：《山东师范大学》2017年博士论文

【摘要】：光学干涉计量技术在我国的许多领域都有着十分重要的应用。随着近年来科技的发展,各个行业的研究人员对测量方面的需求也在不断提高。因此,寻找一种实用性强、操作简单、精度较高的测量方法对于各个领域的科学研究工作来说意义重大。本文介绍了一种新型的三维变形测量技术,可以由两幅光干涉条纹图实现全场的三维位移测量。该方法是基于图像一致性假设与光流基本方程而提出的,首先由窗口傅里叶脊法提取了初始图像的条纹频率,由光流法获得了变形前后图像的面内位移场,然后根据光流基本方程将条纹频率、面内位移场与离面变形相位三者建立了数学关系,实现了由面内位移来得到离面变形相位的计算过程。然而由于光流算法本身的限制,该方法在图像边缘处与中心处所获得的数据误差较大。为了解决这一问题,我们运用数字图像相关法替代光流法完成了面内位移的测量工作,以实现更精确的三维位移测量。文章介绍了电子散斑干涉术、窗口傅里叶脊法、光流法及数字图像相关法的原理,对平面加载的圆盘与周边固定、中心加载的圆盘分别进行了计算机模拟与典型实验。模拟结果与实验结果均表明,该方法能够根据直观的面内位移场解调出物体全场离面位移信息。该方法优点与创新之处在于操作过程简单方便,能同时提取变形物体的三维位移场,既不需要将条纹图像转换到频域,也不需要相位解包络运算,且在条纹越密集处提取的离面变形相位信息更准确。由于该方法仅需要两幅图像便可完成物体三维形变的测量工作,所以该算法为全场三维动态测量提供了新的思路。除此之外,文章在最后介绍了两种最近刚被提出的变形测量技术:载频交叠重构干涉术与基于二维连续小波变换的散斑相位奇异法。这两种方法均具能有效地抑制环境噪声,获得更精确的测量结果。本文将这两种方法分别应用于电子散斑干涉术与光干涉图像当中,对这两种方法在三维形变测量方面的应用前景做了研究与预测。本文的主要章节研究内容如下:第一章主要对物体三维面形与变形测量的研究现状进行了综合性的论述,介绍了包裹相位与相位解包络操作的概念与无包络三维测量的研究意义。第二章首先介绍了电子散斑干涉术术(ESPI)的基本原理。由于在运用ESPI计算离面位移时需要先提取离面变形相位的信息,所以又介绍了两种相位提取方法:相移法与傅里叶变换法。其中,相移法的测量精度较高,但是其需要的图像也比较多,不适合于动态测量;傅里叶变换法只需要一幅图像便可完成相位的提取,但是与相移法相比测量精度较低且不适用于闭合条纹图的测量工作。除此之外,这两种方法都需要用到相位解包络操作,这无疑增加了位移计算的误差。在后文中提到的基于光流法的三维位移测量技术、基于图像相关的三维位移测量技术、载频交叠重构散斑干涉测量技术与基于小波变换的相位奇异网格法的思路都是在ESPI原理的启发下获得的。第三章主要介绍了运用窗口傅里叶脊提取图像条纹频率的基本原理。这一章首先定义了条纹频率与窗口傅里叶变换的概念,然后针对现有的窗口傅里叶脊算法的不足对其进行了改进。模拟实验结果表明改进后的窗口傅里叶脊算法提取的条纹频率的精度更高,适用性更加广泛。本章中提取的图像条纹频率在后文当中有重要应用。第四章从光流场的概念与光流算法的研究现状入手,对光流法测量物体三维形变的基本原理展开了论述。该算法将初始图像的条纹频率、变形前后图像的面内位移场与离面变形相位三者建立了直接的联系,实现了由直观的面内位移场测量离面位移的运算过程。模拟结果与实验均表明该算法可以实现三维位移的测量。针对光流法具有边缘效应这一缺陷,第五章提出用数字图像相关法来替代光流法以改进第四章中提出的三维位移测量方法。这一章首先论述了基于梯度法的数字图像相关亚像素算法的基本原理与研究现状,然后将该方法与光流法结合后测量了周边固定、中心加载圆盘的三维形变量。模拟结果与实验结果均表明该方法的测量精度比改进前的光流法的精度更高,测量范围更广。第六章主要探讨了载频交叠重构干涉术(CSI)与基于二维连续小波变换(CWT)的散斑相位奇异法在散斑干涉计量与光干涉计量当中应用。CSI算法是一种可以将环境噪声与图像中有用的信息直接分离的测量技术。经实验验证,该方法可以将散斑干涉条纹图像的有效频谱与噪声频谱分离,可应用于散斑干涉计量当中。基于二维CWT的相位奇异网格法是一种测量面内位移的方法。本文将此方法与光流法相结合,先测量了平动图像之间的面内位移,证明了该方法对面内位移测量的有效性与鲁棒性,然后对结合后的算法在离面微位移测量方面的前景进行了探讨。第七章总结了文章的主要成果与创新点,并简单论述了下一步的研究工作。
[Abstract]:Optical interferometry has a very important application in many fields of our country. With the development of science and technology in recent years, the needs of researchers in various industries are increasing. Therefore, to find a practical, simple and high precision measurement method for the scientific research work in various fields. It is of great significance. This paper introduces a new three-dimensional deformation measurement technique, which can be measured by two optical interference fringes. This method is based on the assumption of image consistency and the basic equation of optical flow. First, the fringes frequency of the initial image is extracted by the window Fourier ridge method, and the change of the frequency is obtained by the optical flow method. The in-plane displacement field of the image before and after the shape is obtained, then the relationship between the frequency of the stripe, the displacement field of the plane and the phase of the deformed deformation is established according to the basic equation of the light flow, and the calculation process of the phase of the deformed deformation is achieved by the in-plane displacement. However, because of the limitation of the optical flow algorithm itself, the method is obtained at the edge of the image and the center. In order to solve this problem, in order to solve this problem, we use the digital image correlation method to replace the optical flow method to complete the measurement of the in-plane displacement to achieve more accurate three-dimensional displacement measurement. This paper introduces the principle of electronic speckle interferometry, window Fu Liye ridge method, optical flow method and digital image correlation method, and the plane loaded disk. The simulation results and experimental results show that the method can demodulate the full field off plane displacement information according to the intuitionistic in-plane displacement field. The advantage and innovation of this method is that the operation is simple and convenient, and can extract three deformed objects at the same time. The dimensional displacement field does not need to convert the stripe image to the frequency domain, nor does it need the phase envelope operation, and the phase information of the deformed phase is more accurate. As the method only needs two images, it can measure the three-dimensional deformation of the object, so the algorithm provides a new thought for the full field three-dimensional dynamic measurement. In addition, the paper finally introduces two recently proposed deformation measurement techniques: carrier overlapping reconstruction interferometry and speckle phase singular method based on two-dimensional continuous wavelet transform. These two methods can effectively suppress environmental noise and obtain more accurate measurement results. These two methods are applied to electricity respectively in this paper. The application prospects of these two methods in 3D deformation measurement are studied and predicted. The main chapters of this paper are as follows: the first chapter is a comprehensive exposition of the research status of the measurement of three-dimensional shape and deformation of objects, and the envelope phase and the phase solution envelope. In the second chapter, the basic principle of electronic speckle interferometry (ESPI) is introduced. In this chapter, two phase extraction methods, phase shift method and Fu Liye transform method, are introduced because of the need to extract the information of the deformed phase when using ESPI to calculate the displaced displacement. The accuracy of the measurement is high, but it needs more images, and it is not suitable for dynamic measurement. The Fu Liye transform method only needs one image to complete the phase extraction, but compared with the phase shift method, the measurement accuracy is low and does not apply to the measurement of the closed fringe pattern. In addition, these two methods need to use the phase solution envelope. Operation, this undoubtedly increases the error of displacement calculation. In the latter part, the three-dimensional displacement measurement technology based on the optical flow method, based on the three-dimensional displacement measurement technology based on the image correlation, the thought of the carrier frequency overlapping reconstruction speckle interferometry and the phase singular grid method based on the wavelet transform are both inspired by the ESPI principle. The three chapter mainly introduces the basic principle of using window Fourier ridge to extract the frequency of image stripe. This chapter first defines the concept of fringe frequency and window Fourier transform, and then improves the existing window Fourier ridge algorithm. The simulation experiment results show that the improved window Fourier ridge algorithm is extracted. The frequency of stripe is more accurate and more applicable. The frequency of image stripe extracted in this chapter has an important application in the latter part. The fourth chapter starts with the concept of optical flow field and the research status of optical flow algorithm, and discusses the basic principle of measuring three-dimensional deformation of objects by optical flow method. The algorithm changes the frequency of the stripe of the initial image. The in-plane displacement field in the front and back image is directly connected with the phase of the deformed phase three. The calculation process of measuring the displaced displacement by an intuitionistic displacement field is realized. The simulation results and experiments show that the algorithm can measure the three-dimensional displacement. The fifth chapter puts forward the number of figures for the edge effect of the optical flow method. The image correlation method is used to replace the optical flow method to improve the three-dimensional displacement measurement method proposed in the fourth chapter. This chapter first discusses the basic principle and research status of the digital image correlation sub-pixel algorithm based on the gradient method. Then, the method is combined with the optical flow method to measure the surrounding fixed, the three-dimensional shape variables of the central loading disk. The results and experimental results show that the accuracy of the method is higher than that of the improved optical flow method, and the range of measurement is more extensive. The sixth chapter mainly discusses the application of.CSI algorithm in the speckle dry measurement and optical interferometry based on the carrier frequency overlapping reconstruction interferometry (CSI) and the speckle phase singular method based on the two-dimensional continuous wavelet transform (CWT). This method can separate the environmental noise directly from the useful information in the image. It is proved by experiment that this method can separate the effective spectrum of the speckle interference fringes and the noise spectrum, and can be applied to the speckle interferometry. The phase singular grid method based on the two-dimensional CWT is a method for measuring the in-plane displacement. Combined with the optical flow method, the in-plane displacement between the translational images is measured first, and the effectiveness and robustness of the method is proved. Then the prospect of the combined algorithm in the measurement of the off surface micro displacement is discussed. The seventh chapter summarizes the main achievements and innovation points of the article, and briefly discusses the next step. Research work.
【学位授予单位】：山东师范大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O436.1

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