【作者】 王琳霖；

【导师】 唐晨；

【作者基本信息】 天津大学 ， 检测技术与自动化装置， 2012， 博士

【摘要】 光学测量技术是一种全场、非接触无损检测技术，渗透到科学和工程的多个领域。电子散斑干涉技术(ESPI)和数字散斑相关方法(DSCM)是两种最常用的光学测量方法。高精度的信息提取是这两种光学测量技术应用的基础。本文就电子散斑干涉技术和数字散斑相关方法中有关信息提取的一些关键问题进行了研究。电子散斑干涉测量以条纹图或相位图的形式表现测量结果，然而无论是条纹图还是相位图都含有大量的噪声，严重干扰了相位信息的提取。因此，如何有效地降低噪声的影响，提高条纹的对比度，成为电子散斑干涉测量技术的关键问题之一。数字散斑相关法通过相关搜索算法获得被测试件的位移场，搜索算法的性能将直接影响测量精度的高低及测量的实时性。如何提高相关算法的计算精度和计算效率也成为数字散斑相关技术的关键问题之一。本文的具体工作包括：(1)基于偏微分方程(PDE)的滤波方法是ESPI滤波中的有效工具。本文比较分析了六个非方向偏微分方程和两个方向偏微分方程滤波模型的性能，总结了每个滤波模型的特点及各自的适应性。(2)通过我们的分析比较，结果表明方向二阶PDE滤波模型是一种有效的PDE模型。本文进一步将该模型与几种有代表性的、新近的ESPI滤波方法进行了比较分析，包括窗傅里叶滤波法、正则化二次方向成本函数法、新近的方向模板滤波法和局域傅里叶变换滤波法，并对各方法的滤波性能进行了总结。(3)将径向基函数引入到ESPI信息提取中，包括：针对粗宽ESPI条纹图，提出了基于径向基函数的ESPI条纹图滤波的新方法；将径向基函数应用于条纹骨架线法的条纹级数插值中；采用径向基函数对相位解包裹得到的相位进行平滑处理。利用基于径向基函数的信息提取新方法对三氧化二铝(Al2O3)陶瓷基片在激光照射下不同时刻的热变形进行了测量。(4)提出了一种基于数字散斑相关法和径向基函数插值相结合的位移场分析新方法，径向基函数插值对散乱数据具有高精度的逼近能力，新方法的计算效率同时得到提高。由该方法获得的位移场不再需要任何平滑技术进行后处理。将该方法应用于铝片刚体位移变形场和试验梁三点弯曲变形场的测量，获得了较理想的位移场。更多还原

【Abstract】 Optical measurement technology as a kind of whole-field, non-contactnondestructive measurement technique, has permeated into many fields of scientificand engineering. Electronic speckle pattern interferometry (ESPI) technology anddigital speckle correlation method (DSCM) are two kinds of commonly used opticalmeasurement technology. Information extraction with high accuracy is of fundamentalto optical measurement technology. In this paper some key problems to these twotechniques in information extraction are studied. ESPI measurement delive themeasurement results in the form of fringe patterns or phase patterns, both fringepatterns and phase patterns contain heavy speckle noise, which hampers the extractionof phase information seriously. Therefore, how to reduce the influence of specklenoise effectively, and improve the contrast of the fringe has become one key issue toESPI measurement technology. DSCM acquires the displacements of the testspecimen by use of correlation algorithm. The performance of the correlationalgorithm makes influence on the measurement accuracy and real-timing directly.Improving computing efficiency and accuracy is the key problem in this technique.The work in this dissertation is as follows:(1) The filtering model based on partial differential equation is an effective toolin ESPI filtering. Six non-orientation and two orientation partial differentialequation filtering models are analyzed and compared, and the feature of eachpartial differential equation filtering model and their respective flexibility aresummarized.(2) By use of the analyzing and comparing the eight PDE filtering model, theresult indicates that the second-order oriented PDE model is the mosteffective model. This PDE model is analyzed and compared with severalother representative and recent ESPI filtering methods, mainly including thewindowed Fourier transform method (WFF), the oriented, regularizedquadratic cost function (ORQCF) method, the oriented spatial filter masks(OSFM) and the localized Fourier transform filter (LFF). The summary ofthe performance for these filtering methods are presented.(3) Introducing the Radial basis function(RBF) to ESPI information extraction, mainly including: the new filtering method based on radial basis function forESPI fringe patterns with wide density; introducing the radial basis functionto interpolate the number of fringe in the fringe skeleton method; smoothingthe phase acquired by phase unwrapping algorithm by use of the radial basisfunction. By use of the information extraction method based on RBF, thethermal deformation of the Al2O3ceramic substrate at different moment ismeasured on the circumstance of laser radiation.(4) A new method for displacement field analysis based on the combination ofDSCM with RBF interpolation is proposed. The ability to approximatescattered data make this method has the advantage with better accuracy andless computational time. Another advantage is that this method does notrequire any smoothing algorithm to process the discrete displacement fielddata obtained. Using this method, the displacement fields for rigid bodytranslation and three-point bending are analyzed, the accurate displacementfields are acquired.更多还原