【作者】 段晓杰；

【导师】 段发阶；

【作者基本信息】 天津大学 ， 测试计量技术及仪器， 2013， 博士

【摘要】 本文依托国家自然科学基金面上项目和精密测试技术及仪器国家重点实验室探索性课题，研究小尺寸物体表面三维形貌动态测量技术，发展了一种基于光纤干涉条纹投射的结构光三维形貌测量方法：采用马赫-泽德光纤干涉仪结构和杨氏双孔干涉原理实现高密度余弦分布干涉条纹结构光投射，通过面阵相机采集受被测物体调制后的变形干涉条纹图像，利用傅里叶变换轮廓术算法并结合测量系统数学模型，最终实现对被测物体表面三维形貌的恢复与测量。论文主要研究内容包括：1、进一步研究基于马赫-泽德光纤干涉仪结构和杨氏双孔干涉理论的小视场范围高密度条纹结构光投射方案，并建立光纤干涉条纹投射系统数学模型，通过建模仿真研究系统结构参数对投射条纹性质的影响。实际搭建双光纤干涉条纹投射系统，通过面阵相机采集投射光场内干涉条纹图像并分析，验证方案可行性。2、以补偿干涉条纹随机相位波动为目标，提出利用光纤干涉臂输出端面菲涅尔反射信号设计实现闭环相位稳定控制系统；通过直流相位跟踪和交流相位跟踪干涉条纹相位稳定控制方法，驱动压电陶瓷改变光纤干涉臂长度以控制干涉光波相位差，实现投射干涉条纹不随环境温度波动而产生相位漂移。3、以精确提取干涉条纹相位信息为目标，提出高斯变换函数算法对实际采集干涉条纹图像进行补偿，实现条纹背景光强的均匀分布。提出采用条纹等值线滤波算法，在滤除干涉条纹图像中随机噪声的同时保持其余弦分布特征。对干涉条纹图像背景光强、空间频率、噪声对傅里叶变换相位提取过程中的频谱混叠及相位解包裹影响进行研究，为带通滤波器窗口选择、相位展开误差消除、干涉条纹相位信息精确获取提供依据。研究双频相位解包裹算法并进行仿真验证，为实现双波长光纤干涉条纹投射高精度三维形貌测量提供算法基础。4、构建了光纤输出端面和相机镜头连线与被测物体参考平面在非平行条件下的干涉条纹相位信息与实际三维坐标信息的数学关系模型。根据干涉条纹相位差值与被测物体表面高度信息的线性对应关系，采用隐式标定法实现对测量系统结构参数的快速获取，并通过误差分析对系统结构参数进行优化设置。5、搭建光纤干涉条纹投射三维形貌测量实验平台，利用该平台对小尺寸物体表面三维形貌及模拟产品表面三维缺陷进行测量；通过高帧频面阵相机实现对橡胶膜动态形变过程的三维立体恢复。更多还原

【Abstract】 This dissertation is supported by the National Nature Science Foundation ofChina (NSFC) and State Key Laboratory of Precision Measurement Technology andInstrument Explore Fund, researching on the dynamic measurement technology forthe small-size object surface3D shape, developing a new3D shape measurementmethod based on the optical-fiber interference fringes structured light projection,which utilizes the Mach-Zehnder fiber interferometer structure and the theory ofYoung’s two-hole interference, to realize the projection of interference fringes whichhave high-density and cosine distribution, therefore acquiring the interference fringesimages modulated by the measured object through array camera, using FourierTransform Profilometry and combining with the mathematic model of measurementsystem, finally realizing the3D morphology reconstruction and measurement of thetest object.The main research contents are shown as follows:1、This dissertation takes a further study on the program which projectinghigh-density fringes structured light in the small field of view based on Mach-Zehnderfiber interferometer structure and Young’s two-hole interference theory, and constitutethe mathematical model of optical fiber interferometer fringes projection system, thendiscusses the characteristics of projection fringes influenced by system structureparameters through modeling and simulation, building the double-fiber interferometerfringes projection system, acquiring and analyzing the interference fringe images inthe projection light field through array camera, which confirmed the feasibility of theprogram.2、With the target of compensating random phase fluctuation of the interferencefringes, designing a closed-loop phase stabilizing system through Fresnel reflectionsignal from the optical fiber output end, utilizing the methods of DC phase tracking(PTDC) and AC phase tracking (PTAC) phase control process, to drive thepiezoelectric ceramics transducer (PZT) for changing the length of optical fiberinterference arms, then controlling the interferometer phase difference, ensuring thephase of the interference fringes were not drifted by the temperature fluctuation in theexperimental environment. 3、In order to extract the phase information from the interference fringe imagesaccurately, proposing Gauss transformation function algorithm to make compensationof the actual interference fringes images, realizing the uniform distribution of theimages back-ground intensity; Using Fringe Equivalence Line Filter (FELF) methodto filter out the noise and retain the cosine distribution feature of the fringe patterns.Studying the background light intensity, spatial frequency and noise in theinterference fringes images, which make influence on the spectrum aliasing and phaseunwrapping result in the process of fringes phase extraction, provide the basis for theselection of the band-pass filter window, error elimination of phase unwrapping, andachieving the phase information of the interference fringes images precisely; studyingthe dual-frequency phase unwrapping algorithm and taking the simulation experiment,to provide the algorithm basis for the high precision3D morphology measurementbased on the dual-wavelength optical fiber interference fringe projection.4、 Building the mathematical model between interference fringes phaseinformation and the actual3D coordinate in the non-parallel condition of fiber outputend and camera lens connecting line with the measured object reference plane,according to the linear relationship between the phase difference of the fringes andheight information of the tested object, using the implicit calibration method forgaining the structure parameters of measuring system, and taking the error analysis toget the optimization of system structure parameters.5、Establishing the measurement experimental platform of3D shape based on thedual-fiber interference fringes projection, and utilizing the platform to measure thesurface morphology of small size object and3D defects of the simulation products,then realizing the3D stereo recovery of dynamic deformation process of rubbermembrane by the high-frame-rates array camera.更多还原