【作者】 王占斌；

【导师】 赵辉；

【作者基本信息】 上海交通大学 ， 测试计量技术及仪器， 2007， 博士

【摘要】 管件(管形零件)大量使用于生产生活当中,例如:城市的污水管道、自来水管道、国家的石油管道、深埋地下或海底的光纤电缆管道、军事上的枪膛和炮筒等等。这些形状、大小、材质各异的管件在生产时需要严格地质量控制和参数检测,因此管件内轮廓三维测量与重建方法的研究具有显著的实用价值和学术研究价值。由于管件内轮廓的封闭性、不可见性和空间狭小,给内轮廓参数测量和内表面检测带来了很大困难。特别是管件内表面一般较为粗糙,使得检测的难度更大。因此,如何快速有效地测量管件内轮廓参数和了解其内表面情况,一直以来都是一个难题。本论文的研究目的是寻找一种能适用于不同材质、不同形状、表面粗糙的管件内轮廓高精度非接触测量方法;同时能够依据测量得到的数据对管件内轮廓进行评价和快速重建。在分析国内外现有测量方法与原理的基础上,本文提出一种“基于自动增益环形离散结构激光的视觉检测方法”,采用多点光强增益独立控制的激光器和多模光纤组件产生对称结构激光光源,利用高精度工业CCD摄像机来获取管件内轮廓测量点云数据,通过图像处理和本文提出的管件内轮廓参数快速提取算法来计算管件内轮廓参数,最终重建内轮廓三维形状。通过查新表明,本文提出的测量方法在国内外未见报道,具有创新性。本课题主要包括两方面内容:管件内轮廓三维测量方法的研究和管件内轮廓三维重建方法的研究。这两部分既相互关联,又有相对独立性。管件内轮廓测量部分主要完成内轮廓点云数据获取和内轮廓特征参数计算;内轮廓重建部分主要主要完成内轮廓三维再现。本文完成了以下主要工作:1.阅读了大量参考文献,对目前国内外现有的管件测量方法进行了分类和分析,并指出了各自方法的优缺点;同时分析了现有曲面重建方法的难点和不足。2.结合现有的视觉测量方法提出了四种新的视觉测量方法:对称分布式结构法、垂直分布式结构法、外反射集中式结构法和内反射集中式结构法,并建立了较为完整的数学模型。3.设计了一种新颖的自动增益环形离散结构激光光源,并在此基础上构建了相应的实验系统,同时对系统的非线形元件(广角镜头)的畸变与修正进行了研究。该系统用来验证新方法的有效性与实用性。4.提出了一种管件内轮廓参数快速提取算法,该算法主要包括母线重采样、母线差分、母线滤波、落差法分区、直线回归和内轮廓参数计算等几个步骤。新的算法能够快速处理管件内轮廓点云并提取出其特征参数。通过对实际钻杆的实验测试表明,新的方法可以在短时间内完成对一根钻杆的全部测量,并表现出良好的抗干扰能力和稳定性,同时可以获得足够的测量精度。5.本文提出一种新的“基于母线特征的主动细分内轮廓三维重建”方法,实现了三维管形封闭曲面重建过程。该方法主要包括封闭曲面分片、单片曲面重建和曲面拼接与缝合三步。封闭曲面分片采用了基于母线特征的主动细分方法;单片曲面采用NURBS曲面重建;曲面拼接与缝合由三次样条和昆氏双三次曲面完成。通过对实际钻杆的实验测试表明,新提出的管件内轮廓重建方法可以快速自动完成管件内轮廓重建,并获得理想的重建精度。总之,本文所作的研究对于研制相应的测量装置具有普遍的指导意义;这些方法应用于实践可以大大地提高测量效率、降低劳动强度、带来显著的经济效益。更多还原

【Abstract】 Pipe figure components can be found everywhere in our lives: municipal sewage pipes and fresh-water pipes, petroleum pipes, fibers or cable pipes imbedded underground or at the bottom of the sea, gun barrels and cannon barrels, deep holes in workpieces, etc. All of these pipe figure components with rough inner-surface are made from different materials and have different shapes and sizes, whose geometric parameters and quality need to be measured accurately and controlled strictly during production. So, Measurement and reconstruction for inner-contour of pipe figure components is a subject which has significant practical value and academic research significance. The specialty of pipe figure components, e.g., closed, unseen, and narrow spaces, leads to many difficulties during parameter measurement and inner-surface inspection. Therefore, how to measuring the parameters and learning the inner-wall of pipe figure components rapidly and efficiently is always a big problem.The new non-contact measurement method needs to be proposed for different pipe figure components with different materials and sizes. At the same time, how to evaluate and reconstruct the inner-contour of pipe figure components according to the captured data is a problem waitted for solving. After reading many references and completing many preresearch works, the new visual method based on automatic gain ringy discrete structured laser was proposed, which can be used to capture the cloud data of inner-contour. The new structured laser was composed of multimode optical fiber component and laser device component whose sigle intensity could be controlled independently. The new method employed the high-resolution industry CCD to capture the inner-contour’s cloud data. On the base of captured cloud data, the inner-contour parameters can be calculated and the inner-contour can be reconstructed. Before research proposalling, a novelty retrieval work was done for the measurement methods and the data processing methods proposed in this paper. The novelty report showed that these new methods have certain innovation.The subject mainly includes two aspects, which were the research on the measurement and reconstruction method for inner-contour of pipe figure components. The two relative independent aspects have a close relationship. The first aspect mainly complete the cloude data capturing and characteristic parameters calculated, and the second aspect mainly reproduction the inner-contour of pipe figure components.According to the two main research aspects, this dissertation compeleted many works summarized as follows:1. After reading many references, we classified and analyzed all the measurement methods metioned in these references, and pointed out the advantages and disadvantages of different method. At the same time, we summarized the difficults and defects of available surface reconstruction methods.2. Combining the existed visual measurement methods, four new methods were proposed in this dissertation, which were Symmetrical Distributed Structure method, Vertical distributed structure method, External-reflection Integrated Structure method and Internal-reflection integrated structure method. According to the structure of the four methods, the mathematical model was built correspondingly.3. A new ringy structured laser was designed in the dissertation. On the basis of the new ringy structured laser, an experiment system was constructured and calibrated for verifying the validity and practicality of the new methods. For improving the precision of the measurement system, some work was done for correction the distortion of non-linear component (large-angle lens).4. The fast algorithms for capturing the inner-contour cloud data and extracting inner-contour feature parameters were proposed in this dissertation. The new algorithm was composed of several steps, which were generatrix resample, generatrix difference, generatrix filter, falling method division, subsection linear fitting and inner-contour feature parameters extracting. In the experiment, the new methods obtained well performace on anti-disturbance ability and stability, and got enough measurement precision.5. Lastly, reference to the reconstruction processing of free closed surface, a new reconstruction method for inner-contour of pipe figure components was proposed, which named as active subdivision 3D reconstruction method based on generatrix characters. The new method was compoed of three steps, which were closed surface subdivision, single surface reconstruction and surface blending & suture. Firstly, the closed surface subdivision employed active subdivision method based on generatrix characters. Secondly, the single surface was reconstructured by NURBS surface. Thirdly, all these surface patchs were blent and sutured by the cubic spline or the bicubic curved surface of coons. In the experiment, the new method could compeleted the inner-contour reconstruction of pipe figure components fastly, and obtained higher reconstruction precision.In conclusion, all the research works in this dissertation can give a guide to develop the similar measurement apparatus, at the same time, in practice, which can improve measurement efficiency, reduce labor intensity, and bring significant economic benefits.更多还原