基于远心系统的三维测量方法研究.docx

基于远心系统的三维测量方法研究摘要:基于条纹对比度的三维测量方法由于具有垂直测量的特点，可用于测量表面有突变的复杂物体的三维信息。本文在现有方法的基础上，提出了一种改进的基于远心系统的三维测量方法。光路系统由投影系统和观测系统两部分组成：投影系统使用平行光路，将光栅条纹投射在被测物体上，并使被测物体位于投影系统成像面的前方；观测系统使用置于步进电机控制器上面的远心镜头，通过CCD相机透过一个半透半反镜在垂直于光路的方向获取一系列物体表面的条纹图像，然后利用傅里叶变换术得到条纹在不同位置的对比度分布，最后利用该对比度和高度的对应关系恢复出物体高度。该方法基于远心系统的设计解决了阴影遮挡问题，特别适合于探测表面有高度剧烈变化（如深孔）的物体。实验结果展示了拥有深坑和大高度间断的物体的面形测量结果。实验结果表明该方法算法简单，且可以达到较高的测量精度。关键词：远心系统；光学测量; 调制度测量轮廓术；三维重建；傅里叶变换A modified contrast measurement profilometry which based on a telecentric optical systemAbstract: The profilometry based on the fringe contrast is a vertical 3D measurement technique，which can measure thecomplex objects with acute changes in their surfaces．A modified contrast measurement profilometry which uses a telecentric optical system based on theprevious method is proposed．The optical system is consists of two parts: in the projectionsystem，grating fringes are projected on the surface of the testing object which laid in front of imaging plane using parallel light; While in the observationsystem, we adopt a telecentric lens which placed above a stepper motor controller. A series of images of the fringes captured through a beam splitter by a CCD camera in the direction perpendicular to the light path. We can obtain the fringescontrast in different positions using Fourier transform technique，and then restore the height of the object through the map of the contrast and theheight．This method based on the telecentric optical systemavoid the shadings and particularly suitable for those objects with large height discontinuities (such as deep holes). Experimental results are presented that demonstrate theshape measurements of objects with a deep hole and large discontinuities.The results proves that this method is simple and greatly accurate．Key words:telecentric optical system; optical measurement; modulation measurement profilometry; 3-D reconstruction; Fourier transform目录第一章 绪论1.1 三维测量方法概述1.2 三维测量常用方法及存在的主要问题1.2.1 光切法1.2.2 莫尔条纹法1.2.3投影光栅相位法1.2.4近年研究热点条纹图形处理技术的发展