聚焦和离焦IPI系统采样体积的理论和实验研究

发布时间：2018-04-19 10:05

本文选题：倾斜成像系统 + 采样体积　；参考：《天津大学》2016年硕士论文

【摘要】：光学成像系统是一种重要的光学信息传递和处理系统,在很多领域有着广泛的应用。传统的光学成像系统是物面、镜头主面和像面互相平行的光学系统,但在一些成像系统中物面与镜头主面和像面是不平行的,所以倾斜成像系统的研究很有意义。倾斜成像系统广泛应用于粒子场测量,干涉粒子成像(IPI)系统是其中主要的应用。IPI系统的采样体积是研究粒子数浓度的基础,聚焦IPI系统的采样体积与成像系统的景深有关,而离焦IPI系统的采样体积与成像系统的景深无关。本论文研究聚焦和离焦IPI系统采样体积的计算公式和测量方法,搭建聚焦和离焦IPI实验系统,使用标准网格标定板和标准球形粒子分别对聚焦和离焦IPI系统的采样体积进行测量。本论文的工作对于确定倾斜成像系统的采样体积具有重要指导意义。本论文的主要工作:1.基于几何光学理论分析了IPI测量技术的基本原理,研究搭建IPI实验系统的几个关键问题:系统最佳散射角的选择,样品池不同摆放方式的影响、成像系统放大倍率的校正以及离焦IPI实验系统具体参数的计算。2.研究仅物面倾斜和物像面双倾斜这两种聚焦IPI系统的采样体积,推导采样体积的计算公式,分析采样体积与物面倾斜角、成像镜头焦距和光圈数、系统中心放大倍率的关系。比较两种成像方式发现,物像面双倾斜聚焦IPI系统的采样体积大于仅物面倾斜聚焦IPI系统的采样体积。3.搭建两种物面倾斜聚焦IPI实验系统,采集网格标定板图像,处理图像提取目标横线平均线宽,判断清晰成像范围,得到了聚焦IPI系统的采样体积。4.提出一种离焦IPI系统采样体积的确定方法,根据CCD靶面上每一个位置x处所形成的干涉条纹圆尺寸的范围12pixpixApixA(37)￡(37)￡(37)来确定采样区域。分析离焦条纹圆尺寸与后向离焦距及其在CCD靶面上位置的关系,推导了离焦IPI系统采样体积的计算公式。5.搭建离焦IPI实验系统,采集标准球形粒子的离焦干涉条纹图,对全视场的干涉条纹圆尺寸范围进行了修正,获得了离焦IPI系统的采样体积。
[Abstract]:Optical imaging system is an important optical information transmission and processing system, which has been widely used in many fields.The traditional optical imaging system is an optical system in which the main plane of the lens and the image plane are parallel to each other, but in some imaging systems the object surface is not parallel to the main plane and the image plane of the lens, so the study of the tilted imaging system is very meaningful.The tilted imaging system is widely used in particle field measurement, in which the interference particle imaging system is the main application. The sampling volume of the IPI system is the basis of studying the particle number concentration. The sampling volume of the focused IPI system is related to the depth of field of the imaging system.The sampling volume of defocus IPI system is independent of the depth of field of the imaging system.In this paper, the calculation formula and measurement method of sampling volume of focusing and defocusing IPI system are studied, and the IPI experimental system of focusing and defocusing is built.The standard grid calibration plate and standard spherical particle were used to measure the sampling volume of focusing and defocusing IPI systems respectively.The work of this paper is of great significance for determining the sampling volume of tilted imaging system.The main work of this thesis is 1: 1.Based on geometric optics theory, the basic principle of IPI measurement technology is analyzed, and several key problems in building IPI experimental system are studied: the selection of optimal scattering angle of the system, the influence of different layout of sample cell,Calibration of magnification of imaging system and calculation of specific parameters of defocus IPI experimental system. 2.In this paper, the sampling volume of only two focusing IPI systems is studied. The calculation formula of the sampling volume is derived, and the relationship between the sampling volume and the inclination angle of the object plane, the focal length and aperture number of the imaging lens, and the magnification of the system center is analyzed.Comparing the two imaging methods, it is found that the sampling volume of the object plane double tilted focusing IPI system is larger than that of the only object plane inclined focusing IPI system.In this paper, two kinds of object plane oblique focusing IPI experimental system are built, the grid calibration board images are collected, the average line width of the target line is extracted from the image, the clear imaging range is judged, and the sampling volume of the focused IPI system is obtained.A method for determining the sampling volume of defocus IPI system is presented. The sampling area is determined according to the range of interference fringes at every position x on the CCD target plane.The relationship between the size of defocus fringe circle and the backward defocus length and its position on the target surface of CCD is analyzed. The calculating formula of sampling volume of defocus IPI system is derived.A defocus IPI experimental system was set up to collect the defocus interference fringes of standard spherical particles. The circle size range of the interference fringes in the whole field of view was corrected and the sampling volume of the defocus IPI system was obtained.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH74

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