摘要粒子图像测速技术(Particle Image Velocimetry, PIV)是一种进行流场流速测量的技术。 与传统的其他测定相比，PIV 技术有着无扰动、非接触、瞬态实现二维平面内二维速度矢 量(2D2C)测量的优点。随着流体力学实验技术的发展，三维 PIV 技术逐渐成为研究热点， 如扫描-PIV、全息-PIV 和 Tomo-PIV 等。通过上述三维 PIV 技术可以实现待测场三维空 间内三维速度矢量(3D3C)的测量，对研究复杂的流体动力学过程，如涡流、湍流等具有 重要的实用价值。但是，在实际的风洞测试实验中，往往仅有有限的观察窗口来采集示 踪粒子散射图，不允许在风洞内布置太多的实验装置。针对此问题，本文考虑研究仅需 一个投影方向，通过平面相机阵列来实现 3D3C 流速测量的合成孔径 PIV 技术。77268

实现合成孔径成像的三维 PIV 技术的前提是需要布置摄像机阵列，需要精确的知道 布置相机的位置，即要进行摄像机标定。本文在对摄像机标定技术的发展进行分析的基 础上，分析了标定实现的过程与标定的原理。并进行摄像机标定实验。对摄像机阵列拍 摄得到的图像进行处理，设计编制了标定点识别程序，通过识别图像中的椭圆，获得标 志点的坐标位置，并编制程序计算摄像机的内外参数。

在上述工作基础上，研究了三维合成孔径 PIV 技术的理论原理，设计并编程实现了 示踪粒子散射图像重映射算法。通过模拟平面相机阵列，进行了模拟实验。对模拟的结 果进行分析，推断出现误差的可能原因。

布置一个 3*3 的相机阵列进行基于合成孔径成像的三维 PIV 实验，通过摄像机标定 确定各相机的内外参数，并进行三维 PIV 实验，拍摄示踪粒子散射图，并进行图像预处 理。

毕业论文关键词 合成孔径成像 三维粒子图像测速技术 摄像机标定 图像处理

毕业设计说明书外文摘要 

Title Three-dimensional PIV Technology Based On Synthetic Aperture Imaging

Abstract  Particle image velocimetry (PIV) is a technique that determines the velocity field of fluid。 Compared with other traditional measurements, PIV has advantages like undisturbed, non-contact and instantly measuring two-dimensional velocity vector (2D2C)  in two-dimensional plane。 With the development of fluid mechanics experimental technology, three-dimensional PIV is becoming a hot research, such as scanning-PIV, holographic-PIV, and Tomo-PIV and so on。 Through those three-dimensional PIV, three-dimensional velocity vector (3D3C) of three-dimensional space can be measured。 These measurements have important practical value for complex fluid dynamics research, such as eddy, turbulence。 However, in the actual wind tunnel experiments, there are only limited observation windows to capture tracer particles scatter plot and do not allow too many experimental device disposed within the wind tunnel。 In order to solve this problem, synthetic aperture PIV with the plane array camera is used to achieve 3D3C flow measurement, which considers only one projection direction。

The precondition of synthetic aperture PIV is camera calibration, that is, to lay the camera array, to know the exact location of the camera arrangement。 Based on the introduction of the camera calibration technique development, process of calibration and the principles of calibration are analyzed and camera calibration experiments are finished。 An array of images captured by the camera is processed, and standard identification procedure is prepared that is designated to identify the elliptic and obtain the location of landmarks。 Finally, another program is made to calculate internal and external camera parameters。