基于三维散斑相关法的机翼变形测试方法研究

发布时间：2018-04-14 21:08

本文选题：机翼变形 + 三维散斑相关法　；参考：《中国民航大学》2016年硕士论文

【摘要】：飞机机翼变形对飞机性能和人员安全有直接的影响,实施对变形规律的测试意义重大。传统的机翼变形测试方法普遍存在测量点数少、实时性差等缺点,而近年来发展成熟的三维散斑相关视觉测量技术,具有精度高、实时性强、受环境影响小以及非接触全场测量等优点,用于机翼变形测量中能很好地克服传统方法的不足。因此本文对基于三维散斑相关法的机翼变形测试方法进行研究。首先,分析了二维数字散斑相关法的相关计算原理并推导了双目立体视觉的深度信息计算公式,在两者的基础上进行三维数字散斑相关法关键技术的研究,包括摄像机标定的方法、匹配的本质和三维重建的步骤。其次,结合三维散斑相关法原理和机翼变形测试特点,构建出测试方案的系统布局。在该布局下对测试的核心三维散斑相关检测与处理部分进行研究,建立起机翼形变的表征模型,选取可以有效抗干扰的ZNSSD相关函数,分析常规变形参数初值估计法用于机翼变形测量中的问题,最后在本文的实验设备下对亚像素定位中的NR法和IC-GN法进行理论分析及仿真比较。再次,提出一种新型的变形参数初值估计方法,该方法通过在散斑图像上粘贴反射系数极高的圆形标志点,利用标志点匹配的精确性来提高变形参数初值估计的精度。在对标志点匹配时,针对以散斑为背景的图像特点,提出了一种改进的SIFT算法,该算法将极值点检测约束在显著的边缘区域,经实验验证该算法对标志点的提取更有效。最后,搭建测量系统完成实验研究。第一个实验对提出的变形参数初值估计方法进行验证,证明了该方法能够为亚像素迭代提供精确的初值,同时满足工业中的实时性要求;第二个实验通过制作机翼模型,对整个变形测量方案进行简单实现,很好地验证了本文方案的有效性。
[Abstract]:Wing deformation has a direct impact on aircraft performance and personnel safety.The traditional methods of wing deformation measurement have many disadvantages, such as low number of measuring points and poor real-time performance. In recent years, 3D speckle correlation vision measurement technology has been developed, which has high precision and high real-time performance.Because of the advantages of low environmental impact and non-contact full-field measurement, it can overcome the shortcomings of traditional methods in wing deformation measurement.Therefore, the method of wing deformation measurement based on three-dimensional speckle correlation method is studied in this paper.Firstly, the correlation calculation principle of two-dimensional digital speckle correlation method is analyzed, and the depth information calculation formula of binocular stereo vision is derived. The key techniques of 3D digital speckle correlation method are studied based on the two methods.It includes camera calibration method, matching essence and three-dimensional reconstruction steps.Secondly, according to the principle of 3D speckle correlation method and the characteristics of wing deformation measurement, the system layout of the test scheme is constructed.In this layout, the core 3D speckle correlation detection and processing part of the test is studied, and the characterization model of wing deformation is established, and the ZNSSD correlation function, which can effectively resist interference, is selected.This paper analyzes the problems of the conventional method of estimating the initial values of deformation parameters in the wing deformation measurement. Finally, the theoretical analysis and simulation comparison of NR method and IC-GN method in sub-pixel positioning are carried out under the experimental equipment in this paper.Thirdly, a new method for estimating the initial values of deformation parameters is proposed. By affixing circular marks with extremely high reflectivity to speckle images, the accuracy of initial value estimation of deformation parameters can be improved by using the accuracy of mark points matching.An improved SIFT algorithm is proposed to match the image with speckle background. The algorithm restricts the detection of extreme points to the prominent edge region. The experimental results show that the algorithm is more effective for the extraction of marker points.Finally, the measurement system is built to complete the experimental research.The first experiment verifies the proposed method for estimating the initial values of deformation parameters, which proves that the proposed method can provide accurate initial values for subpixel iteration and meet the real-time requirements of industry.A simple implementation of the whole deformation measurement scheme is carried out, and the effectiveness of the proposed scheme is well verified.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V214.11;TP391.41

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