【作者】 王小力；

【导师】 马卫红；

【作者基本信息】 西安工业大学 ， 武器系统与运用工程， 2011， 硕士

【摘要】 飞行体的姿态是飞行体理论研究的重要课题,而章动角是飞行体姿态的主要内容之一。章动角的变化是否正常是判断飞行体是否稳定的直接因素,因此,章动角的测试具有重要意义。本文主要解决基于线阵CCD采集图像的章动角测试系统中,图像分析与工程化数据处理中的关键技术问题。针对飞行体速度高的特点,采用两台高速线阵CCD相机交汇的方法,分别测试两个正交方向的章动角数据,进而获得飞行目标的空间章动角。研究了从图像数据和测试系统参数中获得章动角数据的方法,确定了章动角计算的技术步骤：图像采集、目标分割、飞行目标中心坐标序列提取、飞行目标轴线拟合、尺度对应。分析了线阵CCD采集图像的原理及图像特性,采用差影法分割目标和背景,利用OSTU法计算阈值并分割图像,逐行读取像素值提取目标所在行的坐标值,进而利用平均数法计算目标在各行的中心坐标,采用最小二乘法将这些中心点拟合成轴线,经过尺度对应后,计算章动角的值。通过对测试原理的研究和深入分析,推导了章动角计算公式,解决了基于CCD图像分析的章动角测试方法工程化中,飞行方向与章动方向的尺度对应问题,从而获得可靠的章动角数据。进一步对章动角计算公式中关键参数的获取方法进行了研究,并详细分析了各参数对测试精度的影响。用MATLAB7.1软件验证了图像分析与处理算法,借助OPENCV1.0函数库在VC++6.0开发平台下实现了章动角的测试。同时,创建了动态链接库,利用VC++6.0中的MFC将章动角的测试开发成具有可视化界面的软件。使用帧频为68000f/s的Dalsa-P2-04k40型线阵CCD相机在实验室对气枪弹实际章动角进行测量,经过理论分析,测试精度可达4%。实验表明,本文采用的章动角测试方法可行,测试数据可靠。更多还原

【Abstract】 Flying objects’posture is an important subject in theoretical research of flying, and nutation angle is one of the main research issues. The status of nutation angel’s diversification is a direct factor for judging the stability of the flying object. Therefore, the test of nutation angle is of great significance. The research here focuses on the key technological issues of image analysis and engineering data processing in nutation angle test based on image acquisition by linear CCD.Due to the high speed of the flying objects, a method of using high rate linear CCD intersection to measure nutation angles of two orthogonal directions is proposed, and the space nutation angel is achieved through the measurement. The method of getting nutation data from image and testing system is studied, and technological steps for calculating nutation angle are identified:image’s collection, target’s separation, center coordinate’s calculation of every line and axis fitting. The principle of linear CCD image collection and characteristics of image are studied; background and target are separated by substation; threshold is obtained by OSTU; target’s coordinate is got by reading pixel value line by line; center coordinate of every line is calculated by average method and is fit into axis by least squares method; and nutation angle is calculated after scale corresponds.The calculation formula is also derived from the research and analysis of testing principle. The problem on the relation between the flying direction and nutation direction is resolved in engineering testing method of nutation angel based on CCD image analysis, and reliable nutation angel data are acquired. Moreover, research on acquisition method of the key parameters in calculation formula is made, and the effect on testing precision is analyzed.Image analysis and processing algorithms are verified by MATLAB7.1. The test of nutation angle is achieved by VC++6.0 with the help of OPENCV1.0 library. At the same time, a dynamic link library is created, and a visual interface software is developed by the MFC of VC++6.0. The actual gas cartridges nutation angle is measured in laboratory by linear CCD (Dalsa-P2-04k40) produced from DALSA Company with frame rate 68000. After theoretical analysis, the total nutation angle error is 4%.The test result shows that the nutation angel’s testing method is feasible and the data is reliable.更多还原