【作者】 何森；

【导师】 侯宏录；

【作者基本信息】 西安工业大学 ， 光学工程， 2006， 硕士

【摘要】 在飞机生产和对飞机进行飞行性能试验的过程中,都要对飞机的副翼、襟翼、方向舵和升降舵等转动系统的角位移传感器进行标定。由于其工作环境特殊,现有的各种精密测角方法都不适用。目前采用的标定方法操作复杂,校准精度较低,不能满足要求。因此,研究一种安装调试简单、操作方便、精度较高、适应能力强的测量方法和测量系统对飞机生产、研制和试验部门显得十分重要。基于计算机单目视觉的测量方法具有很多优点。但现有的方案多采用几个固定点作为测试靶上的“特征标志”,很难建立一个简单适用的求解物、像空间坐标关系的“解算模型”,只好采用一些近似算法,使其用于近距测量时的误差太大,不能满足本项课题的要求。本文采用特征圆作为靶面上的“特征标志”;提出了“特征直径”的概念,采用特征直径及其在像面上的透视投影的位置和长度作为基本的“特征参数”;根据透视投影的规律,应用特征直径的特性,建立了新的“解算模型”,无须在现场标定摄像机的参数,只需采用基本的数学工具即可实时解算出靶面法线的方向。根据上述原理,本文依次提出了单圆靶单目视觉角位移测量方案、双圆靶方案及三圆靶方案,逐步使计算公式更简洁,运算速度更快,系统更加稳定,适用范围更广,而且其中的双圆靶方案还具有不必标定相机内部参数的突出优点。设计了修正由于测试设备安装不到位而导致的误差的修正算法。在图像处理方面,本文设计了标志特征圆圆心位置的特殊方法和亚像素数字图像处理方法,使得特征圆圆心像点的仿真定位精度可达0.01个像素的数量级;提出了一整套围绕特征直径像的特性来寻找其端点坐标的方法。最后,进行了误差分析和计算机仿真,结果表明,采用本方案标定精度可达0.1°。该测量系统结构简单,只需一台数码摄像机和一台计算机。而且能用以DSP芯片为核心做成的专用小型数据处理器代替计算机,将该系统组装成一台小巧轻便的仪器,使用更加灵活方便。该方法不仅适用于非接触实时测量定轴转动刚体的角位移,而且还能直接用于两航天器交会对接或无人驾驶飞机定点着陆的最后逼近阶段实现实时自主精确测量其相对位姿参数。其实用性和适用性都较强,将会有较好的应用前景。更多还原

【Abstract】 We must calibrate sensor against angular displacement for airplanes’aileron , jaw rudder and elevator , and so on , when making airplanes and testing on their flying capabilities. All the methods reported aren’t applicable because of its special working environment here . And the calibrating method being used nowadays can not meet the specific needs , because the operation is complex , and the calibration precision is low . So , inventing a new measuring method , which is simple while installing , convenient when operating , and of higher precision and adaptability , is very important to the making and testing departments of airplanes .The measuring methods based on the computer monocular vision has many advantages . But many present methods , which adopt several fixed points as characteristic mark , are hard to establish a simple and practical“resolving model”to calculate the relation between coordinates in object space and in image space . To overcome this , they use approximate calculating method , but the result is that the error is too big when doing close-range measurement , and it can not meet the needs of this research .Characteristic circle is adopted for characteristic mark; a new concept ,“characteristic diameter”, is put forward ; the length and the position of the characteristic diameter’s image is adopted for the basic“characteristic parameters”; and a new“resolving model”is established based on perspective projection principle and the speciality of“characteristic diameter”in this article , so that the normal direction of target plane can be got without calibrating camera parameters in real time . It only need basic mathematic tools .It has designed a special method for finding circular center image coordinates and a subpixel digital image process method , so that the precision of simulation for searching image point of circular center can reach to 0.01 pixel in grade of amount .It has designed amending method for errors , produced by improper installation position of the testing device .Computer simulation result shows that the error is mostly less than 0.1°, if using this method to calibrate against the angular displacement for airplane’s rudders .更多还原