大型上单翼飞机机翼三维全场变形测量方案

针对大型上单翼飞机在飞行过程中机翼大挠度变形检测难题,提出了大倾角相机视场下机翼的非接触三维全场变形测量方案。根据上单翼飞机结构特点,将预先标定内参数和相机外参数的共轭相机组安装于飞机垂直尾翼上,采集飞行中的机翼变形图像。首先,提出了大倾角弱相关散斑匹配方法,解决了相机在大倾斜角度状态下采集到的机翼变形弱相关图像相关性差,难以相关匹配的问题。其次,由于测量相机安装于垂直尾翼,飞行测量过程中相机会受到气流扰动产生振动,本文提出了一种相机动态校正方法,通过在机背布置预拉伸刚性不动编码标志点,实时解算基准相机的绝对外参数,进而确定共轭相机的绝对外参数,实现所有测量相机外参数的动态校正。最后,开发了机翼变形全场测量软硬件系统,搭建了缩小比例机翼模型试验台并进行了仿真测量,对系统测量精度进行了比对分析。测量结果验证了本方案的有效性、可行性,对实机测量有一定的指导意义。

3D full-field wing deformation measurement method for large high-wing airplanes

A non-contact vision measurement system containing heavily sloped cameras is developed to measure 3D full-field wing deformation of the large high-wing airplane during the process of flying.In order to adapt to the structure of high-wing aircraft,pre-positioning internal parameters and relative parameters cameras,as a conjugate group,be installed on the aircraft vertical tail,to collect wing deformation images during flying.Concurrent speckle matching method for overlarge inclined angle is proposed,to solve the matching failure problem,which is caused by low correlation for images collected when wings are at large angle of inclination.Since the cameras are installed at the vertical tail,and would be affected by flight vibration,a real-time inverse calculation camera position method,using fixed pre-stretched points on the top of the plane,is presented to decrease the camera positioning error.Finally,a full-field wings' deformation measurement system,contains software and hardware,is developed,and simulated on a special built scaled theoretical wing model test bench to verify the measurement accuracy of this system.The simulation results prove the efficiency and feasibility of this proposal,and it has guiding significance for real aircraft measurement.