结构位移摄像测量系统的设计与实现

Design and realization of videometric system for structural displacement measurement

针对飞机等大型工程结构的位移测量需求,设计实现了结构位移摄像测量系统。该系统采用多台数字式摄像机从不同方向拍摄飞机机身、机翼表面的人工合作标志点,在试验前对各个摄像机的参数进行精确标定,试验过程中实时分析各摄像机采集到的序列图像,检测跟踪得到标志点在图像上的二维像点坐标,根据像机参数和标志点二维像点坐标交会计算得到各标志点的三维坐标,即可得到整个结构的位移与变形参数。结构位移结果可进行三维动画显示,也可随时查看各标志点的位移曲线。精度测试结果表明该系统位移测量误差标准差小于1 mm,相对误差小于1%。该系统已成功应用于飞机机翼位移测量中。

Measurement of 3 dimension structural displacement with wide range and high precision is needed in the manufacturing process of large airplanes. For the displacement measurement requirement of airplanes and other great engineering structures, a videometric system of structural displacement was designed and implemented. The system adopted several digital cameras to take photos of the cooperative mark-points located on the frame and wing of the tested airplane from different directions, the parameters of the cameras were calibrated before the test, the image sequences acquired by the cameras were analyzed in real time during the test, the 2-dimension coordinates in the images of the mark-points were detected and tracked. Based on the camera＇s parameters and mark-points＇ 2-dimension coordinates, the 3- dimension coordinates of the mark-points were calculated, then the displacement and deformation of the structure were obtained, the 3-dimension results were visually provided, and the displacement curve was examined. The test results showed the standard deviation of system＇s displacement measurement error is less than 1 mm, and the relative error is less than 1%. The system was used in the wing displacement measurement of a specific airplane, and the efficiency and precision of the measurement were improved.