关键词: 薄膜结构, 三维动态测量, 摄影测量, 点阵投影式, 立体视觉

Abstract: Aiming at the shortcomings of the conventional vision measurement method in the dynamic measurement of membrane structures, the target affects the local deformation of the film. The 3D dynamic measurement technology of membrane dot matrix projection is proposed. This technology uses a laser to project the target onto the membrane structure. Based on the OpenCV library（Open Source Computer Vision Library）, the 3D measurement algorithm is proposed to measure the 3D dynamic deformation of the membrane structure. In order to verify the 3D measurement accuracy, a standard ruler for accuracy inspection is designed. The 3D measurement accuracy of the membrane structure dot matrix projection measurement technology is tested in the principle verification experiment. The overall deformation and wave deformation of membrane structure are measured by 24 Hz frame rate photography and offline data processing. Accuracy verification experiments show that the technique can achieve the absolute accuracy of less than 0.30 mm and an accuracy of about 0.77 mm in the X, Y and Z directions, respectively, at the measurement distance of 1 m and the field of view of 1.3 m×0.8 m. At the same time, the dynamic measurement results can effectively replicate the dynamic deformation process of the membrane structure.

Key words: Membrane structure, 3D dynamic measurement, Photogrammetry, Dot matrix projection, Stereovision.