Research On Structural Deformation Monitoring Technology Based On Binocular Stereo Vision

To meet the growing demand for the full filed and non-contact measurement in the structural health monitoring field, a binocular stereo vision measurement technology applied to the civil engineering field is developped in paper. The paper focuses on reasearch about the system integration, the recognition and matching and tracking of artificial targets, the displacement and strain measurement algorithm, the system performance test and the static and dynamic experiments. The structural surface crack width detection algorithm is also studied and tested by experiments. The main contents are introduced as below:Firstly, the structural defromation measurement algorithm based on the binocular stereo vision is proposed in paper, and the recognition and center subpixel localization algorithm of circular artificial targets is also developped, which includes the Canny-Zernike subpixel edge detection algorithm and the least squares fitting algorithm of Ellipse Center. Aimming at the simultaneous matching problem about identification points on left and right cameras and the tracking problem about identification points in image sequences, the epipolar constraint matching algorithm based on the symmetric test and the Kalman tracking algorithm are both studied, and the good results are obtained.Secondly, the structural defromation measurement system based on binocular stereo vision is integrated in reaserach, the system can monitor the structural full-field displancement and strain through the image collecting and processing in non-contact way. The precision and sensitivity of the measurement system is tested by experiments.Thirdly, the system practicability and reliability about monitoring the static and dynamic structural deformation is verified by the loading experiment of concrete beam strengthened with UV-GFRP, the vibration table experiment of masonry house and the free vibration experiment of the bridge cable,Finally, the surface crack width inspection algorithm based on binocular stereo vision is suggested, this algorithm recovers the 3D information of crack by projecting the crack edge to the space plane. This method is effectively improved the 3D recovery speed, and the inspection precesion is tested by the concrete crack inspection experiment.