Research on Dynamic Structure Displacement Monitoring Based on Feature Optical Flow Method

In view of the difficulty of sensor installation and complicated process in traditional structure health monitoring, a feature point monitoring based on optical flow is proposed in this paper. A high-speed camera is applied to capture the dynamic response of the structure under excitation, and feature point could be selected and marked at any position in the video. The movement of the selected point could be traced and calculated by feature optical flow method, and the displacement time series of the feature point could be obtained. Results show that the displacement time series obtained from proposed method in this paper is consistent with the data of the pull-wire displacement sensor, the maximum displacement error is 3.3%, the method proposed is more flexible, convenient and of low cost.