Bridge Deformation Measurement Using Unmanned Aerial Dual Camera and Learning-Based Tracking Method

Abstract

Bridge deformation response data are the basis for calculating the dynamic parameters of the bridge, and it is of great significance to accurately measure the deformation response of the bridge during the load test and service conditions. A bridge deformation measurement method using an unmanned aerial system (UAS) with dual cameras and a deep learning-based object tracking method is proposed to measure the bridge deformation. The contributions are as follows: (1) To address the problem that the movement of the UAS brings error to the deformation measurement results, dual cameras with telephoto and wide-angle lenses are used to simultaneously capture the deformed points and stable points on the bridge, so as to simultaneously measure the deformation of the bridge and the displacement of the UAS, and then the displacement of UAS is eliminated by using the homography relationship between the two cameras. (2) To solve the problem that the traditional digital image correlation-based displacement measurement method is easily disturbed by factors such as light changes and occlusion, a displacement calculation method based on object detection network and target tracking algorithm is proposed to achieve the stable target displacement measurement. Finally, the proposed method was verified in a laboratory test and applied to the deformation measurement of an in-service bridge to verify the practicability of the proposed method.

Computer Vision-Based Bridge Inspection and Monitoring: A Review

“…Liu et al [ 176 ] developed a bridge vibration displacement measurement system based on UAV and DIC, and corrected the deviation caused by UAV vibration through a homography matrix. Jiang et al [ 177 ] proposed a bridge vibration displacement measurement method based on a DL-based target tracking method and a dual-camera UAV system. When using their method, deformation point and stable point on the bridge are simultaneously captured by dual cameras with telephoto and wide-angle lenses, and the vibration displacement of the bridge and UAV is measured simultaneously, and the displacement of the UAV is eliminated by using the homography between the two cameras.…”

High-Precision Monitoring Method for Bridge Deformation Measurement and Error Analysis Based on Terrestrial Laser Scanning

“…The image coverage and monitoring accuracy in this method are contradictorily limited by camera hardware. Therefore, vision-based methods are mainly oriented toward the deformation of local areas or key points in a long-span bridge [20][21][22][23][24]. The structure should be divided into multiple monitoring windows for simultaneous monitoring to achieve geometric continuity through image stitching to achieve a high monitoring accuracy and improve the monitoring range [25].…”