Structural health monitoring of structures using UAVs

Unmanned aerial vehicle (UAV) imaging is a novel technology allowing engineers to monitor, analyse and assess the health of civil engineering structures such as bridges and high-rise buildings. This innovative technique uses a remote sensing platform in combination with a high-resolution camera for video and image acquisition. An understanding of the application and image processing methods is needed for implementing this advanced technology in structural health monitoring of structures, particularly in long span bridges. This paper presents experimental test methods integrating sensors, data acquisition. UAVs and image processing for measuring the static deflections and natural frequencies of beam specimens. The static beam deflections are generated by loading the beam in the mid-span using incremental weighs whereas free vibration of a cantilever beam is achieved by exciting the free end of the beam. In this study, a multi-rotor remote controlled UAV equipped with a high-resolution camera mounted on a mechanical gimbal mechanism is used to record video footage and still images. Static and high-speed cameras are also used for comparing the measurements with the data obtained by the UAV. The recorded measurements are processed by image processing techniques to assess the beam deflections and free vibration frequencies using Vic-2D and Matlab software. These investigations can form the basis for developing novel approaches and methodologies for investigating the deformation characteristics of bridges and monitoring of structures.