Unmanned Aerial and Traversing Robot as Mobile Platform for Bridge Inspections

In this study, a bridge inspection robot deployment system (BIRDS) is designed, prototyped, and tested to facilitate the remote inspection of bridges with nondestructive evaluation tools such as microwave and hyperspectral cameras. The multimodal robotic system utilizes both flying and driving technologies. First, BIRDS as an unmanned aerial vehicle flies to the underside of the bridge to be inspected. When in position, BIRDS is engaged with the bottom flange of a bridge girder with a specifically designed roller clamping system and then traverses the bridge in a stable manner, providing high quality images from cameras. Finally, BIRDS simply detaches from the bridge as it encounters obstacles, and flies to the next area of interest. The power system of the BIRDS was designed for over one hour of operation. To meet lightweight, durability and strength requirements, the main frame of the BIRDS was made from ¼” thick carbon fiber reinforced polymer sheets. Smaller components were made with a 3D printed discontinuous fiber-reinforced nylon, characterized with tensile, compressive and shear tests. The first prototype was built and tested in laboratory. Preliminary tests demonstrated the successful engagement, traversing and disengagement of the prototype BIRDS along a simulated bottom flange of a beam. However, the four rotor arms appeared too flexible and should be stiffened to minimize any impact-induced deflection during landing