Fully-actuated, corner contact aerial robot for inspection of hard-to-reach bridge areas

This paper presents the design and development of a fully-actuated platform for the visual inspection of difficult-to-reach areas of bridges, such as bridge beams and bearings. The aerial platform incorporates a carbon fiber structure with spherical wheels that facilitates safe contact with the bridge, while the fully-actuated configuration allows the movement of the platform while keeping the contact with the surface. In addition, the system mounts a camera that allows an operator to supervise the inspection from the ground. Compared to other solutions developed for bridge inspection, our solution is able to maintain contact while moving across the inspection surface and is even capable of maintaining contact with two surfaces in corners, allowing the inspection of difficult-to-reach zones like bridge bearings. We describe the design and build process, the dynamic model and the control of the system proposed. We show the capabilities of the fully-actuated platform by indoor flights, while the proposed aerial platform is tested in a real scenario, for bridge beams and bearings inspection. The results of field tests demonstrate the feasibility and effectiveness of the proposed platform for bridge inspections.