Unmanned aerial and traversing vehicle -- A mobile platform for bridge inspections

“Unmanned aerial vehicles (UAVs), also known as drones, have been rapidly growing in popularity since their creation. This study aimed to create a robotic platform used to assist in the inspection process of the nation’s aging and deteriorating bridges. To this end, a multimodal inspection robot that utilized both flying and driving technologies, was designed, analyzed, and tested for aerial, traversing, and their transitional operability. The design, herein referred to as the “BridgeBot”, was evaluated both computationally and experimentally. A finite element model of the BridgeBot was established and analyzed under static loading scenarios to help determine stress distributions and locate areas of concern. The prototype BridgeBot was then tested in the laboratory to evaluate the drone structure and ability to perform to its design intent. During a bridge inspection, the BridgeBot would deploy as a multirotor UAV and fly to the underside of a bridge girder. It would then utilize its specifically designed clamping system with custom rollers to engage and traverse along the girder flange. This transition from flying to traversing mode may not only significantly save battery, making it feasible for the BridgeBot to operate for longer periods of time, but also provide a stable platform for various cameras and nondestructive evaluation devices to acquire quality data. Although the design focused on steel girder bridges, it may later be adjusted for concrete girder bridges. Initial test results indicated the feasibility of the BridgeBot to transition from flying to traversing mode. However, upon landing, some of the electrical wires secured to the bottom of the flexible rotor arms were detached due to significant arm deformations causing the propellers to dislodge the wire connection under impact loading”--Abstract, page iii