Proof of Concept for Using Unmanned Aerial Vehicles for High Mast Pole and Bridge Inspections

Bridges and high mast luminaires (HMLs) are key components of transportation infrastructures. Effective inspection processes are crucial to maintain the structural integrity of these components. The most common approach for inspections is visual examination by trained and experienced inspectors. A proposed approach to assist inspectors during the visual inspection process is to use small unmanned aerial systems (sUAS) equipped with high-definition cameras to transmit video data of structural components in near real time. The use of sUAS as tools for structural inspections can significantly reduce costs and safety risks associated with inspectors and motorists, and improve the effectiveness and accuracy of structural health evaluations. Following a systems engineering approach, a proof-of-concept initial study was conducted to identify system limitations and gain insights into the expected usefulness of sUAS as tools for structural inspections. Extensive indoor controlled experiments using industrial fans were conducted to evaluate sUAS flight response in controlled wind conditions, to measure image quality in different flight scenarios, and to determine image quality in low-light conditions. Altitude, payload, and maneuverability tests were conducted to understand sUAS performance and limitation parameters related to their use for transportation infrastructure inspections. In full coordination with Florida Department of Transportation (FDOT), limited field tests were conducted to collect image data of underside bridge sections and HMLs. The collected images were of similar quality than those collected by inspectors during previous inspections. In addition, a basic sUAS flight training program was developed, and a preliminary cost analysis was conducted to estimate the cost for using sUAS as tools during inspections. Preliminary results showed potential cost savings in man-hours by using an sUAS approach instead of conventional methods. Overall, results provided evidence that significant benefits can be obtained from using sUAS during bridge and HML inspections. However, there still exist gaps that need to be addressed in order to use these aerial systems safely and effectively in practice. Various future research areas are identified to close these gaps and increase the general understanding of sUAS for structural inspections.