A CAM/AM-based trajectory generation method for aerial power plant inspection in GPS-denied environments

A wide range of inspection methods for large infrastructures including energy, transportation and defense sectors are available commercially. The use of UAVs (Unmanned Aerial Vehicle) for aerial inspection is one such technology that is growing popular due to its inherent ability to inspect inaccessible and hazardous locations safely and cost-effectively, reducing the downtime of the system being inspected. Computer Aided Manufacturing (CAM) and Additive Manufacturing (AM) are popular manufacturing technologies that have significantly progressed in recent years. The main difference between these methods is that one is subtractive and the other additive. However, the tools that operate to manufacture the parts go through the same set of coordinates, layer by layer, following a programmed path. In this paper, a novel method is introduced that uses a similar method to that of CAM and AM to generate UAV trajectories for GPS-denied environments. In this particular project, the trajectories are used for inspection of large structural components such as a power plant. This is an offline trajectory generation method that will enable UAV operation in areas of poor or no signal, for both internal and external inspection. Proximity sensors and anti-collision mechanism can be used in parallel as a fail-safe aid that may not be accounted for in an available CAD model.