ToF-based Simultaneous Localization and Mapping using a Shelled-UAV for Penstock Applications

Inspection of penstocks have posed a great threat to human personnel as it can be hazardous while doing manual inspections. In recent years, there is a rise in popularity in the use of Unmanned Aerial Vehicles (UAVs) for several applications including infrastructure inspection since it can help ease the risk of human accidents in doing such operations. With the addition of a shell to the UAV, it has been proven to be an efficient and effective way for the visual inspection of infrastructures and other related applications. In this paper, the concept of Simultaneous Localization and Mapping (SLAM) has been implemented to the system for the inspection of hydroelectric power plant penstocks by utilizing multiple state of the art Time-of-Flight (ToF) LiDAR sensors and an Inertial Measurement Unit (IMU) for the mapping and positioning of the shelled UAV inside the infrastructure. The experimental data obtained after conducting a test flight inside a mock-up penstock has been analyzed and interpreted to verify if the generated map is precise and accurate. With the proper positioning of the system and the correct map of the penstock, this innovation bestows a great breakthrough in visual inspection of infrastructures specifically the inspection of penstocks.