For a continuous surveillance mission using a swarm of multiple tethered low-altitude long-endurance (LALE) multirotor-type unmanned aerial vehicles (UAVs), we developed a 500 W class photovoltaic power management system (PPMS) which monitors voltage and current flows of photovoltaic (PV) panels, battery pack, and UAV and controls power flows to support UAV flight operation. In contract to a fixed-wing UAV, a tethered multirotor UAV can generate continuously varying closed-circuit television (CCTV) like ground map images by stitching incoming images though the operation range is limited. With an indoor flight experiment, we demonstrated the usefulness of the PPMS and proved operation integrity. According to the results, a total of six multirotor UAVs were required to continuously perform a surveillance mission for 5 h 46 min from 11:04 to 16:50.
Aerial Surveillance with Low-Altitude Long-Endurance Tethered Multirotor UAVs Using Photovoltaic Power Management System