A fully autonomous self-recharging drone system capable of long-duration sustained operations and inspections of power lines has been engineered by researchers from the University of Southern Denmark.

The commercial Tarot 650 Sport carbon fiber drone frame is fitted with an electric quadcopter propulsion system, a 7,000-mAh lithium-polymer battery, a Raspberry Pi 4 B microcomputer, a Pixhawk V6X autopilot module, plus a millimeter-wave radar unit and an RGB video camera. When onboard software detects that the battery is getting low, the aircraft uses its camera and radar to spot and approach the closest power line.

The autonomous drone recharges from a power line. Source: University of Southern Denmark

A passively actuated power line-gripper on top of the drone sits within a cable guide consisting of two widely spread inward-sloping arms. This mechanism grasps the powerline cable during landing after which a control circuit regulates the magnetic field inside a split-core current transformer to provide sufficient holding force as well as battery recharging.

During field tests on power lines at Denmark's HCA Airport, the 4.3 kg (9.5 lb) demonstrator drone was able to operate for over two hours, recharging its battery five times between line-inspection sessions. The developers plan to test the craft in more remote locations and in adverse weather conditions.

A paper describing this research will be presented at the 2024 IEEE International Conference on Robotics and Automation, scheduled for May 13 to May 17 in Yokohama, Japan.