MIT researchers propose power lines to recharge UAVs

By Patrick C. Miller | July 31, 2014

Researchers with MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) think they’ve found a solution to the problem of limited UAS range. 

Drawing inspiration from pigeons, they’ve developed a lightweight unmanned aerial vehicle (UAV) that can perch on a power line like a bird to recharge its onboard battery.

In a recent paper, CSAIL researchers said this development creates the potential for UAVs to recharge their batteries using the magnetic fields emitted by power lines. The ability to extend the UAVs range by recharging creates greater potential for commercial use, particularly for retail package delivery.

The CSAIL team’s single-motor glider has a complex control system that automatically directs it to slow down, tip its wings, and hook onto a line, even in moderate wind conditions. Where past versions required wall-mounted cameras and a separate computer, CSAIL’s has on-board sensors and electronics that can plan and execute moves in real-time.

Ph.D. student Joe Moore, wrote a paper on the project with former Ph.D. student Rick Cory and Russ Tedrake, an associate professor of electrical engineering and computer science, for the summer issue of Bioinspiration and Biomimetics. They came up with the idea of emulating a bird to improve UAV agility.

"It’s challenging to design a control system that can slow down a fixed-wing aircraft enough to land on a perch," Moore said. "Our strategy accomplishes this and can do so in outdoor environments using only on-board sensors."

They studied pigeons’ and eagles’ abilities to stall and how they flare their wings, angle their bodies and maintain velocity to accurately judge the trajectory needed to perch on a wire. Creating a computer model of the maneuver is far more complex than a conventional aircraft landing