Spider-drones weave high-rise structures out of cables

SPIDER-LIKE, the drone spools cable behind it as it zips between supports. It is weaving a structure high above where ordinary building equipment can easily reach.

This is construction as envisioned by roboticists and architects at the Swiss Federal Institute of Technology (ETH) in Zurich. As well as these web-like designs, the team is teaching drones to build towers from foam bricks.

Flying machines have an unlimited workspace – they can go anywhere, says Federico Augugliaro, who is leading the robotics side of ETH's Aerial Construction project. "There is no physical connection with the ground, so they can move construction elements to any location, and fly in and around existing structures."

Each quadcopter drone is equipped with a spool of strong plastic cable that runs out behind it as it flies. One end of the cable can be secured by making several turns around a pole. The drones are positioned and directed autonomously from the ground by a central computer fitted with a camera that watches them as they fly. For example, to loop cables around each other, the computer directs two drones to fly through certain points at an exact time. In this way, the fleet can tie complicated knots and form large, regularly repeating patterns strung between fixed structures.

Augugliaro's team revealed the work this week at a robotics conference in Tokyo, Japan.

"Something possible would be a structure like a bridge or a connection between existing buildings," says Ammar Mirjan, Augugliaro's counterpart on the architectural side of the project. Mirjan is working with the roboticists to help make sure their work will be useful for architecture and construction. "If you had skyscrapers, you could connect them," he says.

The drones could make building much easier, says roboticist Koushil Sreenath at Carnegie Mellon University in Pittsburgh, Pennsylvania. "You just program the structure you want, press play and when you come back your structure is done," he says. "Our current construction is limited, but with aerial robots those limitations go away."

The ETH researchers are not the only group writing drones into the future of construction. At the MIT Media Lab in Cambridge, Massachusetts, Neri Oxman and her team are using robots suspended on cables to build structures. And at the University of Pennsylvania, the General Robotics Automation Sensing and Perception Lab is using drones with robotic clamps to build towers of magnetic blocks.