These Drones Actually Built A Working Rope Bridge [Watch]

Making Quadrocopter History One Knot At A Time

Swiss researchers have fitted 3 custom made quadcopter drones with spools of rope, and used them to build the first ever full scale rope bridge.  This moves drones forward one more step in the evolution of robotic and aerial construction.

A series of computational tools were developed for this project that allowed simulation, sequencing, and structural evaluation of the bridge even before it was built.  Hey, it won’t hold a truck, but just imagine the possibilities!

Watch these drones in action below!

Using quadrocopters and some rope, researchers have woven together a bridge strong enough to walk across. Made at the ETH Zurich Flying Machine Arena in Switzerland, the bridge joins two scaffolds, and is the first full-scale load-bearing structure autonomously built by flying machines. The feat represents one more step in the field of robotic aerial construction.Aerial Construction A collaboration between the Institute for Dynamic Systems and Control and Gramazio Kohler Research, ETH Zurich, 2015. The rope bridge is strong enough to walk across.

Except for the metal scaffolding at either end of the structure, the bridge itself consists exclusively of Dyneema rope, a tensile material with a low weight-to-strength ratio that makes it ideal for aerial construction. Weighing just 7 grams per meter, a 4 mm diameter Dyneema rope can sustain up to 1300 kg. The 7.4 m long bridge uses various rope techniques – knots, links and braids  – and has a total rope length of about 120 m.

How it works

The project was developed at the Flying Machine Arena, a research and demonstration platform for aerial robotics. The arena is equipped with a motion capture system that provides vehicle position and attitude measurements for the small custom quadrocopters. An offboard computer runs the algorithms and sends commands out to the flying machines via a customized wireless infrastructure.

Before construction begins, the location of the scaffolding is measured and input to the system. Once the anchor point locations for the rope are known, all the connections and links of the bridge’s primary and bracing sections are — without human intervention — autonomously woven and secured into place by the quadrocopters, which are each equipped with a motorized spool that allows them to control the tension of the rope.
A quadrocopter equipped with a motorized spool for rope deployment.
A quadrocopter equipped with a motorized spool for rope deployment.

A plastic tube guides the rope to a release point located between two propellers. The system estimates the external forces and torques exerted on the quadrocopter by the rope during deployment, and takes this into account in order to ensure that the quadrocopters behave as desired.

Credits

Aerial Construction is a collaboration between the Institute for Dynamic Systems and Control and Gramazio Kohler Research at ETH Zurich, Switzerland, 2015.

Researchers: Federico Augugliaro, Ammar Mirjan, Fabio Gramazio, Matthias Kohler, and Raffaello D’Andrea.

Want to know more about this research project?  Check out their project websites:

Article and images thanks to to rbohub.org