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Acrobatic quadrotors play catch with sticks

In their latest trick, these flying platforms show off some amazing balancing skills.

Tim Hornyak
Crave freelancer Tim Hornyak is the author of "Loving the Machine: The Art and Science of Japanese Robots." He has been writing about Japanese culture and technology for a decade. E-mail Tim.
Tim Hornyak
2 min read
ETH Zurich

Can you toss a pole by its tip and catch it by the other end? These flying quadrotors can.

Researchers at ETH Zurich posted a video showing two quads tossing a pole in midair.

Dario Brescianini and colleagues at ETH Zurich's Flying Machine Arena developed algorithms for the game based on a 2D mathematical model of the ideal trajectory.

To test the model, the machines were fitted with 4.7-inch circular plates that they used to both throw and catch the pole, which was fitted with flour-filled balloons at the tips to act as shock absorbers.

The startling stunt is seen in the vid below. The quadrotors pull it off nicely, even when one of the balloons blows up at 1:34.

Interestingly, one of the algorithms allows the machines to learn and correct their mistakes.

"The biggest challenge to get the system running was the catching part," Brescianini is quoted as saying by colleague Markus Waibel on Robohub.

"We tried various catching maneuvers, but none of them worked until we introduced a learning algorithm, which adapts parameters of the catching trajectory to eliminate systematic errors."

The catch game builds on previous Flying Machine Arena tricks including balancing a pole and playing catch with a ball.

What's next for these high-flying performers? I think they could add a little excitement to Cirque du Soleil shows.