Sara Reardon, reporter
It's only a matter of time before robots start running away to join the circus. This "blind" robot - it has no visual sensors - can juggle a ball flawlessly and never gets tired. Designed by Philipp Reist and Raffaello D'Andrea of the Swiss Federal Institute of Technology Z?rich, the juggler uses only mechanical sensors on its paddle to detect the ball's trajectory.
To prevent the ball from flying off in any direction, the paddle is slightly curved. Each time the ball hits it, the robot calculates nine different aspects of the ball's bounce, such as its speed, angle, and spin. The paddle then either speeds up or slows down as it moves to meet the ball, thus keeping it bouncing in a stable arc.
The researchers tried out several different balls such as industrial ball bearings and tennis balls. Nylon balls worked the best, with the robot juggling them as high as 2 metres into the air.
But circus performers and buskers might not need to worry about their jobs after all. The researchers also discovered that the robot is very bad at juggling shoes and Coke bottles - both simple tasks for a human. Well, one who can juggle, anyway.
Journal reference: IEEE Transactions on Robotics, DOI: 10.1109/TRO.2012.2205493