From IEEE Spectrum
May 31, 2011
UPDATE: The Czech roboticists updated their video with labels and a slow motion sequence, making it easier to see how the robot juggles three, and then four, and finally five balls, and also how it drops one ball at the end.
Robots are especially good at juggling. This is not to say that juggling is a particularly easy problem to tackle, because it’s not, but it’s a fun excuse to design a robot to demonstrate precision control and high-speed object tracking. The robot in the video above, for example, was built by three masters students from the Department of Control Engineering at the Czech Technical University in Prague. It uses three linear motors, including one for each arm and a third for a central ball deployment system, along with two pivoting “hands” to catch and toss up to five balls at once. The feedback loop is closed using data from encoders built in the motors, and a high-speed camera helps to fine-tune the trajectories of the balls.