My father impressed me, as a child, juggling 3 objects, then 4, then 5, and finally 6. I capped out at 3 trying to teach myself. The speed at which one needs to move for 5 and above takes much effort and time to master. At least for a human being.
A team of students developed The Juggler, a robot capable of handling 5 objects with no problem. Students, Jan Pšenička and Tomáš Němec, developed over 2 masters thesis's at the Department of Control Engineering at Prague’s Czech Technical University. The overall device is controlled with two vertical servo motors, and horizontal actuators using standard motion control principles. Circular "grippers" catch and move the billiard balls and is capable of tossing the ball over to the other gripper. An additional apparatus is used to pick up fallen objects and re-launch them. A high-speed camera is mounted in the front to watch the objects, billiard balls in this case, move is 3D space. A Kalman filter, in the driving software, handles the random variations in location prediction. The entire system is to operate without human intervention. The team put one additional requirement on the Juggler, it has to be controlled remotely via a Ethernet Powerlink over the internet.
So much technology had to be used to reproduce what my father, and people throughout the ages, could do with a little practice. The last addition to the Juggler should be a little showmanship.
Eavesdropper