Ballbot - ROBORAMA.info

Probably left over from the development and testing phase, to stop it from falling over and damaging itself.

Well, you sure are cynical. If you would bother to watch some of the other videos of the robot, you would find that it is for stabilizing and calibrating the sensors regarding the orientation and center of gravity of the robot while its balancing program is gearing up. The robot is purely experimental, and if you think everything experimental is useless, you have a dark view of the world, my friend.

I don't think it uses a gyroscope, at least I hope it doesn't. That would be less interesting, and make it more rigid and less flexible. It's better to just balance the way humans do - by shifting it's point of contact with the ground relative to its center of mass and its movement. It needs a "balance sensor" - something to determine which way it's tilting, and a good balancing algorithm, but I don't really see why it should be too difficult, at least not in theory.

It orients itself by shifting its center of gravity. It's top heavy, with the batteries and computers in the top, and the ball on the bottom acts as a wheel to move the bottom of the robot to just below the top of the robot, keeping it in perfect balance.