Novel Drive Wheel System Based On Spinning Sphere

An anonymous reader writes "A Bradley University student has built a mobile robot that uses a hemispherical omnidirectional gimbaled, or HOG, drive wheel. It consists of a black rubber hemisphere that rotates like a spinning top, with servos that can tilt it left and right and forwards and backwards. The HOG system delivers an amount of torque directly proportional to the tilt of the hemisphere, allowing the robot to move incredibly fast nearly instantaneously."

Comments

Not Novel

[mentil]

The video embedded in TFA contains the engineer who created this saying that it was invented about 100 years ago, but nothing came of it and the tech was forgotten. He did rediscover it independently, however.

1988 Toyota Olympic Ideas winner

[poodlediagram]

This has already been turned into a personal vehicle some years ago. It won the 1988 Toyota Olympic Ideas competition and ran on perpetually spinning Chinese woks. The best link I can find is

http://books.google.com/books?id=1M3e82yGmZMC&pg=PA27&lpg=PA27#v=onepage&q&f=false

Perhaps someone can find a better picture or video.

Say this thing hits a curb

[SmallFurryCreature]

Spinning top, you ever played with these toys? What happened to them when they hit a curb like a book or something? Right, they bounce off. Why? Because all of sudden it gains traction with what can be thought of as a wheel.

This ball wheel works as an infinite gear because by tilting it, the controller decides exactly how large a wheel (a ball is an infinite number of circles/wheels, each a bit smaller/larger then its neighbour, stacked on top of each other) contacts the floor. If the ball is spinning direction is parallel to the floor (if the ball doesn't deform) it wouldn't move because there is no forward motion. Tilt it and you are essentially making contact with an ever larger wheel. If the RPM remains the same, the larger the wheel the greater distance must be travelled. That it works is clear and predictable. It makes perfect sense.

But a bump on the road would suddenly cause a far greater wheel to make contact, greater wheel means greater speed and BAM, you got a difficult to control vehicle.

This thing doesn't just need a flat surface, it must also avoid any curbs. And what if it hits a crack in the surface, what if its gets grip on its on opposite sides of the spinning ball?

Doesn't mean this won't have its uses but they will be limited.