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

Needs a hard floor.

[Animats]

It's a cute idea. It assumes a single point of contact with the ground, and thus requires a flat, hard floor. This is limiting.

The various "omni-wheel" designs, with wheels composed of little wheels arranged around a big wheel, have a similar problem. The size of the little wheels, not the big one, determines the terrain-handling limits of the vehicle.

1980s robots tried to do everything by wheel odometry. Back then, most of the software was too dumb to plan moves given steering limitations, so omnidirectional drives were popular. Robots got a lot better when people stopped building robots with complex wheels and no suspension, and went to more ordinary wheels with off-road type suspensions.

Re:Needs a hard floor.

[timothyb89]

It's a cute idea. It assumes a single point of contact with the ground, and thus requires a flat, hard floor. This is limiting.

I've worked pretty extensively with mechanum wheels - essentially omniwheels with the smaller wheels at a 45 degree angle to the main wheel. Arranging four of them provides the same degrees of freedom as the example shown with two of these HOG wheels. Mechanum wheels work well and move quite fast, and I've yet to see a surface where they don't work - but they're costly, heavy, and wear quickly, not to mention the pretty enormous power requirements. Because of these limitations, for hobbyist robotics, they're simply not practical.

For many of the smaller projects I've done, traditional drive systems were slow and not nearly as useful as an omnidirectional (3 DOF) system - and without the ability to easily use something like omniwheels or mechanum wheels due to various constraints, HOG wheels would be a godsend. They provide most of the benefits of the traditional omnidirectional drive systems with very few hitches - and you'd be surprised how often the hard and flat surface requirement isn't an issue (or, in many cases, applies to traditional drive systems as well).

Re:Thats looks great

[wagnerrp]

Would you paint them blue, with a big pod on the back for a person to ride in?

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.

Re:gimbaledl ???

[maxwell demon]

A gimbaledl is a pivotedled supportedl that allows the rotationedl of an objectedl about a single axisedl. Isn't that obviousedl? :-)

Re:Not Novel

[robot_love]

Wait, so you're telling me he just re-invented the wheel?