What is a killough platform?

A Killough platform is one of the many types of holonomic drive trains -- it can move forward and backward as well as left or right without turning. A car is not holonomic because it has to turn in order to move left or right, but a Killough platform can move in any direction instantaneously.

The Killough platform is based on the same concept as Kiwi drive with 3 wheels offset 120 degrees from each other, but instead of using omni wheels (wheels with horizontal rollers on the side so they can slide left or right but be powered forward), the Killough design uses two regular wheels mounted sideways and turned 90 degrees from each other, effectively creating a basic omniwheel. The wheels rotate sideways from how they would usually (like if you took the wheel off a car and flipped it end over end) but since there are two of them rotated 90 degrees, there's always a tire contacting the surface, so the wheel continues to move forward. Since the wheels are sideways, you can push them in the same direction as would normally be forward without resistence.

The Killough platform was invented by Stephen Killough in 1994 while working at Oak Ridge National Laboratory on omni-directional drive platforms.