Kiwi Drive Concept

[Ginger Power]

Originally Posted by Alan Anderson

In general, three wheels will always be touching the floor no matter what angle they are at. The two reasons I see for using the nearly flat angle are 1) it lowers the center of mass, and 2) it moves the contact point outward just a little more from the center of the robot.

Both were design considerations. A third consideration was that the geometry of a sideways omni wheel made it easy to "retract" the omni wheel using the pneumatic cylinders shown. When the omni wheels are retracted the robot rests on a singular contact point extending down from the frame presumably covered in rough top tread.

The idea is that each omni wheel can be retracted independently, giving the robot the ability to change its center of rotation about each pivot point. There's also the advantage of retracting all omni wheels when in scoring position so the robot becomes difficult to move.

[MikeE]

Originally Posted by Ginger Power

The idea is that each omni wheel can be retracted independently, giving the robot the ability to change its center of rotation about each pivot point.

...Kinematic calculations are left as an exercise for the student...

[Ginger Power]

Originally Posted by MikeE

...Kinematic calculations are left as an exercise for the student...

Ironic that you say that just as I'm leaving my last dynamics class of the year... but I agree!