Quote:
Originally Posted by cbale2000
For those of us who don't know, would someone mind explaining what a Wheel Spacing Ratio is and why it's relevant/important?
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I'm not sure I've seen this term before, but the idea seems to be the effective aspect ratio of the wheels which contact the carpet. A 4 wheel "tank drive" vehicle with normal (non-holonomic) wheels which is longer than it is wide will be unable to rotate or turn while driving because the lateral friction of the wheel on the carpet can generate more torque resisting the turn than the rolling friction can in creating the turn. This lateral friction is known as "scrub".
However, making all robots "wide" isn't effective either, as they tend to fall over backwards in hard acceleration or forwards in hard braking. The "drop center" drive is designed to give the best of both situations; a long wheel base for purposes of acceleration, and a short wheel base for purposes of turning (because the wheels which do not contact the carpet don't count, and wheels which carry less than their "fair share" of the weight count less than those which do when it comes to generating the scrub torque.
Quote:
Originally Posted by cbale2000
I'm also not entirely sure what I'm looking at on that chart, some additional labels would be nice imo.
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Yes. I'm not sure what "the assumptions" were to generate the rows, either.