pic: steering methods

[gblake]

Originally Posted by GeoffP

it will also be your increase in acceleration if you can prevent your wheels from sliding either laterally or transversely.
static friction is intermolecular bonding between 2 stationary surfaces (even if one is rolling). dynamic friction is trying make those bonds while the surfaces are sliding plus includes momentum. they should be very different.
that being said, the ratio is much closer with some materials and especially at low friction so your testing may be correct. thanks for posting that.

All of this is nice for a machine that is rolling in a straight line (no changes in the orientation of its velocity vector, just changes in the magnitude); but since most of these discussions center around the notion of using "traction control" during turns...

Just as soon as one of these slippery wheels is rotated (about a vertical axis) to try to turn a bot, I assert that the wheel has to begin slipping sideways; and further I assert that it will continue to slip sideways until the dynamic (NOT static) friction forces between the wheel and the floor wipe out the bot's forward velocity.

If I am right, then no amount of traction control attempts made after a wheel is turned will put the wheels back into the static friction domain until the bot's forward (its pre-turn direction) motion is gone. Once that forward motion is gone and the wheels are no longer skidding sideways, traction control can then help move the bot in its new direction.

Alternatively, traction control could be used to slow a bot before a turn is attempted. Doing that would minimize the time spent slipping sideways after a turn is begun, but it wouldn't do much to help you run away from a pursuing bot if you are trying to do some evasive maneuvering.

Am I overlooking something? If traction control isn't very valuable, I would hate to see teams invest more into it than is appropriate.

Blake