Quote:
Originally Posted by Aaron Ng
i was thinking of powered ackermann as being difficult, because my gut tells me that unless most of the weight is in the front, when you turn the wheels, they will just slide and create friction, acting like a brake instead of actually turning. of course, cars do this, and they are fine, and this is my gut, and my gut is often wrong.
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That would only happen if you break traction on your front wheels, which mainly depends on:
-Your slip angle (i.e how much you turn the wheels relative to your overall velocity vector)
-normal load on the wheels (as long friction remains linear more normal load = more traction. Also don't forget that normal load can change due to weight transfer from acceleration)
-characteristics of your wheels (you want something with a lot of lateral traction capability, i.e definitely not omni wheels)
If you put less weight on your front wheels by shifting your CG rearward you will break traction at smaller slip angles, but you will also get more yaw moment at a given slip angle! Assuming your tractive capacity is entirely linear with normal force (this depends on your wheel characteristics and the magnitude of the normal force) it all cancels out and the position of your CG has no effect on your lateral acceleration!