Quote:
Originally Posted by Kevin Sevcik
Madison,
You should put a CG marker on your sims, things get more interesting when you start looking at where your robot starts tipping, and where you end up after you tip.
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Given that my model is symmetrical in two planes, the CG is right in the middle. The robot will obviously behave differently going over the bump if the CG is very far forward or aft, but my model isn't complete enough to capture that yet.
8WD may send the robot "higher" on its way up the bump, but the same behavior that causes that also prevents the end of the robot from falling quite as far as it might on a 6WD system. I am under no illusion that the robot will ever stop successfully on the flat top of the bump and understand that it's going to dive hard into the ground on its way down in all cases, though.
It's also possible to implement 6 or 8WD systems wherein the wheels are not equidistant from one another and see some altered behavior from that. In 8WD, moving the center wheels closer makes the system begin to approximate a 6WD frame -- so it won't ride up as high while climbing, but falls correspondingly further on the trip down. It's all about trade offs, obviously, but I am more concerned with minimizing the force of the giant thud that'll happen on the way down than I am with tipping to 45* on the way up.