Contact Area and its Relation to Friction?

[Guy Davidson]

Originally Posted by JesseK

PID Traction Control -- unless each wheel on a given side is indepedently driven from the transmission, what reliable way exists to tell the difference between wheel speed and robot speed? Being able to tell the difference in traction loss vs. the robot turning seems even more difficult to grasp.

I also don't understand the idea of PID traction control. I've heard of PID velocity control using encoders, and I'm planning to implement that on our robot this year, but I don't understand the idea of PID traction control. How would you do that?

Jesse, there are some ways. One way is to have a passive wheel on an independent axis in the center of your robot, and encode it. It will only move if the robot is moving. You could also use mouse sensors or trackballs to accomplish similar things, I think.