Coefficient of Friction Testing

[JVN]

Originally Posted by DonRotolo

John,

We don't calculate the CoF. If we need to know, we test relative to some other standard (i.e., another robot) by pushing it along carpet and measuring force - sometimes with 'calibrated legs' only.

Your method is valid for static friction, but dynamic friction is also important IMHO, since once you start moving the value is usually quite different from static friction (= Sticktion). To measure that in your test setup, you lift to just below your normal angle, set the robot sliding, then reduce the angle to where it stops. This was very important to us in Lunacy, for example, where the wheels were generally not at rest relative to the surface.

Don,
Do you have any of the data from the tests you've done, or any more info on how you take dynamic friction into account?

-John