Caster and force feedback

[LBodnar]

I have to piggyback on this thread because I can't open a new thread. It says "no post mode spcified" when I try to post.

I can't seem to find if caster provides an input to steering wheel force feedback.

It should be roughly along the lines of

Code:

Feedback = Mz - My * WheelRadius * sin(CasterAngle);

I have only found

Code:

Feedback = Mz

Caster is massively important in providing self-centering forces, Mz is OK but it will go to zero and even turn negative at some point.

I have no idea how to pull all data into one place - caster is defined in suspension, radius is in tire. All these definition scopes and other "::" nonsense! Plain C and FORTARN were the pinnacle of my high level languages skills before I slipped back into Assembly.

Anyway, I have hard- coded the caster details and it feels much better.


Update:
It's not exactly sin(CasterAngle) because this assumes that the wheel steering axis projection onto the wheel plane passes right through the wheel's centre. It should be caster distance but I don't know how to calculate it from suspension geometry. E.g. open wheelers usually have caster [distance] between 10 and 20 mm.