[ODE] Feedback from contact joints.. ?

[Nate W]

On Thu, 19 Jun 2003, Amund [ISO-8859-1] Børsand wrote:

> Hi, I'm trying to implement differentials in my car, and then I need
> to know how much resistance the wheels get from the ground. First I
> thought I could do this by getting the feedback from the wheel hinge
> (I'm currently using hinge2's with Fmax to rotate the wheels), but I
> need to know the resistance _before_ the wheel has turned.  So I
> thought what I needed was to know how much force the ground applies to
> the wheel.

Seems to me that the information you need will be present in the hinge
feedback.  

> Or maybe this doesn't solve my problem anyway?

For a differential, aren't you more interested in how much the wheel has
rotated, rather than how much force is on the wheel?  E.g. if one wheel
has turned .2 radians and the other has turned .3 radians, you know your
differential input shaft turned .25 radians, and the spider gear (if thats
the term?) allowed +/- .05 radians difference between the two.

-- 

Nate Waddoups
Redmond WA USA
http://www.natew.com