[ODE] RE: Calculating slip angle for a vehicle

[cgiscript at hotpop.com]

> Not quite. The vehicle may be rotating itself, this makes for a different
> wheel velocity for each wheel (if the car is changing heading, the left
> wheel will move forward faster than the right, or vice versa).

But you can get the wheel velocity vector directly for each wheel, not
derive it from the chassis (dBodyGetLinearVel(this_wheel);)

> Also, slip angle is based on the surface. So you have to project the wheel
> vectors to the surface (using the surface normal and the wheel side vector
> for example).

you use the chassis rot vector, and add the wheel stering angle
(dJointGetHinge1Angle1(this_wheel); make a rotation matrix and multiply to
simply create the wheel rot). then normalize the wheelVel vector
then you are right about dot these vectors and you get the cos of the
slipangle

hey, Ruud (you are RvG right ?) thanks a lot, i truly appreciate your
contribution

Andres
cgiscript at hotpop.com