[ODE] Re: Car Braking Problem

[Matthew D. Hancher]

> When i brake (dBodyAddTorque), the car turns to the right or to the 
> left
> depending on the Y Axis Angle.

Perhaps this is a product of ODE's friction model, which is simplified
in ways that make it anisotropic.  You can address this somewhat by
cleverly setting the contact's friction direction, rather than letting
ODE pick it arbitrarily.  When you generate each contact joint between
a wheel and the ground, set the fdir1 field of the dContact structure to
be a unit vector that is in the direction of horizontal motion of the
wheel geom, and set the dContactFDir1 bit in the contact flags.

Matt

Matt Hancher
Intelligent Systems Division
NASA Ames Research Center
mdh at email.arc.nasa.gov