[ODE] Steering and rolling wheels

[Sergio Casas Yrurzum]

Hello everybody,

I'm working on a wheeled mobile robot with ODE and I'm having problems with
the wheels motion.

My robot consists of the robot itself and three wheels, one front
free-rotation wheel and two rear wheels that are (both) steering and rolling
wheels at the same time.

The front wheel is joined to the robot with a BallAndSocket Joint, and works
fine.

For the rear wheels I use a Hinge2 joint with the local wheel Y axis as
rolling axis, the local Z axis as steering axis, and local X axis as the
direction of wheel's linear displacement, and I use
AddRelTorque(0.0,Torque,0.0) to make it roll and
AddRelTorque(0.0,0.0,Torque) to make it steer.

It works really fine if I do ONE movement (steering OR rolling) AT ONCE, but
it causes jumping and rare motion when I make both movements at the same
time. In adition, when steering too fast it seems to behave as if it has a
stop limit. I tried to modify most of Hinge2 parameters (specially
FudgeFactor) with no improvements, but the FMax parameter seems to influence
a lot. What can be happening? Must I use another solution to this problem?
Another kind of joint?

Has anybody done something similar? If anyone has done a steering and
rolling wheel with ODE, his/her help would be very appreciated.

Thanks in advance.


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Sergio Casas Yrurzum
Real Time Graphics Group - ARTEC
Instituto de Robótica (Robotics Institute)
Universidad de Valencia (University of Valencia)
Polígono de la Coma, s/n
46980, Paterna, Valencia
España (Spain)

E-mail: scasas@robotica.uv.es
Web: http://robotica.uv.es/grupos/artec/English
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