[ODE] CFM, ERP, stepsize, bNormalizationResult failed

Jon Watte (ODE) hplus-ode at mindcontrol.org
Wed Nov 21 10:25:00 MST 2007

If your robot falls through the ground when the ground is a plane geom, 
you're definitely doing something wrong. In fact, with 0.005 step size, 
the robot shouldn't fall through the ground even with a trimesh geom.

Your problem may be somewhere else, rather than the ERP/CFM values.


			/ h+

ode at thoemsen.ch wrote:
> Thanks for the help.
> I know that ODE can't simulate perfectly stiff joints but the deflection of the
> suspension is way too big. My rover is similar to NASA's rocker-bogie type
> (Spirit/Opportunity, Sojourner, etc.) but with a more complex suspension
> mechanism. To describe what happens in my simulation, imagine the Mars rovers
> on a horizontal plane (initial state) but the body has a pitch angle of several
> degrees because of the deflection of the suspension.
> Do you think the reason why I can't set my CFM value smaller could be related to
> redundant joints in my system?
> By the way, I have another problem: if I set gravity to 9.81 my robot falls
> through the ground. Initial position of the robot is about 10cm above ground
> and it weighs about 35 kg. Any ideas on that? 

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