mjog's profile - activity

Yes, it is. To clarify, it is not a problem that the models keep on moving, rather they start rolling of their own accord when stopped.

Wheeled models have a tendency to slowly roll when not subject to any other force (i.e. by a plugin driving the wheels). I have noticed this with both a URDF Segway-with-casters model and a URDF quad wheeler. I assume the problem is due to noise when calculating contact between the wheels and the ground.

I just worked-around the problem in a diff-drive plugin (based on the ROS erratic diff-drive plugin) in the same way DRC pins joints: When the wheel velocity is set to zero, I zero the wheel joint velocity then insert a static link between the wheel and the world, then remove it when before setting the wheel joint velocity to non-zero.

However this feels like a nasty kluge. Is there any better way of doing it? I was hoping for a model::Joint::setStatic(bool) method or something, but can't seem to find anything like that.

Is there any documentation of what I assume is the pre-SDF 1.0 Gazebo XML configuration format? The one with XML namespaces like xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller" and so on.

I have some old models that I need to understand and update that use this format.