Dear people,

I do have a mobile robot with four rolling steerable wheel either in Xacro or URDF.

I have the baselink and a wheel link I also have the joint where the parent is the baselink and the child is the wheel.

The axis is: <axis xyz="0 1 0" rpy="0 0 0" /> which type is continues so the wheel can rotate freely around the Y axes.

However I want also the wheel to rotate freely in the Z axis. for that I had added an extra joint wchi parent is also the baselink and the rotation is in the Z direction <axis xyz="0 0 1" rpy="0 0 0" />

The problem I do have is the the wheel only rotates around the Z axes and not the Y axes.

I do not know if it is possible to have a wheel that can rotate independently in both axes, Y and Z.

I am looking forward to your replay.