Add friction to avoid joint slippage, specially in TIAGo

Author: Victor Lopez

pmb2_description/urdf/wheels/wheel.urdf.xacro

@@ -72,6 +72,7 @@ Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041
           <origin xyz="0 ${-separation / 2 * reflect} 0.0" rpy="${-90.0 * deg_to_rad} 0 0"/>
           <axis xyz="0 0 1"/>
           <limit effort="${torque}" velocity="${velocity / radius}"/>
+	  <dynamics damping="0.0" friction="10."/>
         </joint>
 
         <!-- Gazebo extensions -->