How to creat gearbox joint in <gazebo> tag?
My robot need gearbox joints,but I cann't creat it in urdf file,so I want to use <joint> tag of sdf file in the urdf file by <gazebo> tag,and I reference this tutorial Using a URDF in Gazebo.The following code is written in a xxx.gazebo file and is included by a xxx.xacro file.
<gazebo>
<joint name="joint_DownGear_LeftMainRocker" type="gearbox">
<parent>DownGear</parent>
<child>LeftMainRocker</child>
<gearbox_ratio>1</gearbox_ratio>
<gearbox_reference_body>body</gearbox_reference_body>
<axis>
<xyz>1 0 0</xyz>
</axis>
<axis2>
<xyz>0 0 1</xyz>
</axis2>
</joint>
<joint name="joint_DownGear_RightMainRocker" type="gearbox">
<parent>DownGear</parent>
<child>RightMainRocker</child>
<gearbox_ratio>1</gearbox_ratio>
<gearbox_reference_body>body</gearbox_reference_body>
<axis>
<xyz>1 0 0</xyz>
</axis>
<axis2>
<xyz>0 0 1</xyz>
</axis2>
</joint>
</gazebo>
but it failed,there isn't the effect of gearbox in Gazebo simulation.So,there is anyone use gearbox joint like this.Please!Thanks!