Gazebo world link

[mhubii]

The recent updates to the links (for dual arm support #189):

• Twist ROS 2 Controller & Link / Joint Prefix #213
• Rolling -> Humble backport #225

cause a missing connection to Gazebo world, see below:

iiwa_gazebo_tipple_1.mp4

Whilst quite interesting, it should be fixed.

[Hydran00]

Hi @mhubii, I had the same problem. I solved it by adding the world link and a joint from world to to the floating link.
I just added the following code here in the .xacro definition.

  <link name="world" />
  <joint name="$world_to_base" type="fixed">
      <parent link="world" />
      <child link="$(arg robot_name)_floating_link" />
  </joint>

I think gazebo need a world link in the urdf to understand how the robot is connected to the world. Maybe the world_robot_tf in gazebo.launch.py were ignored since world did not exist?

[mhubii]

hi @Hydran00 and thank you for the hint there. Happy new year!