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Link '' is not known to URDF. Cannot disable collisons.

Computer is running 32-bit Ubuntu 16.04 LTS with kernel 4.15.0-74-generic and ROS kinetic. Issue is similar to https://github.com/ros-planning/moveit/issues/1355 however no concrete solution was ever posted for that issue, or the x-post on ROS answers. I have a urdf file with multiple elements to it, and it appears fine in the moveit setup assistant as well as the demo.launch file. However, when executing the move_group.launch file for the same urdf file, the following errors appear and the links with warnings do not appear in Rviz.

[ WARN] [1579894372.596788574]: Link 'dummy_bottom' is not known to URDF. Cannot disable collisons.  
[ WARN] [1579894372.596799760]: Link 'dummy_bottom' is not known to URDF. Cannot disable collisons.  
[ WARN] [1579894372.596807727]: Link 'dummy_bottom' is not known to URDF. Cannot disable collisons.  
[ WARN] [1579894372.596815135]: Link 'dummy_bottom' is not known to URDF. Cannot disable collisons.  
[ WARN] [1579894372.596822319]: Link 'dummy_bottom' is not known to URDF. Cannot disable collisons.  
[ WARN] [1579894372.596829754]: Link 'dummy_fingers' is not known to URDF. Cannot disable collisons.  
[ WARN] [1579894372.596839316]: Link 'dummy_fingers' is not known to URDF. Cannot disable collisons.  
[ WARN] [1579894372.596850298]: Link 'dummy_fingers' is not known to URDF. Cannot disable collisons.  
[ WARN] [1579894372.596858761]: Link 'dummy_fingers' is not known to URDF. Cannot disable collisons.

I have tried and created multiple different URDF files. In every one, the newly created objects are "not known" to the urdf.

The urdf with the links above is as follows:

<robot name="dummy_robotiq_gripper">  
  <!-- Gripper Base -->  
  <link name="dummy_bottom">  
  <!-- <origin xyz="0 0 0.1" rpy="0 0 0"/> -->  
    <visual>  
    </visual>  
    <collision>  
      <geometry>  
        <cylinder radius="0.038" length="0.05"/>  
      </geometry>  
    </collision>  
  </link>  
  <!--Gripper Fingers (accounts for open and close positions) -->  
  <link name="dummy_fingers">  
    <visual>  
      <geometry>  
        <box size="0.03 0.15 0.13"/>  
      </geometry>  
      <material name="">  
        <color rgba="0.1 0.1 0.1 1"/>  
      </material>  
    </visual>  
    <collision>  
      <geometry>  
        <box size="0.03 0.15 0.13"/>  
      </geometry>  
    </collision>  
  </link>  
  <!-- Base to Finger joint -->  
  <joint name="base_to_finger_joint" type="fixed">  
    <origin xyz="0 0 0.09" rpy="0 0 0"/>  
    <parent link="dummy_bottom"/>  
    <child link="dummy_fingers"/>  
  </joint>  
</robot>

Asked by brenhertel on 2020-01-24 14:56:27 UTC

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Answers

Is load_robot_description set to true in the planning_context.launch file of your moveit_config package? If not, are you uploading the robot description to the ROS parameter server before you launch move_group.launch, e.g. when launching your robot drivers?

If neither of those help, please post your moveit_config package and the one containing your URDF in your OP.

Asked by fvd on 2020-02-29 12:59:42 UTC

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