Error:[/ActionGraph]Prim is not an articulation ros2_publish_joint_state ROS2PublishJointState(omni.isaac.ros2_bridge)

[wang_911205]

when I run the demo ROS2 Joint Control: Extension Python Scripting — Omniverse IsaacSim latest documentation
the ROS2PublishJointState node error

[hijimasa]

I think the document is not updated.
According to this document, the articulation root/targetPrim may not be /panda.

Enhancements to URDF Importer Articulation in Version 2023.1.1 Ensure Consistent Root Link Designation for Improved Simulation Accuracy

Up until version 2023.1.0, the URDF importer assigned the ArticulationRootAPI to the top-level prim of the articulation structure. The root link was then identified by PhysX through an analysis of the kinematic tree. This practice was revised in version 2023.1.1, whereby the ArticulationRootAPI is now directly associated with the actual root link. For example, in version 2023.1.0, when importing a Franka URDF, the ArticulationRootAPI would be placed on /World/Franka, and PhysX might designate an…

[wang_911205]

So ROS2 Publish Joint State node to publish ROS2 Joint States to the /joint_states topic
the targetPrim is not /panda？I change to /panda/root_joint or /panda/panda_link0 still report the error. can you give any suggest?

[hijimasa]

Is there a prim called base_link or link_0 under panda?
I don’t have an execution environment at hand right now, so I can’t give you a description here.
Could you put a screen shot to show all Prim?

[wang_911205]

[hijimasa]

Does /panda/panda_link0 have a articulation root property?

[wang_911205]

I tried still the eroor

[hijimasa]

This topic shows that articulation root is /franka_alt_fingers.

Corrections to tutorial: ROS2 Joint Control: Extension Python Scripting

I am going through Tutorial 7.2.10. ROS2 Joint Control: Extension Python Scripting. At the step “7.2.10.3. Add Joint States in UI”, points 4 and 5 instruct to select /panda as the articulation root. In the current version of Isaac Sim (2023.1.1) the Franka Emica articulation is at the root prim /franka_alt_fingers. So the tutorial description needs to be changed. Here is the link to the tutorial: https://docs.omniverse.nvidia.com/isaacsim/latest/ros2_tutorials/tutorial_ros2_manipulation.html#…

But the Prim is not exist, is it?
I will try the demo later.

[wang_911205]

@hijimasa

/franka_alt_fingers

I can not found /franka_alt_fingers,
You can try this demo and give me a reply later.

[hijimasa]

I can use it by /panda.
Can I check which USD file is used.
I use omniverse://localhost/NVIDIA/Assets/Isaac/4.1/Isaac/Robots/Franka/franka_alt_fingers.usd.
How about you?

[wang_911205]

I change to omniverse://localhost/NVIDIA/Assets/Isaac/4.1/Isaac/Robots/Franka/franka_alt_fingers.usd and targetPrim rename to /franka_alt_fingers It can normal run.

[hijimasa]

Please find “articulation root” from each Prim.
Any Prim should have an “articulation root” in Property.

[wang_911205]

usd_file.zip (3.0 MB)
My franka usd file the /panda/root_joint is articulation root. and targetPrim rename to /panda/root_joint What went wrong?

[hijimasa]

Indeed, the USD file I received did not work, and I was able to get it to work by moving the “articulation root” to panda_link0.
Frank_Robot_Graph-2.zip (3.0 MB)

[wang_911205]

I try the Frank_Robot_Graph-2 it work. Thanks.