URDF Importer Extension Error

Hi everyone,

I’ve been following a process to import a URDF file for the ABB IRB5400 robot (abb/abb_irb5400_support/urdf/irb5400.urdf at kinetic-devel · ros-industrial/abb · GitHub). I’m using the URDF Importer extension, similar to the steps shown in this tutorial: YouTube - URDF Importer Tutorial.

However, I’m encountering an issue that wasn’t covered in the tutorial. When I attempt to simulate the robot by pressing the play button, the robot doesn’t move (as in the youtube video). Instead, I’m greeted with the following warning message:

Invalid PhysX transform detected for /World/abb_irb5400/tool0

I checked for any nan values in the transformation matrix as stated here (Invalid PhysX transform detected - #2 by AlesBorovicka)
but they seem normal.

Has anyone else experienced a similar issue or have any insights on how to resolve this? Any advice or guidance would be greatly appreciated. Thank you in advance for your help!

Update:
When I disable the option “Parse Mimic Joint Tag” when using the URDF importer or set the parameter import_config.parse_mimic to False, the waring message disappears. But the robot still doesn’t move when starting the simulation.

FIX
Changing the drive mode of the joints from position to velocity and reducing the damping fixed the issue.

I’m using the 2023.1.1 Isaac Sim version.

2 Likes

The mimic joint in 2023.1.0 was implemented with TendonAPI in Physics. In 4.0 we implemented Mimic joints with a new MImic Joint API that more adequately conveys the gearing.