Question regarding ROS2 and /robot_description assembling

[julianmueller]

Dear @arounamounchili ,

Im a researcher in the field of robotics and I just stumbled across this repo, as I was developing my own urdf/xacro parser library (currently still a private repo). My goal is to have some kind of a python library I can use to "dynamically" assemble urdf/xacro files. The question is, whether this project goes in the same direction, and if I can contribute here, or if my usage idea is out of the scope of this library.

My use case is as follows:
I have several industrial robots (mostly URs), each with different endeffectors and camera systems, which I switch regualarly using a tool changer. The means, I'm developing xacro macro files for all components that are attached to the robot flanges (adapters, cameras, tool-changer, tools). Doing this manually is cumbersome, especially when it comes to passing all the arguments around, dealing with global arguments like "use_sim" etc. All-in-all, having xacro macros for all of this is a huge pain. And I havent even mentioned srdf files, which im also assembling using xacro macros, because with all the modular robot components, I need to disable many collisions, so moveit recognizes the robot as collision free and lets me move it.

My ideal solution would therefore be:
In my launch files, Im loading simple urdf and srdf files (maybe some xacro) into some kind of python data models. Then I use python functions (this repo, or my own) to assemble my robot with all its attachements and then pass the resulting urdf&srdf to the robot state publisher and moveit.

Also, it would be nice to have an "linkforge_ros" repo, which is listed in the ros index, and can be installed via eg "sudo apt install ros-jazzy-linkforge".

Would this be also in the interest of this repo? If yes, I'd be glad to contribute this, as your urdf and xacro parsing seems quite advanced and well tested. Please feel free to contact me.

Best regards
Julian Müller

[arounamounchili]

Hey @julianmueller ,

Thanks for reaching out and great timing actually.

Programmatic robot assembly and SRDF support are gaps I hadn't tackled yet, but your use case makes a strong argument for prioritising them next. They fit naturally into linkforge_core.

A linkforge_ros package for the ROS ecosystem is also already on my radar, the architecture was designed with exactly this kind of expansion in mind.

If you want to move forward, open an issue describing the API shape you have in mind. That's the best starting point to align before any code gets written. Happy to iterate quickly from there.

Arouna