Interested in ROS2 wrapper code?

[mjeronimo]

Davide, I am currently working on splitting out ROS2 BT-related code from the Navigation2 project into a separate repository. I noticed your BehaviorTree.ROS project and wondered if perhaps we should collaborate on this. I have wrappers for ROS2 services and actions as well as a few additional general purpose nodes. Several sample programs are included as well. If you're interested, please take a look and let me know what you think: https://github.com/mjeronimo/ros2_behavior_tree. I'm looking for a place to host this code as well as it won't be under navigation. Also, I plan to use the repo to facilitate BT-based integration of navigation, grasping, and other capabilities.

[facontidavide]

Yes, I would love to collaborate. I will have a look

[mjeronimo]

Great. There are just placeholders for docs so far. I wanted to get your input first before investing the time on elaborating the docs. I'm currently working on unit tests for the nodes. The sample programs are complete.

[peterpolidoro]

Thank you both for such awesome libraries! I am excited to use BehaviorTree.cpp with ROS 2 similar to Navigation 2 project. For years I have been trying to figure out a way to for scientists with little programming experience to be able to modify and run their experimental rigs built and programmed by engineers. I think your BehaviorTree XML files and GUI to modify them could be perfect for that.

I have been looking through the code on both and I am still trying to understand the proper way to combine BehaviorTree.cpp with ROS 2. Is there any more documentation or examples you can link to give a high level description of how BehaviorTree ports should get mapped to ROS 2 topics and services? Is the BehaviorTree interface the same as the RobMoSys interface? Perhaps I need to understand an even more general issue of how to best convert between a RobMoSys interface and a ROS interface. I want to know how best to write my ROS code so that it always works properly with your BehaviorTrees and maybe any RobMoSys models in general.

Once I understand more I am happy to help add to your documentation and examples or whatever would be useful for you. Thanks!

[mjeronimo]

@peterpolidoro That's great. I think Behavior Trees are an excellent way to achieve the separation you're looking for. I have split out the ROS2-specific Behavior Tree code from the Navigation2 repository here into this repo: https://github.com/mjeronimo/ros2_behavior_tree (the result has no navigation-related code). So far, I have provided several examples of how to use ROS2 Behavior Trees. Please have a look and let me know what you think. The library still needs some documentation, which I can do in the coming weeks. There are template classes for easily integration ROS2 service and action clients. We could continue to add ROS2-specific features to the library to integrate more functionality. For example, I intend to use the BT functionality for system bring-up and shutdown as well (lifecycle management).