Publish Joint forces

[Fixit-Davide]

🦟 Bug fix

Fixes #883

Summary

These changes should allow to obtain information regarding the forces applied to the joints.

Test it

• Pull gz-physics PR: [featherstone] Publish JointFeedback forces. gz-physics#628
• Launch gz sim --physics-engine gz-physics-bullet-featherstone-plugin lift_drag.sdf simulation.
• Send a command to the model (gz topic -t "/model/lift_drag_demo_model/joint/rod_1_joint/cmd_force" -m gz.msgs.Double -p "data: 0.8").
• Echo the topic: gz topic -e -t /world/lift_drag/model/lift_drag_demo_model/joint_state

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[ahcorde]

do you mind to sign the commit ?

[azeey]

Also, can you please add a test?

[Fixit-Davide]

I have just made a PR in gz-physics in order to populate the force fields while using bullet-featherstone. I added some information on how to test the code there (I have reported them here also).

[iche033]

looks good to me

[iche033]

Also, can you please add a test?

oh just saw that a test was requested.

waiting for a test to be added

[iche033]

CI warning:

"gz/sim/components/JointForce.hh" already included at /github/workspace/src/systems/physics/Physics.cc:119  

[azeey]

@Fixit-Davide we are now in Feature freeze for Gazebo Ionic. Since PR is already open, I've applied the beta label which means it's slotted for the Ionic release if we can get it merged before 08/28/2024. Do you think that's feasible? If not, please let me know and I'll remove the beta label.

[azeey]

To focus our efforts on the Ionic release, I'll go ahead and remove the beta label from this. I encourage you to respond to the feedback, but we'll hold off from merging this until Ionic is released.