Wheelslip plugin parameter addition

[knmcguire]

🎉 New feature

Helps with #1845

Summary

Adds parameter change functionality using the gz param to the wheel slip system plugin. This is in preparation to be able to write a working tutorial that is described in this #1845. This PR is based on the associated branch of that issue namely ign-gazebo6...ivanpauno/parameters-component-wheel-slip-demo6 from @ivanpauno but adjusted for gz-sim8

Test it

I've based these instructions on the instructions given in #1845 by scpeters adjusted to gz-sim8

Launch the trisphere cycle world

gz sim trisphere_cycle_wheel_slip.sdf

Another parameter check out the available parameters:

gz param -r /world/wheel_slip -l

Expected outcome

Listing parameters, registry namespace [/world/wheel_slip]...

systems.wheel_slip.trisphere_cycle1.wheel_front            [gz_msgs.WheelSlipParametersCmd]
systems.wheel_slip.trisphere_cycle1.wheel_rear_right            [gz_msgs.WheelSlipParametersCmd]
systems.wheel_slip.trisphere_cycle0.wheel_rear_right            [gz_msgs.WheelSlipParametersCmd]
systems.wheel_slip.trisphere_cycle1.wheel_rear_left            [gz_msgs.WheelSlipParametersCmd]
systems.wheel_slip.trisphere_cycle0.wheel_rear_left            [gz_msgs.WheelSlipParametersCmd]
systems.wheel_slip.trisphere_cycle0.wheel_front            [gz_msgs.WheelSlipParametersCmd]

Get the parameter of one of the wheels of the tricycles

gz param -r /world/wheel_slip -g -n systems.wheel_slip.trisphere_cycle1.wheel_front

Expected outcome

Getting parameter [systems.wheel_slip.trisphere_cycle1.wheel_front] for registry namespace [/world/wheel_slip]...
Message (gz.msgs.WheelSlipParametersCmd) was retrieved with non-fully qualified name. This behavior is deprecated in msgs10
Parameter type [gz_msgs.WheelSlipParametersCmd]

------------------------------------------------
slip_compliance_lateral: 1
slip_compliance_longitudinal: 1
------------------------------------------------

Set one parameter to a different number:

gz param -r /world/wheel_slip -s -n systems.w
heel_slip.trisphere_cycle1.wheel_front -t gz_msgs.WheelSlipParametersCmd -m "
  slip_compliance_lateral: 1
  slip_compliance_longitudinal: 2"

Expected outcome

Setting parameter [systems.wheel_slip.trisphere_cycle1.wheel_front] for registry namespace [/world/wheel_slip]...
Parameter successfully set!

Check the parameter again:

gz param -r /world/wheel_slip -g -n systems.wheel_slip.trisphere_cycle1.wheel_front

Expected outcome

Getting parameter [systems.wheel_slip.trisphere_cycle1.wheel_front] for registry namespace [/world/wheel_slip]...
Message (gz.msgs.WheelSlipParametersCmd) was retrieved with non-fully qualified name. This behavior is deprecated in msgs10
Parameter type [gz_msgs.WheelSlipParametersCmd]

------------------------------------------------
slip_compliance_lateral: 1
slip_compliance_longitudinal: 2
-----------------------------------------------

Remaining Questions.

I've put the PR into draft for now as there are a couple things to solve first or what I need help with:

• Solving the issue associated to this: Message (gz.msgs.WheelSlipParametersCmd) was retrieved with non-fully qualified name. This behavior is deprecated in msgs10
• Try/Catch if parameter doesn't exist. This was the case in the associated branch (ign-gazebo6...ivanpauno/parameters-component-wheel-slip-demo6) if issue Write a tutorial about using transport parameters with systems #1845 , but now the parameter value is gotten in a different way. But it should be handled somehow...
• Decide if we want to accommodate with a tutorial? I know this was started by @Gaurang-1402 in Add Tutorial on Using Transport Parameters with Systems osrf/gazebo_tutorials#175 but this was on the wrong location (also it doesn't work currently) but I don't like to take away work of others. But if you are okay with it I can add a tutorial here.
• There was a TODO that I retained from @ivanpauno that we need to see if that is still happening: // TODO(ivanpauno): WHY THE SCOPED NAME CHANGES BETWEEN HERE AND // ConfigureParameters()? // Here the scoped name starts with "wheel_slip." // In `ConfigureParameters()` that doesn't happen

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• 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.

[azeey]

@knmcguire just a heads up...since we are in feature freeze you'll probably not get a review on this for a while. We really appreciate you creating the PR and I hope you can wait to iterate on the PR till then.

[knmcguire]

@azeey Oh yes no worries I was aware and as you see there are still things to fix before this PR is ready to be properly reviewed and merged. I was just in a flow of implementing the params and see this also as a way to show people how to implement parameters as a plugin (or perhaps how not to do it if I did it completely the wrong way 😄 ).

I'll rework this a bit and once the freeze is over I can mark it ready

[azeey]

Sounds good. Thanks!

[scpeters]

thanks for opening this draft PR; I was just looking at this demo branch as well

[scpeters]

Deleting this line removes the ability to set wheel slip parameters via the ECM. I think it would be better to keep the ECM support (since it is more deterministic) but to add the gz-transport parameters interface in addition to it

[knmcguire]

Ah awesome. It's still in draft since I wanted to wait for the dust to settle of all the tutorial partying 🥳

Once i'm back from my holidays next week I'll look into making the PR more final. @scpeters if there are any of the remaining questions that I've noted in the first post that you can give some pointers for to solve then that would help me out quite a bit 😊

[knmcguire]

Hi, Just to let you know that I'm aware of this PR still being open but due to other priorities I just didn't had the time to continue and finish it off. I should have a good couple of months of free time where I could work on finishing this up. Sorry for the delay!