[Graceful Controller] Add deceleration limit

[SakshayMahna]

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Basic Info

Info	Please fill out this column
Ticket(s) this addresses	#4865
Primary OS tested on	Ubuntu
Robotic platform tested on	Turtlebot3 Gazebo Simulation
Does this PR contain AI generated software?	No
Was this PR description generated by AI software?	No

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Description of contribution in a few bullet points

Graceful Controller makes use of a slowdown radius to stop at the target. This PR additionally applies deceleration limit while the robot is stopping.

Description of documentation updates required from your changes

• Added new parameter, deceleration_max to Graceful Controller.
• Supporting a new behavior for stopping.

Description of how this change was tested

Tested in simulation.

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Future work that may be required in bullet points

For Maintainers:

• Check that any new parameters added are updated in docs.nav2.org
• Check that any significant change is added to the migration guide
• Check that any new features OR changes to existing behaviors are reflected in the tuning guide
• Check that any new functions have Doxygen added
• Check that any new features have test coverage
• Check that any new plugins is added to the plugins page
• If BT Node, Additionally: add to BT's XML index of nodes for groot, BT package's readme table, and BT library lists
• Should this be backported to current distributions? If so, tag with backport-*.

[SakshayMahna]

@SteveMacenski
Opened the PR as discussed.

A few points to note on the implementation:

• I modified the existing calculateRegularVelocity and calculateNextPoint functions in the Smooth Control Law file. There is only one dependency to the package nav2_docking. Instead of modification of the existing function signature, I can implement a new function altogether.
• This PR is touching nav2_docking package as well, which now also requires the decleration_max parameter.

[SteveMacenski]

Also check out the CI tests, a few are legit failing it looks like from this update

[SteveMacenski]

@SakshayMahna any update? I see you pulled in main

[SakshayMahna]

No not yet. I will get it done by this week.

[SteveMacenski]

Ping me when you want a review :-)

[codecov]

Codecov Report

❌ Patch coverage is 97.50000% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
nav2_graceful_controller/src/parameter_handler.cpp	80.00%	1 Missing ⚠️

Files with missing lines	Coverage Δ
...e/nav2_graceful_controller/graceful_controller.hpp	100.00% <ø> (ø)
...ude/nav2_graceful_controller/parameter_handler.hpp	100.00% <ø> (ø)
...v2_graceful_controller/src/graceful_controller.cpp	89.47% <100.00%> (+0.12%)	⬆️
...av2_graceful_controller/src/smooth_control_law.cpp	100.00% <100.00%> (ø)
nav2_graceful_controller/src/parameter_handler.cpp	99.29% <80.00%> (-0.71%)	⬇️

... and 4 files with indirect coverage changes

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[SteveMacenski]

Is this ready for a review yet? :-)

[SakshayMahna]

Hi @SteveMacenski
Ready for review. This currently keeps the functions used by nav2_docking untouched. The deceleration is only being applied when the graceful controller is being used.

[SakshayMahna]

Single constructor for Smooth Control Law now.
Initialised the same in docking as an INFINITE value, and mentioned in a comment.
Still kept the setter, for completeness.

[SteveMacenski]

How about std::numeric_limits<double>::max()? This is typically how we represent a large initialized value

[SteveMacenski]

Why the duplication for the calc velocity / next pose methods? I Think this falls into the same camp to remove the duplication of methods. Can we simply call a single implementation and in the docking have the field for that be some arbitrarily high value like INF / MAX?