BUG: motor coordinates

[phmbressan]

Pull request type

• Code changes (bugfix, features)
• Code maintenance (refactoring, formatting, tests)
• ReadMe, Docs and GitHub updates
• Other (please describe):

Checklist

• Tests for the changes have been added (if needed)
• Docs have been reviewed and added / updated
• Lint (black rocketpy/ tests/) has passed locally
• All tests (pytest --runslow) have passed locally

Current behavior

A bug was identified by @Gui-FernandesBR regarding add_motor coordinate conversion. A legacy assumption of nozzle_position=0 was being considered in code.

New behavior

The coordinate conversion was fixed and now is consistent with the documentation: positions are defined with respect to the coordinate system's origin of the objects involved.

A parametrized test was added to check this behavior.

Breaking change

• Yes
• No

[Gui-FernandesBR]

Overall a simple and effective solution. I really liked it.

As this is a bug solving, I believe we should merge it directly to the master branch so we don't spend much time until actually getting these changes to the default branch.

[MateusStano]

I think there are still some things wrong thorought the code. Here is what I found:

• rocket_prints.py: Line 97,
• rocket.py: Line 102, documentation is wrong
• flight.py: effective_1rl and effective_2rl seem wrong
• flight.py: b and c parameters in u_dot
• flight.py: r_NOZ in u_dot_generalized
• flight.py: in b parameter of rotational_energy

Btw. The effective rail cached properties were duplicated, I just deleted them here because they are still related to this bug

[Gui-FernandesBR]

Approved again, good work here!