FEAT: new actuator class for roll, throttle, and thrust vector control

[zuorenchen]

Pull request type

• Code changes (features)

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 tests -m slow --runslow) have passed locally
• CHANGELOG.md has been updated (if relevant)

Current behavior

• In ENH: Add Thrust Vector Control (TVC) #154, TVC feature is requested.
• Only air_brake is implemented as a controller

New behavior

• A new Actuator base class is added.

  • This class follows the implementation of air_brake
  • The actuator range can be clamped to limit
  • The actuator will be saturated to the rate limit (if the actuator demand_rate (a.k.a. sampling_rate) is discrete)
  • The actuator dynamics is modelled as a 1st-order low pass IIR filter (if the actuator demand_rate (a.k.a. sampling_rate) is discrete)

• Inheriting the Actuator base class are

  • throttle: an actuator that applies a throttle gain value on top of motor thrust.
  • roll: an actuator that applies a magic / hand-of-god roll torque on the rocket
  • thrust vector: actuators that gimbal the motor thrust vector on x and y axis

• New files:

  • actuator classes in new /actuator folder
  • prints for actuators
  • test_actuator (generated by copilot)
  • example applied on halcyon_flight_sim

• Modified files:

  • rocket.py: implement add_actuator methods
  • flight.py: apply actuators on the ODEs

known issue

• Throttling doesn't change the propellant mass flow. It is essentially throttling the ISP of motor.

Breaking change

• Yes
• No

Additional information

co-authored-by: RickyRicato rickywang44@gmail.com @chichunwang

[zuorenchen]

TODO:

• Docs
• Support rate_limit and time_constant in continuous controller ENH: Discrete and Continuous Controllers #946
• Refactor air_brakes with Actuator class
• Interact with multiple Actuator in a single controller
• Implement in 3-DoF sim

@Gui-FernandesBR @giovaniceotto do you want this in a continuous improvement approach (leave the TODOs in future PRs), or complete all TODOs in one PR?

Feel free to send PRs to branch: /enh/actuator-merge-rocketpy in fork: ARRC-Rocket/ActiveRocketPy/ if you want to contribute more on this topic.