Skip to content

Latest commit

 

History

History
65 lines (52 loc) · 2.37 KB

spec_reaction_wheel.md

File metadata and controls

65 lines (52 loc) · 2.37 KB
Raw

Specification for ReactionWheel class

1. Overview

1. functions

  • The ReactionWheel class simulates a reaction wheel.
  • The ReactionWheel class generates torque caused by the reaction wheel.

2. files

  • reaction_wheel.cpp, reaction_wheel.hpp: Definitions and declarations of the class
  • reaction_wheel_ode.cpp, reaction_wheel_ode.hpp: Ordinary differential equation for RW emulation
  • reaction_wheel.ini: Initialization file
  • plot_reaction_wheel.py: An example of a Python script to plot reaction_wheel output

3. how to use

  • Set the parameters in reaction_wheel.ini.
    • moment_of_inertia_kgm2: Moment of inertia of the rotor
    • max_output_torque_Nm: Maximum output torque
    • max_angular_velocity_rpm: Maximum angular velocity
    • Direction parameters
      • direction_determination_mode: Mode of direction definition
      • quaternion_b2c: Quaternion body to component (used in RW jitter)
      • direction_b: Rotation direction
    • position_b_m: Position of the wheel
    • dead_time_s: Dead time
    • time_constant_s: Time constant of the first-order control lag
    • Friction parameters
      • friction_order: Order of friction acceleration
      • friction_coefficients: Coefficients of friction acceleration
    • stop_limit_angular_velocity_rad_s: Stop limit angular velocity
    • initial_motor_drive_flag: Initial motor drive flag
    • initial_angular_velocity_rad_s: Initial angular velocity
    • Other parameters
      • Parameters for the Component class
      • Parameters for the PowerPort class
      • Parameters for the RwJitter class
  • Create an instance by using the initialization function InitReactionWheel
  • Use the SetDriveFlag, SetVelocityLimit_rpm, and SetTargetTorque_* to drive the reaction wheel.
  • Use the GetAngularVelocity_* to get angular velocity information.

2. Explanation of Algorithm

1. MainRoutine

1. Overview

  • The MainRoutine function calculates the generating torque including control lag and friction.

2. Inputs and Outputs

  • TBW

3. Algorithm

  • TBW

3. Results of verifications

  • Case 1
    • Parameters: Default
    • Command: +20 rad/s2 -> -20 rad/s2 -> drive_flag = false.

  • Case 2
    • Parameters: time_constant = 0, friction_coefficients = 1.0
    • Command: +20 rad/s2 -> -20 rad/s2 -> drive_flag = false.