MagSim:

Path: SC/MagneticControl

% Simulate a momentum bias spacecraft with magnetic roll/yaw control.
 The orbit is modeled and the spacecraft controls errors with respect to 
 the LVLH frame.
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   Specification
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 The controller uses the momentum wheel to control pitch and magnetic torquer
 control for roll and yaw. The 3-axis controller is a 3-axis PD and 
 torque demand is handed to the torquers. We assume that the torquers
 allow linear actuation. For the purposes of the simulation we compute
 the dipole required to meet the instantaneous torque demand. We ignore the
 disturbance the torquers create around pitch and also the momentum unloading
 system. This script is useful for sizing the control system.

 The inertia in the three directions are Ix=120, Iy=120 and Iz=1.3. The
 satellite is in an equatorial orbit so that the field is almost normal to the orbit.
 
 The damping ratios and natural frequencies are:
 
   Tach loop:
   zeta = 0.7621
   wN= 0.5
 
   Pitch and Roll loop:
   zeta = 0.7621
   wN   = 0.009
 
   Yaw loop:
   zeta = 1.0
   wN   = 0.15
 
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  See also IC623X3, PDDesign, PIDesign, QForm, QLVLH, QMult, QPose, 
  Constant, NPlot, Plot2D, TimeGUI, RK4, JD2000, TOrbit, RVFromKepler, 
  MagField, SunV1
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%
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   Copyright (c) 1999, 2007, 2016, 2021 Princeton Satellite Systems, Inc.
   All rights reserved.
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   Since version 5.5 (2003)
   2016.1 Switch to newer IGRF11 model (from 1995 data) for the Earth
   2021.2 Removed unused code
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Children:

AerospaceUtils: Coord/QLVLH
SC: BasicOrbit/RVFromKepler
SC: Environs/MagField
SC: Ephem/SunV1
SC: SCMat/IGRF11
Common: Control/PDDesign
Common: Control/PIDesign
Common: Database/Constant
Common: GUIs/TimeGUI
Common: Graphics/Plot2D
Common: MassProperties/IC623X3
Common: Quaternion/QForm
Common: Quaternion/QMult
Common: Quaternion/QPose
Common: Time/JD2000
Math: Integration/RK4

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