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. ------------------------------------------------------------------------- Specification ------------------------------------------------------------------------- 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 ------------------------------------------------------------------------- See also IC623X3, PDDesign, PIDesign, QForm, QLVLH, QMult, QPose, Constant, NPlot, Plot2D, TimeGUI, RK4, JD2000, TOrbit, RVFromKepler, MagField, SunV1 ------------------------------------------------------------------------- % -------------------------------------------------------------------------- Copyright (c) 1999, 2007, 2016, 2021 Princeton Satellite Systems, Inc. All rights reserved. -------------------------------------------------------------------------- Since version 5.5 (2003) 2016.1 Switch to newer IGRF11 model (from 1995 data) for the Earth 2021.2 Removed unused code --------------------------------------------------------------------------
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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