Simulate a 3-axis stabilized control system

Modified on Thu, 7 Sep, 2023 at 3:46 PM

The Attitude3D demo Implements a 3-axis control system for a rigid spacecraft using a CAD model and the full disturbance model, which includes drag, solar and planetary radiation perturbations, and optionally magnetic and thermal torques. This demo loads the XYZSat CAD model from a mat-file, as shown in this snippet:

g = load('XYZSat');
ShowCAD( g );

The figure produced by ShowCAD is shown below.

The controller is implemented in state space form as:

  % Controller blocks, delta format. Each axis uses the same gains.
  %----------------------------------------------------------------
  accel    = zeros(3,1);
  accel(1) =          c*xRoll  + d*angleError(1);
  xRoll    = xRoll  + a*xRoll  + b*angleError(1);

  accel(2) =          c*xPitch + d*angleError(2);
  xPitch   = xPitch + a*xPitch + b*angleError(2);

  accel(3) =         c*xYaw   + d*angleError(3);
  xYaw     = xYaw  + a*xYaw   + b*angleError(3);

  torque = -g.mass.inertia*accel;

The full disturbance model is called by passing in the data structure of the CAD Model as:

% Use disturbances model (uses CAD model)
e.r         = x2(1:3);
e.v         = x2(4:6);
[f,t]       = Disturbances('run',g,e,hD);
fDist = f.total/1000; % to kN from N
tDist = t.total;      % already in Nm

Module: SC/Demos/Attitude

Children: PIDMIMO, Disturbances, DrawSCPlugIn

Published demo: Attitude3D.m