scenarioAttitudeGG

Overview

Illustrates how to add a Module: GravityGradientEffector to a 6U cube-sat spacecraft while a Hill-frame pointing control solution is active. This script expands on scenarioAttitudeGuidance sets up a 6-DOF spacecraft which is orbiting the Earth. More illustrations on using the gravity gradient torque effector can be found in the modules _UnitTest folder.

The script is found in the folder basilisk/examples and executed by using:

python3 scenarioAttitudeGG.py

The simulation layout is shown in the following illustration. The Module: GravityGradientEffector is added to the spacecraft to create a position depended external torque. This

../_images/test_scenarioAttitudeGG.svg

Illustration of Simulation Results

In this simulation the reference frame is not aligned with the Hill frame, but rather it has a fixed angular offset along the 2nd body axis. As the Body frame inertia tensor is diagonal, this reference orientation represents a non-equilibrium gravity gradient torque orientation. Thie simulation results are shown in the following figures:

../_images/scenarioAttitudeGG1.svg../_images/scenarioAttitudeGG2.svg../_images/scenarioAttitudeGG3.svg

Where in scenarioAttitudeGuidance the attitude error asymptotically converged to zero, with the gravity gradient torque the closed loop dynamics is now only Lagrange stable or bounded.

scenarioAttitudeGG.run(show_plots)[source]

The scenarios can be run with the followings setups parameters:

Parameters:

show_plots (bool) – Determines if the script should display plots