.. _BskSim_scenarios_scenario_AttGuidance:

scenario_AttGuidance
====================

Overview
--------

This script sets up a 6-DOF spacecraft orbiting Earth. The goal of the scenario is to
make use of the hill pointing module with
the :ref:`mrpFeedback` module and a reaction wheel pyramid
to control the attitude all within the new BSK_Sim architecture.

The script is found in the folder ``xmera/examples/BskSim/scenarios`` and executed by using::

      python3 scenario_AttGuidance.py

The simulation mimics the basic simulation simulation in the earlier tutorial in
:ref:`scenarioAttitudeGuidance`.


The simulation layout is shown in the following illustration.

.. image:: /_images/static/test_scenario_AttGuidance.svg
   :align: center

The initial setup for the simulation closely models that of :ref:`scenario_FeedbackRW`.


Custom Dynamics Configurations Instructions
-------------------------------------------

The modules required for this scenario are identical to those used in :ref:`scenario_FeedbackRW`.


Custom FSW Configurations Instructions
--------------------------------------

Three of the four modules required to configure the :ref:`hillPoint` FSW mode have already been included
within the :ref:`BSK_FSW` framework
(``mrpFeedbackRWConfig()``, ``attTrackingErrorConfig()``, ``rwMotorTorqueConfig()``). The only remaining
module is the hill pointing module itself which is set within ``__init__()``.

These modules provide the initial setup for an attitude guidance system that makes use of an hill
pointing model, a module
that tracks the error of the spacecraft's MRP parameters against the vector pointing towards the central, planetary
body, and uses a module that takes that information to provide a torque to correct for the error.

This event is triggered when a user calls `self.masterSim.modeRequest = 'hillPoint'` in any
current or future :ref:`Folder_BskSim` file.

Illustration of Simulation Results
----------------------------------

::

    showPlots = True

.. image:: /_images/Scenarios/scenario_AttGuidance_attitudeErrorNorm.svg
   :align: center

.. image:: /_images/Scenarios/scenario_AttGuidance_rwMotorTorque.svg
   :align: center

.. image:: /_images/Scenarios/scenario_AttGuidance_rateError.svg
   :align: center

.. image:: /_images/Scenarios/scenario_AttGuidance_orientation.svg
   :align: center