.. _thrFiringRound:

:module-type:`Python` Module: thrFiringRound
============================================

Executive Summary
-----------------

This module converts thruster force commands into thruster on-time commands.
Each positive force command is normalized by the configured maximum thrust,
scaled by the control period, clipped to the control period, rounded to the
nearest configured on-time resolution, and checked to make sure it is longer
than the minimum fire time.


Message Connection Descriptions
-------------------------------
The following diagram and table list the module input and output messages.

.. bsk-module-io:: ThrFiringRound
    :caption: Module I/O Messages

    input thrForceInMsg THRArrayCmdForceMsgPayload
        Input thruster force command message.

    output thrOnTimeOutMsg THRArrayOnTimeCmdMsgPayload
        Output thruster on-time command message.


Module Assumptions and Limitations
----------------------------------
Negative force commands are treated as zero-force requests because the on-time
logic is one-sided.  The number of thrusters can be set directly with
``setNumThrusters``.  If it is not set, the module uses the length of the
configured maximum-thrust vector, or the length of the input force command when
the maximum thrust is scalar.


User Guide
----------
The module is imported through the standard flight-software package:

.. code-block:: python

    from Basilisk.fswAlgorithms import thrFiringRound

    rounder = thrFiringRound.ThrFiringRound()
    rounder.ModelTag = "thrFiringRound"

The control period, on-time resolution, minimum thruster on-time,
number of thrusters, and maximum thruster force are configured
with setter methods:

.. code-block:: python

    rounder.setControlPeriodSec(10.0)
    rounder.setOnTimeResolutionSec(0.1)
    rounder.setThrMinFireTime(0.15)
    rounder.setNumThrusters(2)
    rounder.setThrForceMax([2.5, 2.5])


----

.. toctree::
   :maxdepth: 1
   :caption: Files:

.. automodule:: thrFiringRound
   :members:
   :show-inheritance: