Source code for scenarioSpiceSpacecraft

#
#  ISC License
#
#  Copyright (c) 2021, Autonomous Vehicle Systems Lab, University of Colorado at Boulder
#
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r"""

.. raw:: html

    <iframe width="560" height="315" src="https://www.youtube.com/embed/Fux_UsZ5FR0" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Overview
--------

Demonstrates how to use :ref:`spiceInterface` to load a Spice kernel with the Hubble orbital
information and use the corresponding :ref:`transRefMsgPayload` output message
to specify the spacecraft motion.  With this approach the spacecraft attitude is still
dynamic and can achieve the same inertial pointing goal as setup in
:ref:`scenarioAttitudeFeedback`.

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

      python3 scenarioSpiceSpacecraft.py

The simulation layout is
shown in the following illustration.  Note that here the ``spiceInterface`` module
must be executed prior to :ref:`spacecraft` as the
:ref:`transRefMsgPayload` input message must be properly setup before initializing
the spacecraft module which reads this in during ``Reset()``.

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


When the simulation completes 2 plots are shown for the MRP attitude tracking error history,
as well as the Hubble inertial orbital coordinates with respect to the Earth.

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

::

    show_plots = True

.. image:: /_images/Scenarios/scenarioSpiceSpacecraft1.svg
   :align: center

.. image:: /_images/Scenarios/scenarioSpiceSpacecraft2.svg
   :align: center



"""

#
# Basilisk Scenario Script and Integrated Test
#
# Purpose:  Integrated test of the spacecraft(), extForceTorque, simpleNav() and
#           mrpFeedback() modules.  Illustrates a 6-DOV spacecraft detumbling in orbit
# Author:   Hanspeter Schaub
# Creation Date:  Nov. 19, 2016
#
import os

import numpy as np

np.set_printoptions(precision=16)

# import general simulation support files
from Basilisk.utilities import SimulationBaseClass
from Basilisk.utilities import unitTestSupport  # general support file with common unit test functions
import matplotlib.pyplot as plt
from Basilisk.utilities import macros

# import simulation related support
from Basilisk.simulation import spacecraft
from Basilisk.simulation import extForceTorque
from Basilisk.utilities import simIncludeGravBody
from Basilisk.simulation import simpleNav

# import FSW Algorithm related support
from Basilisk.fswAlgorithms import mrpFeedback
from Basilisk.fswAlgorithms import inertial3D
from Basilisk.fswAlgorithms import attTrackingError

# import message declarations
from Basilisk.architecture import messaging

# attempt to import vizard
from Basilisk.utilities import vizSupport


# The path to the location of Basilisk
# Used to get the location of supporting data.
from Basilisk import __path__
bskPath = __path__[0]
fileName = os.path.basename(os.path.splitext(__file__)[0])


[docs] def run(show_plots): """ The scenarios can be run with the followings setups parameters: Args: show_plots (bool): Determines if the script should display plots """ # Create simulation variable names simTaskName = "simTask" simProcessName = "simProcess" # Create a sim module as an empty container scSim = SimulationBaseClass.SimBaseClass() # set the simulation time variable used later on simulationTime = macros.min2nano(10.) # # create the simulation process # dynProcess = scSim.CreateNewProcess(simProcessName) # create the dynamics task and specify the integration update time simulationTimeStep = macros.sec2nano(.1) dynProcess.addTask(scSim.CreateNewTask(simTaskName, simulationTimeStep)) # # setup the simulation tasks/objects # # initialize spacecraft object and set properties scObject = spacecraft.Spacecraft() scObject.ModelTag = "Hubble" # define the simulation inertia I = [900., 0., 0., 0., 800., 0., 0., 0., 600.] scObject.hub.mHub = 750.0 # kg - spacecraft mass scObject.hub.IHubPntBc_B = unitTestSupport.np2EigenMatrix3d(I) # add spacecraft object to the simulation process # clear prior gravitational body and SPICE setup definitions gravFactory = simIncludeGravBody.gravBodyFactory() # setup Earth Gravity Body earth = gravFactory.createEarth() earth.isCentralBody = True # ensure this is the central gravitational body mu = earth.mu # attach gravity model to spacecraft gravFactory.addBodiesTo(scObject) # setup spice library for Earth ephemeris and Hubble states timeInitString = "2015 February 10, 00:00:00.0 TDB" spiceObject = gravFactory.createSpiceInterface(time=timeInitString, epochInMsg=True) spiceObject.zeroBase = 'Earth' scNames = ["HUBBLE SPACE TELESCOPE"] spiceObject.addSpacecraftNames(messaging.StringVector(scNames)) spiceObject.loadSpiceKernel("hst_edited.bsp", bskPath + '/supportData/EphemerisData/') # need spice to run before spacecraft module as it provides the spacecraft translational states scSim.AddModelToTask(simTaskName, spiceObject) scSim.AddModelToTask(simTaskName, scObject) # setup extForceTorque module # the control torque is read in through the messaging system extFTObject = extForceTorque.ExtForceTorque() extFTObject.ModelTag = "externalDisturbance" scObject.addDynamicEffector(extFTObject) scSim.AddModelToTask(simTaskName, extFTObject) # add the simple Navigation sensor module. This sets the SC attitude, rate, position # velocity navigation message sNavObject = simpleNav.SimpleNav() sNavObject.ModelTag = "SimpleNavigation" scSim.AddModelToTask(simTaskName, sNavObject) # # setup the FSW algorithm tasks # # setup inertial3D guidance module inertial3DObj = inertial3D.inertial3D() inertial3DObj.ModelTag = "inertial3D" scSim.AddModelToTask(simTaskName, inertial3DObj) inertial3DObj.sigma_R0N = [0., 0., 0.] # set the desired inertial orientation # setup the attitude tracking error evaluation module attError = attTrackingError.attTrackingError() attError.ModelTag = "attErrorInertial3D" scSim.AddModelToTask(simTaskName, attError) # setup the MRP Feedback control module mrpControl = mrpFeedback.mrpFeedback() mrpControl.ModelTag = "mrpFeedback" scSim.AddModelToTask(simTaskName, mrpControl) mrpControl.K = 3.5 mrpControl.Ki = -1 # make value negative to turn off integral feedback mrpControl.P = 30.0 mrpControl.integralLimit = 2. / mrpControl.Ki * 0.1 # # create simulation messages # # The MRP Feedback algorithm requires the vehicle configuration structure. This defines various spacecraft # related states such as the inertia tensor and the position vector between the primary Body-fixed frame # B origin and the center of mass (defaulted to zero). The message payload is created through configData = messaging.VehicleConfigMsgPayload() configData.ISCPntB_B = I configDataMsg = messaging.VehicleConfigMsg().write(configData) # # connect the messages to the modules # sNavObject.scStateInMsg.subscribeTo(scObject.scStateOutMsg) attError.attNavInMsg.subscribeTo(sNavObject.attOutMsg) attError.attRefInMsg.subscribeTo(inertial3DObj.attRefOutMsg) mrpControl.guidInMsg.subscribeTo(attError.attGuidOutMsg) mrpControl.vehConfigInMsg.subscribeTo(configDataMsg) extFTObject.cmdTorqueInMsg.subscribeTo(mrpControl.cmdTorqueOutMsg) scObject.transRefInMsg.subscribeTo(spiceObject.transRefStateOutMsgs[0]) # # Setup data logging before the simulation is initialized # numDataPoints = 100 samplingTime = unitTestSupport.samplingTime(simulationTime, simulationTimeStep, numDataPoints) snLog = sNavObject.scStateInMsg.recorder(samplingTime) attErrorLog = attError.attGuidOutMsg.recorder(samplingTime) mrpLog = mrpControl.cmdTorqueOutMsg.recorder(samplingTime) scSim.AddModelToTask(simTaskName, snLog) scSim.AddModelToTask(simTaskName, attErrorLog) scSim.AddModelToTask(simTaskName, mrpLog) # # set initial Spacecraft States # scObject.hub.sigma_BNInit = [[0.1], [0.2], [-0.3]] # sigma_BN_B scObject.hub.omega_BN_BInit = [[0.001], [-0.01], [0.03]] # rad/s - omega_BN_B # if this scenario is to interface with the BSK Viz, uncomment the following line vizSupport.enableUnityVisualization(scSim, simTaskName, scObject # , saveFile=fileName ) # # initialize Simulation # scSim.InitializeSimulation() # # configure a simulation stop time and execute the simulation run # scSim.ConfigureStopTime(simulationTime) scSim.ExecuteSimulation() # unload custom Spice kernel gravFactory.unloadSpiceKernels() spiceObject.unloadSpiceKernel("hst_edited.bsp", bskPath + '/supportData/EphemerisData/') # # plot the results # timeAxis = attErrorLog.times() plt.close("all") # clears out plots from earlier test runs plt.figure(1) for idx in range(3): plt.plot(timeAxis * macros.NANO2MIN, attErrorLog.sigma_BR[:, idx], color=unitTestSupport.getLineColor(idx, 3), label=r'$\sigma_' + str(idx) + '$') plt.legend(loc='lower right') plt.xlabel('Time [min]') plt.ylabel(r'Attitude Error $\sigma_{B/R}$') figureList = {} pltName = fileName + "1" figureList[pltName] = plt.figure(1) plt.figure(2) for idx in range(3): plt.plot(timeAxis * macros.NANO2MIN, mrpLog.torqueRequestBody[:, idx], color=unitTestSupport.getLineColor(idx, 3), label='$L_{r,' + str(idx) + '}$') plt.legend(loc='lower right') plt.xlabel('Time [min]') plt.ylabel(r'Control Torque $L_r$ [Nm]') pltName = fileName + "2" plt.figure(3) for idx in range(3): plt.plot(timeAxis * macros.NANO2MIN, attErrorLog.omega_BR_B[:, idx], color=unitTestSupport.getLineColor(idx, 3), label=r'$\omega_{BR,' + str(idx) + '}$') plt.legend(loc='lower right') plt.xlabel('Time [min]') plt.ylabel('Rate Tracking Error [rad/s] ') plt.figure(4) for idx in range(3): plt.plot(timeAxis * macros.NANO2MIN, snLog.r_BN_N[:, idx] / 1000., color=unitTestSupport.getLineColor(idx, 3), label='$r_{BN,' + str(idx) + '}$') plt.legend(loc='lower right') plt.xlabel('Time [min]') plt.ylabel('Inertial Position [km]') figureList[pltName] = plt.figure(4) if show_plots: plt.show() # close the plots being saved off to avoid over-writing old and new figures plt.close("all") return figureList
# # This statement below ensures that the unit test scrip can be run as a # stand-along python script # if __name__ == "__main__": run( True # show_plots )