# ISC License
#
# Copyright (c) 2016, Autonomous Vehicle Systems Lab, University of Colorado at Boulder
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
# Basilisk Integrated Test of the Solar Radiation Pressure Evaluation
#
# Purpose: Integrated test of the spacecraft(), gravity modules and the solar
# radiation pressure modeling. Currently the cannonball model is only tested.
# Author: Patrick Kenneally
# Creation Date: June 11, 2018
#
import os
import matplotlib.pyplot as plt
import numpy as np
from Basilisk import __path__
bskPath = __path__[0]
from Basilisk.simulation import spacecraft, radiationPressure
from Basilisk.utilities import (SimulationBaseClass, macros, orbitalMotion,
unitTestSupport)
from Basilisk.utilities.simIncludeGravBody import gravBodyFactory
# uncomment this line is this test is to be skipped in the global unit test run, adjust message as needed
# @pytest.mark.skipif(conditionstring)
# uncomment this line if this test has an expected failure, adjust message as needed
# @pytest.mark.xfail() # need to update how the RW states are defined
# provide a unique test method name, starting with test_
[docs]def test_radiationPressureIntegratedTest(show_plots):
"""Module Unit Test"""
[testResults, testMessage] = radiationPressureIntegratedTest(show_plots)
assert testResults < 1, testMessage
def radiationPressureIntegratedTest(show_plots):
# Create simulation variable names
simTaskName = "simTask"
simProcessName = "simProcess"
# Create a sim module as an empty container
sim = SimulationBaseClass.SimBaseClass()
dynProcess = sim.CreateNewProcess(simProcessName)
# create the dynamics task and specify the integration update time
simulationTimeStep = macros.sec2nano(10.0)
dynProcess.addTask(sim.CreateNewTask(simTaskName, simulationTimeStep))
# initialize spacecraft object and set properties
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
sim.AddModelToTask(simTaskName, scObject)
srp = radiationPressure.RadiationPressure() # default model is the SRP_CANNONBALL_MODEL
srp.area = 1.0
srp.coefficientReflection = 1.3
sim.AddModelToTask(simTaskName, srp, -1)
scObject.addDynamicEffector(srp)
# setup Gravity Body
gravFactory = gravBodyFactory()
planet = gravFactory.createEarth()
planet.isCentralBody = True
mu = planet.mu
gravFactory.createSun()
spice_path = bskPath + '/supportData/EphemerisData/'
gravFactory.createSpiceInterface(spice_path, '2021 MAY 04 07:47:49.965 (UTC)')
gravFactory.spiceObject.zeroBase = 'Earth'
sim.AddModelToTask(simTaskName, gravFactory.spiceObject, -1)
srp.sunEphmInMsg.subscribeTo(gravFactory.spiceObject.planetStateOutMsgs[1])
# attach gravity model to spacecraft
scObject.gravField.gravBodies = spacecraft.GravBodyVector(list(gravFactory.gravBodies.values()))
# setup the orbit using classical orbit elements
oe = orbitalMotion.ClassicElements()
rGEO = 42000. * 1000 # meters
oe.a = rGEO
oe.e = 0.00001
oe.i = 0.0 * macros.D2R
oe.Omega = 48.2 * macros.D2R
oe.omega = 347.8 * macros.D2R
oe.f = 85.3 * macros.D2R
rN, vN = orbitalMotion.elem2rv(mu, oe)
oe = orbitalMotion.rv2elem(mu, rN, vN) # this stores consistent initial orbit elements
# with circular or equatorial orbit, some angles are arbitrary
print(rN)
#
# initialize Spacecraft States with the initialization variables
#
scObject.hub.r_CN_NInit = rN # m - r_BN_N
scObject.hub.v_CN_NInit = vN # m/s - v_BN_N
# set the simulation time
n = np.sqrt(mu / oe.a / oe.a / oe.a)
P = 2. * np.pi / n
simulationTime = macros.sec2nano(P)
# Setup data logging before the simulation is initialized
numDataPoints = 100
samplingTime = simulationTime // (numDataPoints - 1)
dataLog = scObject.scStateOutMsg.recorder()
earthLog = gravFactory.spiceObject.planetStateOutMsgs[0].recorder()
logTaskName = "logTask"
dynProcess.addTask(sim.CreateNewTask(logTaskName, samplingTime))
sim.AddModelToTask(logTaskName, dataLog)
sim.AddModelToTask(logTaskName, earthLog)
#
# initialize Simulation: This function clears the simulation log, and runs the self_init()
# cross_init() and reset() routines on each module.
# If the routine InitializeSimulationAndDiscover() is run instead of InitializeSimulation(),
# then the all messages are auto-discovered that are shared across different BSK threads.
#
sim.InitializeSimulation()
#
# configure a simulation stop time and execute the simulation run
#
sim.ConfigureStopTime(simulationTime)
sim.ExecuteSimulation()
# unload spice kernels
gravFactory.unloadSpiceKernels()
#
# retrieve the logged data
#
earthEphm = earthLog.PositionVector
posData = dataLog.r_BN_N
pos_rel_earth = posData[:, 0:3] - earthEphm[:, 0:3]
testFailCount = 0 # zero unit test result counter
testMessages = [] # create empty array to store test log messages
numTruthPoints = 10
skipValue = int(len(pos_rel_earth) / (numTruthPoints - 1))
pos_rel_earth_parse = pos_rel_earth[::skipValue]
# true position for un perturbed 2 body GEO orbit with cannonball SRP
true_pos = np.array([[-2.18197848e+07, 3.58872415e+07, 0.00000000e+00]
,[-3.97753187e+07, 1.34888792e+07, -7.33231880e+01]
,[-3.91389859e+07, -1.52401375e+07, -3.06322198e+02]
,[-2.01838008e+07, -3.68366952e+07, -6.37764168e+02]
,[ 8.21683806e+06, -4.11950440e+07, -9.13393204e+02]
,[ 3.27532709e+07, -2.63024006e+07, -9.57828703e+02]
,[ 4.19944648e+07, 9.02522873e+05, -6.78102461e+02]
,[ 3.15828214e+07, 2.76842358e+07, -1.40473487e+02]
,[ 6.38617052e+06, 4.15047581e+07, 4.29674085e+02]
,[-2.18006914e+07, 3.58874726e+07, 7.40872311e+02]])
# compare the results to the truth values
accuracy = 1.0 # meters
testFailCount, testMessages = unitTestSupport.compareArray(
true_pos, pos_rel_earth_parse, accuracy, "r_BN_N Vector",
testFailCount, testMessages)
# print out success message if no error were found
if testFailCount == 0:
print("PASSED ")
else:
print(testFailCount)
print(testMessages)
plt.close("all") # clears out plots from earlier test runs
plt.figure(1)
fig = plt.gcf()
ax = fig.gca()
ax.ticklabel_format(useOffset=False, style='plain')
for idx in range(0, 3):
plt.plot(dataLog.times() * macros.NANO2SEC / P, pos_rel_earth[:, idx] / 1000.,
color=unitTestSupport.getLineColor(idx, 3),
label='$r_{BN,' + str(idx) + '}$')
plt.legend(loc='lower right')
plt.xlabel('Time [orbits]')
plt.ylabel('Inertial Position [km]')
plt.title('Position Relative To Earth')
if show_plots:
plt.show()
plt.close('all')
figureList = {}
fileName = os.path.basename(os.path.splitext(__file__)[0])
pltName = fileName + "srp_integrated"
figureList[pltName] = plt.figure(1)
return testFailCount, testMessages
#
# This statement below ensures that the unit test script can be run as a stand-alone python script
#
if __name__ == "__main__":
radiationPressureIntegratedTest(True)