''' '''
'''
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 Unit Test
#
# Purpose: Unit test of the dynamics integrator function
# Author: Hanspeter Schaub
# Creation Date: Dec. 14, 2016
#
import pytest
import os
import inspect
import numpy as np
# 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
from Basilisk.utilities import orbitalMotion
# import simulation related support
from Basilisk.simulation import spacecraftPlus
from Basilisk.utilities import simIncludeGravBody
from Basilisk.simulation import svIntegrators
# @cond DOXYGEN_IGNORE
filename = inspect.getframeinfo(inspect.currentframe()).filename
path = os.path.dirname(os.path.abspath(filename))
# @endcond
# 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(True, reason="Scott's brain no-worky\n")
# The following 'parametrize' function decorator provides the parameters and expected results for each
# of the multiple test runs for this test.
[docs]@pytest.mark.parametrize("integratorCase", ["rk4", "euler", "rk2"])
def test_scenarioIntegrators(show_plots, integratorCase):
'''This function is called by the py.test environment.'''
# each test method requires a single assert method to be called
[testResults, testMessage] = run( True,
show_plots, integratorCase)
assert testResults < 1, testMessage
[docs]def run(doUnitTests, show_plots, integratorCase):
'''Call this routine directly to run the tutorial scenario.'''
testFailCount = 0 # zero unit test result counter
testMessages = [] # create empty array to store test log messages
# Create simulation variable names
simTaskName = "simTask"
simProcessName = "simProcess"
# Create a sim module as an empty container
scSim = SimulationBaseClass.SimBaseClass()
#
# create the simulation process
#
dynProcess = scSim.CreateNewProcess(simProcessName)
# create the dynamics task and specify the integration update time
simulationTimeStep = macros.sec2nano(120.)
dynProcess.addTask(scSim.CreateNewTask(simTaskName, simulationTimeStep))
# if this scenario is to interface with the BSK Viz, uncomment the following lines
# unitTestSupport.enableVisualization(scSim, dynProcess, simProcessName, 'earth') # The Viz only support 'earth', 'mars', or 'sun'
#
# setup the simulation tasks/objects
#
# initialize spacecraftPlus object and set properties
scObject = spacecraftPlus.SpacecraftPlus()
scObject.ModelTag = "spacecraftBody"
# default case, RK4 is automatically setup, no extra code is needed
if integratorCase == "euler":
integratorObject = svIntegrators.svIntegratorEuler(scObject)
scObject.setIntegrator(integratorObject)
elif integratorCase == "rk2":
integratorObject = svIntegrators.svIntegratorRK2(scObject)
scObject.setIntegrator(integratorObject)
# add spacecraftPlus object to the simulation process
scSim.AddModelToTask(simTaskName, scObject)
# clear prior gravitational body and SPICE setup definitions
gravFactory = simIncludeGravBody.gravBodyFactory()
earth = gravFactory.createEarth()
earth.isCentralBody = True # ensure this is the central gravitational body
mu = earth.mu
# attach gravity model to spaceCraftPlus
scObject.gravField.gravBodies = spacecraftPlus.GravBodyVector(list(gravFactory.gravBodies.values()))
#
# setup orbit and simulation time
#
# setup the orbit using classical orbit elements
oe = orbitalMotion.ClassicElements()
rLEO = 7000.*1000 # meters
oe.a = rLEO
oe.e = 0.0001
oe.i = 33.3*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)
#
# initialize Spacecraft States with in the initialization variables
#
scObject.hub.r_CN_NInit = unitTestSupport.np2EigenVectorXd(rN) # m - r_CN_N
scObject.hub.v_CN_NInit = unitTestSupport.np2EigenVectorXd(vN) # m - v_CN_N
# set the simulation time
n = np.sqrt(mu/oe.a/oe.a/oe.a)
P = 2.*np.pi/n
simulationTime = macros.sec2nano(0.75*P)
#
# Setup data logging before the simulation is initialized
#
numDataPoints = 100
samplingTime = simulationTime // numDataPoints
scSim.TotalSim.logThisMessage(scObject.scStateOutMsgName, samplingTime)
#
# initialize Simulation
#
scSim.InitializeSimulationAndDiscover()
#
# configure a simulation stop time time and execute the simulation run
#
scSim.ConfigureStopTime(simulationTime)
scSim.ExecuteSimulation()
#
# retrieve the logged data
#
posData = scSim.pullMessageLogData(scObject.scStateOutMsgName+'.r_BN_N', list(range(3)))
velData = scSim.pullMessageLogData(scObject.scStateOutMsgName+'.v_BN_N', list(range(3)))
#
# plot the results
#
np.set_printoptions(precision=16)
fileNameString = filename[len(path)+6:-3]
if integratorCase == "rk4":
plt.close("all") # clears out plots from earlier test runs
# draw orbit in perifocal frame
b = oe.a*np.sqrt(1-oe.e*oe.e)
p = oe.a*(1-oe.e*oe.e)
plt.figure(1,figsize=np.array((1.0, b/oe.a))*4.75,dpi=100)
plt.axis(np.array([-oe.rApoap, oe.rPeriap, -b, b])/1000*1.25)
# draw the planet
fig = plt.gcf()
fig.set_tight_layout(False)
ax = fig.gca()
planetColor= '#008800'
planetRadius = earth.radEquator/1000
ax.add_artist(plt.Circle((0, 0), planetRadius, color=planetColor))
# draw the actual orbit
rData = []
fData = []
labelStrings = ("rk4", "euler", "rk2")
for idx in range(0, len(posData)):
oeData = orbitalMotion.rv2elem(mu, posData[idx, 1:4], velData[idx, 1:4])
rData.append(oeData.rmag)
fData.append(oeData.f + oeData.omega - oe.omega)
plt.plot(rData*np.cos(fData)/1000, rData*np.sin(fData)/1000
, color=unitTestSupport.getLineColor(labelStrings.index(integratorCase)+1, 3)
, label=integratorCase
, linewidth=3.0
)
# draw the full osculating orbit from the initial conditions
fData = np.linspace(0, 2*np.pi, 100)
rData = []
for idx in range(0, len(fData)):
rData.append(p/(1+oe.e*np.cos(fData[idx])))
plt.plot(rData*np.cos(fData)/1000, rData*np.sin(fData)/1000
, '--'
, color='#555555'
)
plt.xlabel('$i_e$ Cord. [km]')
plt.ylabel('$i_p$ Cord. [km]')
plt.legend(loc='lower right')
plt.grid()
if doUnitTests: # only save off the figure if doing a unit test run
# unitTestSupport.saveScenarioFigure(
# fileNameString
# , plt, path)
# unitTestSupport.saveFigurePDF(
# fileNameString
# , plt, path
# )
unitTestSupport.writeFigureLaTeX(
"scenarioIntegrators",
"Illustration of the BSK integrated trajectories",
plt,
"",
path)
if show_plots:
plt.show()
plt.close('all')
# # close the plots being saved off to avoid over-writing old and new figures
# plt.close("all")
#
# the python code below is for the unit testing mode. If you are studying the scenario
# to learn how to run BSK, you can stop reading below this line.
#
if doUnitTests:
numTruthPoints = 5
skipValue = int(len(posData)/(numTruthPoints-1))
dataPosRed = posData[::skipValue]
# setup truth data for unit test
if integratorCase is "rk4":
truePos = [
[-2.8168016010234915e6, 5.248174846916147e6, 3.677157264677297e6]
, [-6.379381726549218e6, -1.4688565370540658e6, 2.4807857675497606e6]
, [-2.230094305694789e6, -6.410420020364709e6, -1.7146277675541767e6]
, [4.614900659014343e6, -3.60224207689023e6, -3.837022825958977e6]
, [5.879095186201691e6, 3.561495655367985e6, -1.3195821703218794e6]
]
if integratorCase is "euler":
truePos = [
[-2.8168016010234915e6, 5.248174846916147e6, 3.677157264677297e6]
, [-7.061548530211288e6, -1.4488790844105487e6, 2.823580168201031e6]
, [-4.831279689590867e6, -8.015202650472983e6, -1.1434851461593418e6]
, [719606.5825106134, -1.0537603309084207e7, -4.966060248346598e6]
, [6.431097055190775e6, -9.795566286964862e6, -7.438012269629238e6]
]
if integratorCase is "rk2":
truePos = [
[-2.8168016010234915e6, 5.248174846916147e6, 3.677157264677297e6]
, [-6.425636528569288e6, -1.466693214251768e6, 2.50438327358707e6]
, [-2.466642497083674e6, -6.509473992136429e6, -1.6421621818735446e6]
, [4.342561337924192e6, -4.1593822658140697e6, -3.947594705237753e6]
, [6.279757158711852e6, 2.8527385905952943e6, -1.8260959147806289e6]
]
# compare the results to the truth values
accuracy = 1.0 # meters
testFailCount, testMessages = unitTestSupport.compareArray(
truePos, dataPosRed, accuracy, "r_BN_N Vector",
testFailCount, testMessages)
# print out success message if no error were found
if testFailCount == 0:
print("PASSED ")
passFailText = "PASSED"
colorText = 'ForestGreen' # color to write auto-documented "PASSED" message in in LATEX
snippetContent = ""
else:
print(testFailCount)
print(testMessages)
passFailText = 'FAILED'
colorText = 'Red' # color to write auto-documented "FAILED" message in in LATEX
snippetContent = r"\begin{verbatim}"
for message in testMessages:
snippetContent += message
snippetContent += r"\end{verbatim}"
snippetMsgName = fileNameString + 'Msg-' + integratorCase
unitTestSupport.writeTeXSnippet(snippetMsgName, snippetContent,
path)
snippetPassFailName = fileNameString + 'TestMsg-' + integratorCase
snippetContent = r'\textcolor{' + colorText + '}{' + passFailText + '}'
unitTestSupport.writeTeXSnippet(snippetPassFailName, snippetContent,
path)
# each test method requires a single assert method to be called
# this check below just makes sure no sub-test failures were found
return [testFailCount, ''.join(testMessages)]
#
# This statement below ensures that the unit test scrip can be run as a
# stand-along python script
#
if __name__ == "__main__":
run(True, # do unit tests
True, # show_plots
'rk4') # integrator case(0 - RK4, 1 - Euler, 2 - RK2)