''' '''
'''
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.
'''
import os, inspect
import numpy as np
import math
filename = inspect.getframeinfo(inspect.currentframe()).filename
path = os.path.dirname(os.path.abspath(filename))
# import general simulation support files
from Basilisk.utilities import SimulationBaseClass
from Basilisk.utilities import unitTestSupport # general support file with common unit test functions
from Basilisk.utilities import macros
from Basilisk.utilities import orbitalMotion
# import simulation related support
from Basilisk.simulation import spacecraftPlus
from Basilisk.simulation import exponentialAtmosphere
from Basilisk.utilities import simIncludeGravBody
[docs]def test_unitExponentialAtmosphere():
'''This function is called by the py.test environment.'''
# each test method requires a single assert method to be called
newAtmo = exponentialAtmosphere.ExponentialAtmosphere()
newAtmo.ModelTag = "ExpAtmo"
testResults = []
testMessage = []
addScRes, addScMsg = AddSpacecraftToModel(newAtmo)
testMessage.append(addScMsg)
testResults.append(addScRes)
exponentialRes, exponentialMsg = TestExponentialAtmosphere()
testMessage.append(exponentialMsg)
testResults.append(exponentialRes)
# print out success message if no error were found
snippetName = "passFail"
testSum = sum(testResults)
if testSum == 0:
colorText = 'ForestGreen'
passedText = r'\textcolor{' + colorText + '}{' + "PASSED" + '}'
else:
colorText = 'Red'
passedText = r'\textcolor{' + colorText + '}{' + "Failed" + '}'
unitTestSupport.writeTeXSnippet(snippetName, passedText, path)
assert testSum < 1, testMessage
def AddSpacecraftToModel(atmoModel):
testFailCount = 0
testMessages = []
# create the dynamics task and specify the integration update time
scObject = spacecraftPlus.SpacecraftPlus()
scObject.ModelTag = "spacecraftBody"
scObject.scStateOutMsgName = "inertial_state_output_0"
scObject2 = spacecraftPlus.SpacecraftPlus()
scObject2.ModelTag = "spacecraftBody"
scObject.scStateOutMsgName = "inertial_state_output_1"
# add spacecraftPlus object to the simulation process
atmoModel.addSpacecraftToModel(scObject.scStateOutMsgName)
atmoModel.addSpacecraftToModel(scObject2.scStateOutMsgName)
if len(atmoModel.scStateInMsgNames) != 2:
testFailCount += 1
testMessages.append(
"FAILED: ExponentialAtmosphere does not have enough input message names.")
if len(atmoModel.envOutMsgNames) != 2:
testFailCount += 1
testMessages.append(
"FAILED: ExponentialAtmosphere does not have enough output message names.")
return testFailCount, testMessages
## Test specific atmospheric model performance
def TestExponentialAtmosphere():
testFailCount = 0
testMessages = []
def expAtmoComp(alt, baseDens, scaleHeight):
density = baseDens * math.exp(-alt/scaleHeight)
return density
# 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(10.)
dynProcess.addTask(scSim.CreateNewTask(simTaskName, simulationTimeStep))
# Initialize new atmosphere and drag model, add them to task
newAtmo = exponentialAtmosphere.ExponentialAtmosphere()
newAtmo.ModelTag = "ExpAtmo"
#
# setup the simulation tasks/objects
#
# initialize spacecraftPlus object and set properties
scObject = spacecraftPlus.SpacecraftPlus()
scObject.ModelTag = "spacecraftBody"
# clear prior gravitational body and SPICE setup definitions
gravFactory = simIncludeGravBody.gravBodyFactory()
newAtmo.addSpacecraftToModel(scObject.scStateOutMsgName)
planet = gravFactory.createEarth()
planet.isCentralBody = True # ensure this is the central gravitational body
mu = planet.mu
# attach gravity model to spaceCraftPlus
scObject.gravField.gravBodies = spacecraftPlus.GravBodyVector(list(gravFactory.gravBodies.values()))
#
# setup orbit and simulation time
oe = orbitalMotion.ClassicElements()
r_eq = 6371*1000.0
refBaseDens = 1.217
refScaleHeight = 8500.0
# Set base density, equitorial radius, scale height in Atmosphere
newAtmo.baseDensity = refBaseDens
newAtmo.scaleHeight = refScaleHeight
newAtmo.planetRadius = r_eq
oe.a = r_eq + 300.*1000
oe.e = 0.0
oe.i = 0.0*macros.D2R
oe.Omega = 0.0*macros.D2R
oe.omega = 0.0*macros.D2R
oe.f = 0.0*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
#
# initialize Spacecraft States with 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(0.5*P)
#
# Setup data logging before the simulation is initialized
#
numDataPoints = 10
samplingTime = simulationTime // (numDataPoints-1)
scSim.TotalSim.logThisMessage(scObject.scStateOutMsgName, samplingTime)
scSim.TotalSim.logThisMessage(newAtmo.ModelTag+"_0_data", samplingTime)
# add BSK objects to the simulation process
scSim.AddModelToTask(simTaskName, scObject)
scSim.AddModelToTask(simTaskName, newAtmo)
#
# initialize Simulation
#
scSim.InitializeSimulation()
#
# 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)))
densData = scSim.pullMessageLogData(newAtmo.ModelTag+"_0_data.neutralDensity")
np.set_printoptions(precision=16)
# Compare to expected values
accuracy = 1e-5
unitTestSupport.writeTeXSnippet("toleranceValue", str(accuracy), path)
if len(densData) > 0:
for ind in range(0,len(densData)):
dist = np.linalg.norm(posData[ind, 1:])
alt = dist - newAtmo.planetRadius
trueDensity = expAtmoComp(alt, refBaseDens, refScaleHeight)
# check a vector values
if not unitTestSupport.isDoubleEqualRelative(densData[ind,1], trueDensity,accuracy):
testFailCount += 1
testMessages.append(
"FAILED: ExpAtmo failed density unit test at t=" + str(densData[ind, 0] * macros.NANO2SEC) + "sec with a value difference of "+str(densData[ind,1]-trueDensity))
else:
testFailCount += 1
testMessages.append("FAILED: ExpAtmo failed to pull any logged data")
return testFailCount, testMessages
if __name__=='__main__':
TestExponentialAtmosphere()