# ISC License
#
# Copyright (c) 2016-2018, 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.
#
#
#
# Purpose: Test the facetDrag module.
# Author: Andrew Harris
# Creation Date: May 16 2019
#
import os, inspect
import numpy as np
filename = inspect.getframeinfo(inspect.currentframe()).filename
path = os.path.dirname(os.path.abspath(filename))
bskName = 'Basilisk'
splitPath = path.split(bskName)
# import general simulation support files
from Basilisk.utilities import SimulationBaseClass
from Basilisk.utilities import macros
from Basilisk.utilities import orbitalMotion
from Basilisk.utilities import RigidBodyKinematics as rbk
# import simulation related support
from Basilisk.simulation import spacecraft
from Basilisk.simulation import exponentialAtmosphere
from Basilisk.simulation import facetDragDynamicEffector
from Basilisk.simulation import simpleNav
from Basilisk.utilities import unitTestSupport
from Basilisk.utilities import simIncludeGravBody
from Basilisk.architecture import messaging
#print dir(exponentialAtmosphere)
[docs]def test_unitFacetDrag():
"""This function is called by the py.test environment."""
# each test method requires a single assert method to be called
testResults = []
testMessage = []
dragRes, dragMsg = TestDragCalculation()
testMessage.append(dragMsg)
testResults.append(dragRes)
shadowRes, shadowMsg = TestShadowCalculation()
testMessage.append(shadowMsg)
testResults.append(shadowRes)
testSum = sum(testResults)
snippetName = "unitTestPassFail"
if testSum == 0:
colorText = 'ForestGreen'
print("PASSED")
passedText = r'\textcolor{' + colorText + '}{' + "PASSED" + '}'
else:
colorText = 'Red'
print("Failed")
passedText = r'\textcolor{' + colorText + '}{' + "Failed" + '}'
unitTestSupport.writeTeXSnippet(snippetName, passedText, path)
assert testSum < 1, testMessage
def TestDragCalculation():
# Init test support variables
testFailCount = 0
testMessages = []
## Simulation initialization
simTaskName = "simTask"
simProcessName = "simProcess"
scSim = SimulationBaseClass.SimBaseClass()
dynProcess = scSim.CreateNewProcess(simProcessName)
simulationTimeStep = macros.sec2nano(5.)
dynProcess.addTask(scSim.CreateNewTask(simTaskName, simulationTimeStep))
# initialize spacecraft object and set properties
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
## Initialize new atmosphere and drag model, add them to task
newAtmo = exponentialAtmosphere.ExponentialAtmosphere()
newAtmo.ModelTag = "ExpAtmo"
newAtmo.addSpacecraftToModel(scObject.scStateOutMsg)
newDrag = facetDragDynamicEffector.FacetDragDynamicEffector()
newDrag.ModelTag = "FacetDrag"
newDrag.atmoDensInMsg.subscribeTo(newAtmo.envOutMsgs[0])
scObject.addDynamicEffector(newDrag)
try:
scAreas = [1.0, 1.0]
scCoeff = np.array([2.0, 2.0])
B_normals = [np.array([1, 0, 0]), np.array([0, 1, 0])]
B_locations = [np.array([0.1,0,0]), np.array([0,0.1,0])]
for i in range(0,len(scAreas)):
newDrag.addFacet(scAreas[i], scCoeff[i], B_normals[i], B_locations[i])
except:
testFailCount += 1
testMessages.append("ERROR: FacetDrag unit test failed while setting facet parameters.")
return testFailCount, testMessages
# clear prior gravitational body and SPICE setup definitions
gravFactory = simIncludeGravBody.gravBodyFactory()
planet = gravFactory.createEarth()
planet.isCentralBody = True # ensure this is the central gravitational body
mu = planet.mu
# attach gravity model to spacecraft
scObject.gravField.gravBodies = spacecraft.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
rN = np.array([r_eq+200.0e3,0,0])
vN = np.array([0,7.788e3,0])
sig_BN = np.array([0,0,0])
# initialize Spacecraft States with the initialization variables
scObject.hub.r_CN_NInit = rN # m - r_CN_N
scObject.hub.v_CN_NInit = vN # m - v_CN_N
scObject.hub.sigma_BNInit = sig_BN
simulationTime = macros.sec2nano(5.)
#
# Setup data logging before the simulation is initialized
#
numDataPoints = 10
# add BSK objects to the simulation process
scSim.AddModelToTask(simTaskName, scObject)
scSim.AddModelToTask(simTaskName, newAtmo)
scSim.AddModelToTask(simTaskName, newDrag)
# setup logging
dataLog = scObject.scStateOutMsg.recorder()
scSim.AddModelToTask(simTaskName, dataLog)
atmoLog = newAtmo.envOutMsgs[0].recorder()
scSim.AddModelToTask(simTaskName, atmoLog)
#
# initialize Simulation
#
scSim.InitializeSimulation()
scSim.AddVariableForLogging(newDrag.ModelTag + ".forceExternal_B",
simulationTimeStep, 0, 2, 'double')
scSim.AddVariableForLogging(newDrag.ModelTag + ".torqueExternalPntB_B",
simulationTimeStep, 0, 2, 'double')
# configure a simulation stop time time and execute the simulation run
#
scSim.ConfigureStopTime(simulationTime)
scSim.ExecuteSimulation()
# Retrieve logged data
dragDataForce_B = scSim.GetLogVariableData(newDrag.ModelTag + ".forceExternal_B")
dragTorqueData = scSim.GetLogVariableData(newDrag.ModelTag + ".torqueExternalPntB_B")
posData = dataLog.r_BN_N
velData = dataLog.v_BN_N
attData = dataLog.sigma_BN
densData = atmoLog.neutralDensity
np.set_printoptions(precision=16)
def checkFacetDragForce(dens, area, coeff, facet_dir, sigma_BN, inertial_vel):
dcm = rbk.MRP2C(sigma_BN)
vMag = np.linalg.norm(inertial_vel)
v_hat_B = dcm.dot(inertial_vel) / vMag
projArea = area * (facet_dir.dot(v_hat_B))
if projArea > 0:
drag_force = -0.5 * dens * projArea * coeff * vMag**2.0 * v_hat_B
else:
drag_force = np.zeros([3,])
return drag_force
# Compare to expected values
accuracy = 1e-3
unitTestSupport.writeTeXSnippet("toleranceValue", str(accuracy), path)
test_val = np.zeros([3,])
for i in range(len(scAreas)):
test_val += checkFacetDragForce(densData[i], scAreas[i], scCoeff[i], B_normals[i], attData[1], velData[1])
if len(densData) > 0:
if not unitTestSupport.isArrayEqualRelative(dragDataForce_B[1,1:4], test_val, 3,accuracy):
testFailCount += 1
testMessages.append(
"FAILED: FacetDragEffector failed force unit test at t=" + str(dragDataForce_B[1,0]* macros.NANO2SEC) + "sec with a value difference of "+str(dragDataForce_B[1,1:]-test_val))
else:
testFailCount += 1
testMessages.append("FAILED: ExpAtmo failed to pull any logged data")
if testFailCount:
print(testMessages)
else:
print("PASSED")
return testFailCount, testMessages
def TestShadowCalculation():
# Init test support variables
testFailCount = 0
testMessages = []
## Simulation initialization
simTaskName = "simTask"
simProcessName = "simProcess"
scSim = SimulationBaseClass.SimBaseClass()
dynProcess = scSim.CreateNewProcess(simProcessName)
simulationTimeStep = macros.sec2nano(10.)
dynProcess.addTask(scSim.CreateNewTask(simTaskName, simulationTimeStep))
# initialize spacecraft object and set properties
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
simpleNavObj = simpleNav.SimpleNav()
simpleNavObj.scStateInMsg.subscribeTo(scObject.scStateOutMsg)
## Initialize new atmosphere and drag model, add them to task
newAtmo = exponentialAtmosphere.ExponentialAtmosphere()
newAtmo.ModelTag = "ExpAtmo"
newAtmo.addSpacecraftToModel(scObject.scStateOutMsg)
newDrag = facetDragDynamicEffector.FacetDragDynamicEffector()
newDrag.ModelTag = "FacetDrag"
newDrag.atmoDensInMsg.subscribeTo(newAtmo.envOutMsgs[0])
scObject.addDynamicEffector(newDrag)
try:
scAreas = [1.0, 1.0]
scCoeff = np.array([2.0, 2.0])
B_normals = [np.array([0, 0, -1]), np.array([0, -1, 0])]
B_locations = [np.array([0,0,0.1]), np.array([0,0.1,0])]
for ind in range(0,len(scAreas)):
newDrag.addFacet(scAreas[ind], scCoeff[ind], B_normals[ind], B_locations[ind])
except:
testFailCount += 1
testMessages.append("ERROR: FacetDrag unit test failed while setting facet parameters.")
return testFailCount, testMessages
# clear prior gravitational body and SPICE setup definitions
gravFactory = simIncludeGravBody.gravBodyFactory()
planet = gravFactory.createEarth()
planet.isCentralBody = True # ensure this is the central gravitational body
mu = planet.mu
# attach gravity model to spacecraft
scObject.gravField.gravBodies = spacecraft.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
rN = np.array([r_eq+200.0e3,0,0])
vN = np.array([0,7.788e3,0])
sig_BN = np.array([0,0,0])
# initialize Spacecraft States with the initialization variables
scObject.hub.r_CN_NInit = rN # m - r_CN_N
scObject.hub.v_CN_NInit = vN # m - v_CN_N
scObject.hub.sigma_BNInit = sig_BN
simulationTime = macros.sec2nano(10.)
#
# Setup data logging before the simulation is initialized
#
numDataPoints = 10
# add BSK objects to the simulation process
scSim.AddModelToTask(simTaskName, scObject)
scSim.AddModelToTask(simTaskName, newAtmo)
scSim.AddModelToTask(simTaskName, newDrag)
# setup logging
dataLog = scObject.scStateOutMsg.recorder()
scSim.AddModelToTask(simTaskName, dataLog)
atmoLog = newAtmo.envOutMsgs[0].recorder()
scSim.AddModelToTask(simTaskName, atmoLog)
#
# initialize Simulation
#
scSim.InitializeSimulation()
scSim.AddVariableForLogging(newDrag.ModelTag + ".forceExternal_B",
simulationTimeStep, 0, 2, 'double')
scSim.AddVariableForLogging(newDrag.ModelTag + ".torqueExternalPntB_B",
simulationTimeStep, 0, 2, 'double')
# configure a simulation stop time time and execute the simulation run
#
scSim.ConfigureStopTime(simulationTime)
scSim.ExecuteSimulation()
# Retrieve logged data
#dragDataForce_B = scSim.GetLogVariableData(newDrag.ModelTag + ".forceExternal_B")
dragDataForce_B = scSim.GetLogVariableData(newDrag.ModelTag + ".forceExternal_B")
dragTorqueData = scSim.GetLogVariableData(newDrag.ModelTag + ".torqueExternalPntB_B")
posData = dataLog.r_BN_N
velData = dataLog.v_BN_N
attData = dataLog.sigma_BN
densData = atmoLog.neutralDensity
np.set_printoptions(precision=16)
# Compare to expected values
accuracy = 1e-9
#unitTestSupport.writeTeXSnippet("toleranceValue", str(accuracy), path)
if len(densData) > 0:
for ind in range(1,len(densData)):
if not unitTestSupport.isArrayZero(dragDataForce_B[ind, 1:], 3,accuracy):
testFailCount += 1
testMessages.append(
"FAILED: FacetDragEffector failed shadow unit test with a value difference of "
+ str(dragDataForce_B[ind,1:]))
else:
testFailCount += 1
testMessages.append("FAILED: ExpAtmo failed to pull any logged data")
if testFailCount:
print(testMessages)
else:
print("PASSED")
return testFailCount, testMessages
if __name__=="__main__":
# test_unitFacetDrag()
TestShadowCalculation()
# TestDragCalculation()