# 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 gc
import inspect
import os
import warnings
import matplotlib.pyplot as plt
import numpy as np
import pytest
from Basilisk.architecture import messaging
from Basilisk.simulation import fuelTank
from Basilisk.simulation import gravityEffector
from Basilisk.simulation import linearSpringMassDamper
from Basilisk.simulation import spacecraft
from Basilisk.simulation import thrusterDynamicEffector, thrusterStateEffector
from Basilisk.utilities import RigidBodyKinematics as rbk
from Basilisk.utilities import SimulationBaseClass
from Basilisk.utilities import deprecated
from Basilisk.utilities import macros
from Basilisk.utilities import simIncludeThruster
from Basilisk.utilities import simHelpers
filename = inspect.getframeinfo(inspect.currentframe()).filename
path = os.path.dirname(os.path.abspath(filename))
def _usesExpiredDeprecation(accessor, message):
"""Return true if deprecated public access has reached the urgent warning phase."""
expectedWarnings = (deprecated.BSKDeprecationWarning, deprecated.BSKUrgentDeprecationWarning)
with pytest.warns(expectedWarnings, match=message) as warningList:
accessor()
return any(issubclass(w.category, deprecated.BSKUrgentDeprecationWarning) for w in warningList)
def _configureTankGeometry(tankModel):
if hasattr(tankModel, "radiusTankInit"):
tankModel.radiusTankInit = 1.0 # [m]
if hasattr(tankModel, "lengthTank"):
tankModel.lengthTank = 1.0 # [m]
[docs]
@pytest.mark.parametrize("thrusterConstructor", [thrusterDynamicEffector.ThrusterDynamicEffector,
thrusterStateEffector.ThrusterStateEffector])
def test_massDepletionTest(show_plots, thrusterConstructor):
"""Module Unit Test"""
# The __tracebackhide__ setting influences pytest showing of tracebacks:
# the mrp_steering_tracking() function will not be shown unless the
# --fulltrace command line option is specified.
__tracebackhide__ = True
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
unitTaskName = "unitTask"
unitProcessName = "TestProcess"
# Create a sim module as an empty container
unitTestSim = SimulationBaseClass.SimBaseClass()
# Create test thread
testProcessRate = macros.sec2nano(0.1) # [s]
testProc = unitTestSim.CreateNewProcess(unitProcessName)
testProc.addTask(unitTestSim.CreateNewTask(unitTaskName, testProcessRate))
# add thruster devices
thFactory = simIncludeThruster.thrusterFactory()
thFactory.create(
'TEST_Thruster',
[1, 0, 0], # location in B-frame
[0, 1, 0] # direction in B-frame
)
# create thruster object container and tie to spacecraft object
thrustersEffector = thrusterConstructor()
thFactory.addToSpacecraft("Thrusters", thrustersEffector, scObject)
unitTestSim.fuelTankStateEffector = fuelTank.FuelTank()
tankModel = fuelTank.FuelTankModelConstantVolume()
unitTestSim.fuelTankStateEffector.setTankModel(tankModel)
initialFuelMass = 40.0 # [kg]
tankModel.propMassInit = initialFuelMass
tankModel.r_TcT_TInit = [[0.0], [0.0], [0.0]]
unitTestSim.fuelTankStateEffector.setR_TB_B([[0.0], [0.0], [0.0]]) # [m]
tankModel.radiusTankInit = 46.0 / 2.0 / 3.2808399 / 12.0
# Add tank
scObject.addStateEffector(unitTestSim.fuelTankStateEffector)
unitTestSim.fuelTankStateEffector.addThrusterSet(thrustersEffector)
# set thruster commands
ThrustMessage = messaging.THRArrayOnTimeCmdMsgPayload()
ThrustMessage.OnTimeRequest = [9.9]
thrCmdMsg = messaging.THRArrayOnTimeCmdMsg().write(ThrustMessage)
thrustersEffector.cmdsInMsg.subscribeTo(thrCmdMsg)
# Add test module to runtime call list
unitTestSim.AddModelToTask(unitTaskName, unitTestSim.fuelTankStateEffector)
unitTestSim.AddModelToTask(unitTaskName, thrustersEffector)
unitTestSim.AddModelToTask(unitTaskName, scObject)
unitTestSim.earthGravBody = gravityEffector.GravBodyData()
unitTestSim.earthGravBody.planetName = "earth_planet_data"
unitTestSim.earthGravBody.mu = 0.3986004415E+15 # meters
unitTestSim.earthGravBody.isCentralBody = True
scObject.gravField.gravBodies = spacecraft.GravBodyVector([unitTestSim.earthGravBody])
dataLog = scObject.scStateOutMsg.recorder()
fuelLog = unitTestSim.fuelTankStateEffector.fuelTankOutMsg.recorder()
thrLog = thrustersEffector.thrusterOutMsgs[0].recorder()
unitTestSim.AddModelToTask(unitTaskName, dataLog)
unitTestSim.AddModelToTask(unitTaskName, fuelLog)
unitTestSim.AddModelToTask(unitTaskName, thrLog)
scObject.hub.mHub = 750.0
scObject.hub.r_BcB_B = [[0.0], [0.0], [0.0]]
scObject.hub.IHubPntBc_B = [[900.0, 0.0, 0.0], [0.0, 800.0, 0.0], [0.0, 0.0, 600.0]]
scObject.hub.r_CN_NInit = [[-4020338.690396649], [7490566.741852513], [5248299.211589362]]
scObject.hub.v_CN_NInit = [[-5199.77710904224], [-3436.681645356935], [1041.576797498721]]
scObject.hub.sigma_BNInit = [[0.1], [0.2], [-0.3]]
scObject.hub.omega_BN_BInit = [[0.001], [-0.01], [0.03]]
scObjectLog = scObject.logger(["totOrbAngMomPntN_N", "totRotAngMomPntC_N", "totRotEnergy"])
unitTestSim.AddModelToTask(unitTaskName, scObjectLog)
unitTestSim.InitializeSimulation()
posRef = scObject.dynManager.getStateObject(scObject.hub.nameOfHubPosition)
sigmaRef = scObject.dynManager.getStateObject(scObject.hub.nameOfHubSigma)
stopTime = 60.0 * 10.0
unitTestSim.ConfigureStopTime(macros.sec2nano(stopTime))
unitTestSim.ExecuteSimulation()
orbAngMom_N = simHelpers.addTimeColumn(scObjectLog.times(), scObjectLog.totOrbAngMomPntN_N)
rotAngMom_N = simHelpers.addTimeColumn(scObjectLog.times(), scObjectLog.totRotAngMomPntC_N)
rotEnergy = simHelpers.addTimeColumn(scObjectLog.times(), scObjectLog.totRotEnergy)
thrust = thrLog.thrustForce_B
thrustPercentage = thrLog.thrustFactor
fuelMass = fuelLog.fuelMass
fuelMassDot = fuelLog.fuelMassDot
plt.close("all")
plt.figure(1)
plt.plot(orbAngMom_N[:, 0] * 1e-9, orbAngMom_N[:, 1] - orbAngMom_N[0, 1], orbAngMom_N[:, 0] * 1e-9,
orbAngMom_N[:, 2] - orbAngMom_N[0, 2], orbAngMom_N[:, 0] * 1e-9, orbAngMom_N[:, 3] - orbAngMom_N[0, 3])
plt.title("Change in Orbital Angular Momentum")
plt.figure(2)
plt.plot(rotAngMom_N[:, 0] * 1e-9, rotAngMom_N[:, 1] - rotAngMom_N[0, 1], rotAngMom_N[:, 0] * 1e-9,
rotAngMom_N[:, 2] - rotAngMom_N[0, 2], rotAngMom_N[:, 0] * 1e-9, rotAngMom_N[:, 3] - rotAngMom_N[0, 3])
plt.title("Change in Rotational Angular Momentum")
plt.figure(3)
plt.plot(rotEnergy[:, 0] * 1e-9, rotEnergy[:, 1] - rotEnergy[0, 1])
plt.title("Change in Rotational Energy")
plt.figure(4)
plt.plot(thrLog.times() * 1e-9, thrust[:, 0], thrLog.times() * 1e-9, thrust[:, 1], thrLog.times() * 1e-9,
thrust[:, 2])
plt.xlim([0, 20])
plt.ylim([0, 1])
plt.title("Thrust")
plt.figure(5)
plt.plot(thrLog.times() * 1e-9, thrustPercentage)
plt.xlim([0, 20])
plt.ylim([0, 1.1])
plt.title("Thrust Percentage")
plt.figure(6)
plt.plot(fuelLog.times() * 1e-9, fuelMass)
plt.xlim([0, 20])
plt.title("Fuel Mass")
plt.figure(7)
plt.plot(fuelLog.times() * 1e-9, fuelMassDot)
plt.xlim([0, 20])
plt.title("Fuel Mass Dot")
if show_plots:
plt.show()
plt.close('all')
dataPos = posRef.getState()
dataSigma = sigmaRef.getState()
dataPos = [[dataPos[0][0], dataPos[1][0], dataPos[2][0]]]
dataSigma = [[dataSigma[0][0], dataSigma[1][0], dataSigma[2][0]]]
if thrustersEffector.__class__.__name__ == "ThrusterDynamicEffector":
truePos = [[-6.7815933935338277e+06, 4.9468685979815889e+06, 5.4867416696776701e+06]]
trueSigma = [[1.4401781243854264e-01, -6.4168702021364002e-02, 3.0166086824900967e-01]]
elif thrustersEffector.__class__.__name__ == "ThrusterStateEffector":
truePos = [[-6781593.400948599, 4946868.619447934, 5486741.690842073]]
trueSigma = [[0.14366625871003397, -0.06488330854626220, 0.3032637107362375]]
for i in range(0, len(truePos)):
np.testing.assert_allclose(dataPos[i], truePos[i], rtol=1e-6, err_msg="Thruster position not equal")
for i in range(0, len(trueSigma)):
# check a vector values
np.testing.assert_allclose(dataSigma[i], trueSigma[i], rtol=1e-4, err_msg="Thruster attitude not equal")
# target value computed from MaxThrust / (EARTH_GRAV * steadyIsp)
np.testing.assert_allclose(fuelMassDot[100], -0.000403404216123, rtol=1e-3,
err_msg="Thruster mass depletion not ramped up")
np.testing.assert_allclose(fuelMassDot[-1], 0, rtol=1e-12, err_msg="Thruster mass depletion not ramped down")
[docs]
@pytest.mark.parametrize("sloshMass", [0.0, 10.0, 40.0])
def test_leakyTank(sloshMass):
"""A leaking tank sheds mDot*t from the vehicle, whatever share of it fuel slosh carries."""
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
unitTaskName = "unitTask"
unitProcessName = "TestProcess"
# Create a sim module as an empty container
unitTestSim = SimulationBaseClass.SimBaseClass()
# Create test thread
testProcessRate = macros.sec2nano(0.1) # [s]
testProc = unitTestSim.CreateNewProcess(unitProcessName)
testProc.addTask(unitTestSim.CreateNewTask(unitTaskName, testProcessRate))
# Make Fuel Tank
unitTestSim.fuelTankStateEffector = fuelTank.FuelTank()
tankModel = fuelTank.FuelTankModelConstantVolume()
unitTestSim.fuelTankStateEffector.setTankModel(tankModel)
initialFuelMass = 40.0 # [kg]
tankModel.propMassInit = initialFuelMass
# Add tank
scObject.addStateEffector(unitTestSim.fuelTankStateEffector)
# Carry part of the propellant outside the tank, in an attached fuel slosh particle
particle = None
if sloshMass > 0.0:
particle = linearSpringMassDamper.LinearSpringMassDamper()
particle.k = 100.0 # [N/m]
particle.c = 1.0 # [N*s/m]
particle.r_PB_B = [[0.0], [0.0], [0.0]] # [m]
particle.pHat_B = [[1.0], [0.0], [0.0]]
particle.rhoInit = 0.0 # [m]
particle.rhoDotInit = 0.0 # [m/s]
particle.massInit = sloshMass # [kg]
unitTestSim.fuelTankStateEffector.pushFuelSloshParticle(particle)
scObject.addStateEffector(particle)
totalPropellant = initialFuelMass + sloshMass # [kg]
# Make the tank leaky
leakRate = 1e-5 # [kg/s]
unitTestSim.fuelTankStateEffector.setFuelLeakRate(leakRate)
# Add test module to runtime call list
unitTestSim.AddModelToTask(unitTaskName, unitTestSim.fuelTankStateEffector)
unitTestSim.AddModelToTask(unitTaskName, scObject)
fuelLog = unitTestSim.fuelTankStateEffector.fuelTankOutMsg.recorder()
unitTestSim.AddModelToTask(unitTaskName, fuelLog)
unitTestSim.InitializeSimulation()
stopTime = 1000.0 # [s]
unitTestSim.ConfigureStopTime(macros.sec2nano(stopTime))
unitTestSim.ExecuteSimulation()
fuelMass = fuelLog.fuelMass
fuelMassDot = fuelLog.fuelMassDot
assert np.allclose(fuelMassDot, -leakRate, rtol=1e-6)
# The tank drains only its share of the flow, so its mass follows
# m(t) = m(0) * (1 - mDot*t/totalPropellant), which is m(0) - mDot*t when it carries it all.
expectedTankMass = initialFuelMass * (1.0 - leakRate * stopTime / totalPropellant) # [kg]
assert np.isclose(fuelMass[-1], expectedTankMass, rtol=1e-6)
# Whatever the split, the vehicle sheds exactly mDot*t.
finalTankMass = scObject.dynManager.getStateObject(
unitTestSim.fuelTankStateEffector.getNameOfMassState()).getState()[0][0]
finalSloshMass = 0.0 if particle is None else scObject.dynManager.getStateObject(
particle.nameOfMassState).getState()[0][0]
shed = totalPropellant - (finalTankMass + finalSloshMass) # [kg]
assert np.isclose(shed, leakRate * stopTime, rtol=1e-6)
[docs]
@pytest.mark.parametrize("tankModelConstructor", [fuelTank.FuelTankModelConstantVolume,
fuelTank.FuelTankModelConstantDensity,
fuelTank.FuelTankModelEmptying,
fuelTank.FuelTankModelUniformBurn,
fuelTank.FuelTankModelCentrifugalBurn])
def test_leakyTankRunsOutOfFuel(tankModelConstructor):
"""Module Unit Test"""
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
unitTaskName = "unitTask"
unitProcessName = "TestProcess"
# Create a sim module as an empty container
unitTestSim = SimulationBaseClass.SimBaseClass()
# Create test thread
testProcessRate = macros.sec2nano(0.1) # [s]
testProc = unitTestSim.CreateNewProcess(unitProcessName)
testProc.addTask(unitTestSim.CreateNewTask(unitTaskName, testProcessRate))
# Make Fuel Tank
unitTestSim.fuelTankStateEffector = fuelTank.FuelTank()
tankModel = tankModelConstructor()
_configureTankGeometry(tankModel)
unitTestSim.fuelTankStateEffector.setTankModel(tankModel)
initialFuelMass = 1.0e-4 # [kg]
tankModel.propMassInit = initialFuelMass
# Add tank
scObject.addStateEffector(unitTestSim.fuelTankStateEffector)
# Make the tank leaky
leakRate = 1.0e-5 # [kg/s]
unitTestSim.fuelTankStateEffector.setFuelLeakRate(leakRate)
# Add test module to runtime call list
unitTestSim.AddModelToTask(unitTaskName, unitTestSim.fuelTankStateEffector)
unitTestSim.AddModelToTask(unitTaskName, scObject)
fuelLog = unitTestSim.fuelTankStateEffector.fuelTankOutMsg.recorder()
unitTestSim.AddModelToTask(unitTaskName, fuelLog)
unitTestSim.InitializeSimulation()
stopTime = 20.0 # [s]
unitTestSim.ConfigureStopTime(macros.sec2nano(stopTime))
unitTestSim.ExecuteSimulation()
fuelMass = fuelLog.fuelMass
fuelMassDot = fuelLog.fuelMassDot
fuelMassTolerance = 1e-14 # [kg]
fuelMassDotTolerance = 1e-14 # [kg/s]
assert np.all(np.isfinite(fuelMass))
assert np.all(np.isfinite(fuelMassDot))
assert np.all(fuelMass >= -fuelMassTolerance)
assert np.isclose(fuelMass[-1], 0.0, atol=fuelMassTolerance)
assert np.isclose(fuelMassDot[-1], 0.0, atol=fuelMassDotTolerance)
assert np.any(np.isclose(fuelMassDot, -leakRate, rtol=1e-6))
[docs]
@pytest.mark.parametrize("tankModelConstructor", [fuelTank.FuelTankModelConstantVolume,
fuelTank.FuelTankModelConstantDensity,
fuelTank.FuelTankModelEmptying,
fuelTank.FuelTankModelUniformBurn,
fuelTank.FuelTankModelCentrifugalBurn])
def test_tankModelOutlivesPythonReference(tankModelConstructor):
"""Regression test for issue #282.
The tank model is created in Python and handed to the FuelTank via
setTankModel(). Because the model is now held by a std::shared_ptr, dropping
the only Python reference must NOT free the underlying C++ object: the tank
co-owns it. Before the shared_ptr conversion the C++ member was a raw pointer,
so this sequence left a dangling pointer (undefined behaviour). Here we drop
the Python reference (del + gc.collect()) before the simulation runs and
assert the model still drives correct, finite depletion results.
"""
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
unitTaskName = "unitTask"
unitProcessName = "TestProcess"
unitTestSim = SimulationBaseClass.SimBaseClass()
testProcessRate = macros.sec2nano(0.1) # [s]
testProc = unitTestSim.CreateNewProcess(unitProcessName)
testProc.addTask(unitTestSim.CreateNewTask(unitTaskName, testProcessRate))
unitTestSim.fuelTankStateEffector = fuelTank.FuelTank()
tankModel = tankModelConstructor()
_configureTankGeometry(tankModel)
tankModel.propMassInit = 1.0e-4 # [kg]
unitTestSim.fuelTankStateEffector.setTankModel(tankModel)
# Drop the only Python reference to the model before the sim runs. With a
# raw pointer this orphaned the C++ object; with shared_ptr the tank keeps it.
del tankModel
gc.collect()
scObject.addStateEffector(unitTestSim.fuelTankStateEffector)
leakRate = 1.0e-5 # [kg/s]
unitTestSim.fuelTankStateEffector.setFuelLeakRate(leakRate)
unitTestSim.AddModelToTask(unitTaskName, unitTestSim.fuelTankStateEffector)
unitTestSim.AddModelToTask(unitTaskName, scObject)
fuelLog = unitTestSim.fuelTankStateEffector.fuelTankOutMsg.recorder()
unitTestSim.AddModelToTask(unitTaskName, fuelLog)
unitTestSim.InitializeSimulation()
stopTime = 20.0 # [s]
unitTestSim.ConfigureStopTime(macros.sec2nano(stopTime))
unitTestSim.ExecuteSimulation()
fuelMass = fuelLog.fuelMass
fuelMassDot = fuelLog.fuelMassDot
# If the model had been freed, these would be garbage / NaN or the sim would crash.
assert np.all(np.isfinite(fuelMass))
assert np.all(np.isfinite(fuelMassDot))
assert np.any(np.isclose(fuelMassDot, -leakRate, rtol=1e-6))
[docs]
def test_deprecatedPublicVariables():
"""Module Unit Test"""
tank = fuelTank.FuelTank()
dcm_TB = np.eye(3)
r_TB_B = [[1.0], [2.0], [3.0]] # [m]
fuelLeakRate = 2.0e-5 # [kg/s]
nameOfMassState = "fuelTankMassDeprecated"
expiredDeprecation = False
expiredDeprecation |= _usesExpiredDeprecation(
lambda: setattr(tank, "nameOfMassState", nameOfMassState),
"setNameOfMassState"
)
assert tank.getNameOfMassState() == nameOfMassState
expiredDeprecation |= _usesExpiredDeprecation(lambda: getattr(tank, "nameOfMassState"), "getNameOfMassState")
expiredDeprecation |= _usesExpiredDeprecation(lambda: setattr(tank, "dcm_TB", dcm_TB), "setDcm_TB")
np.testing.assert_allclose(tank.getDcm_TB(), dcm_TB, rtol=1e-15)
expiredDeprecation |= _usesExpiredDeprecation(lambda: getattr(tank, "dcm_TB"), "getDcm_TB")
expiredDeprecation |= _usesExpiredDeprecation(lambda: setattr(tank, "r_TB_B", r_TB_B), "setR_TB_B")
np.testing.assert_allclose(tank.getR_TB_B(), r_TB_B, rtol=1e-15)
expiredDeprecation |= _usesExpiredDeprecation(lambda: getattr(tank, "r_TB_B"), "getR_TB_B")
expiredDeprecation |= _usesExpiredDeprecation(lambda: setattr(tank, "updateOnly", False), "setUpdateOnly")
assert tank.getUpdateOnly() is False
expiredDeprecation |= _usesExpiredDeprecation(lambda: getattr(tank, "updateOnly"), "getUpdateOnly")
expiredDeprecation |= _usesExpiredDeprecation(
lambda: setattr(tank, "fuelLeakRate", fuelLeakRate),
"setFuelLeakRate"
)
assert tank.getFuelLeakRate() == pytest.approx(fuelLeakRate)
expiredDeprecation |= _usesExpiredDeprecation(lambda: getattr(tank, "fuelLeakRate"), "getFuelLeakRate")
if expiredDeprecation:
warnings.warn(
"The cutoff date for deprecated FuelTank public variable access has passed. "
"Remove the deprecated direct Python access to nameOfMassState, dcm_TB, r_TB_B, "
"updateOnly, and fuelLeakRate from fuelTank.i and update this compatibility test.",
UserWarning,
stacklevel=1
)
[docs]
def test_depletionTorqueFollowsTankMounting():
"""A rotated, offset, depleting tank must spin a resting hub up about r_TB_B x dcm_TB^T k3."""
dcm_TB = rbk.MRP2C([0.15, -0.25, 0.1])
r_TB_B = np.array([0.6, 0.0, 0.4]) # [m]
unitTestSim = SimulationBaseClass.SimBaseClass()
testProc = unitTestSim.CreateNewProcess("TestProcess")
testProc.addTask(unitTestSim.CreateNewTask("unitTask", macros.sec2nano(0.1)))
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
scObject.hub.mHub = 500.0 # [kg]
scObject.hub.r_BcB_B = [[0.0], [0.0], [0.0]] # [m]
# isotropic keeps the torque axis an eigenvector, so the hub rate holds exactly on it
scObject.hub.IHubPntBc_B = [[300.0, 0.0, 0.0], [0.0, 300.0, 0.0], [0.0, 0.0, 300.0]] # [kg*m^2]
scObject.hub.sigma_BNInit = [[0.0], [0.0], [0.0]]
scObject.hub.omega_BN_BInit = [[0.0], [0.0], [0.0]] # [rad/s]
tank = fuelTank.FuelTank()
tankModel = fuelTank.FuelTankModelEmptying()
tankModel.propMassInit = 200.0 # [kg]
tankModel.r_TcT_TInit = [[0.0], [0.0], [0.0]] # [m]
tankModel.radiusTankInit = 0.5 # [m]
tank.setTankModel(tankModel)
tank.setDcm_TB(dcm_TB.tolist())
tank.setR_TB_B(r_TB_B.reshape(3, 1).tolist())
tank.setUpdateOnly(False)
tank.setFuelLeakRate(1.0) # [kg/s]
scObject.addStateEffector(tank)
unitTestSim.AddModelToTask("unitTask", scObject)
unitTestSim.AddModelToTask("unitTask", tank)
dataLog = scObject.scStateOutMsg.recorder()
unitTestSim.AddModelToTask("unitTask", dataLog)
unitTestSim.InitializeSimulation()
unitTestSim.ConfigureStopTime(macros.sec2nano(20.0))
unitTestSim.ExecuteSimulation()
omega_BN_B = np.array(dataLog.omega_BN_B)[-1] # [rad/s]
k3_B = dcm_TB.transpose() @ np.array([0.0, 0.0, 1.0])
expectedAxis = np.cross(r_TB_B, k3_B)
expectedAxis /= np.linalg.norm(expectedAxis)
np.testing.assert_allclose(omega_BN_B / np.linalg.norm(omega_BN_B), -expectedAxis, atol=1e-6)
# Regression value after independently validating the emptying-model derivatives by finite differences.
np.testing.assert_allclose(
np.linalg.norm(omega_BN_B),
2.6376706988e-04, # [rad/s]
rtol=1e-5,
err_msg="depletion torque magnitude not equal")
[docs]
def test_depletionTorqueUsesCurrentMassFlowRate():
"""A ramping leak must drive the depletion torque from the current mass-flow rate, not the
previous integrator substep's, so an offset emptying tank under a time-varying flow reaches a
hub rate the stale substep rate would miss."""
dcm_TB = rbk.MRP2C([0.15, -0.25, 0.1])
r_TB_B = np.array([0.6, 0.0, 0.4]) # [m]
dt = 0.1 # [s]
unitTestSim = SimulationBaseClass.SimBaseClass()
testProc = unitTestSim.CreateNewProcess("TestProcess")
testProc.addTask(unitTestSim.CreateNewTask("unitTask", macros.sec2nano(dt)))
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "spacecraftBody"
scObject.hub.mHub = 500.0 # [kg]
scObject.hub.r_BcB_B = [[0.0], [0.0], [0.0]] # [m]
# isotropic keeps the torque axis an eigenvector, so the hub rate holds exactly on it
scObject.hub.IHubPntBc_B = [[300.0, 0.0, 0.0], [0.0, 300.0, 0.0], [0.0, 0.0, 300.0]] # [kg*m^2]
scObject.hub.sigma_BNInit = [[0.0], [0.0], [0.0]]
scObject.hub.omega_BN_BInit = [[0.0], [0.0], [0.0]] # [rad/s]
tank = fuelTank.FuelTank()
tankModel = fuelTank.FuelTankModelEmptying()
tankModel.propMassInit = 300.0 # [kg]
tankModel.r_TcT_TInit = [[0.0], [0.0], [0.0]] # [m]
tankModel.radiusTankInit = 0.5 # [m]
tank.setTankModel(tankModel)
tank.setDcm_TB(dcm_TB.tolist())
tank.setR_TB_B(r_TB_B.reshape(3, 1).tolist())
tank.setUpdateOnly(False)
# Drive the leak rate from an input message so it can be ramped across the run
leakPayload = messaging.MassFlowRateMsgPayload()
leakMsg = messaging.MassFlowRateMsg()
tank.fuelLeakRateInMsg.subscribeTo(leakMsg)
scObject.addStateEffector(tank)
unitTestSim.AddModelToTask("unitTask", scObject)
unitTestSim.AddModelToTask("unitTask", tank)
dataLog = scObject.scStateOutMsg.recorder()
unitTestSim.AddModelToTask("unitTask", dataLog)
unitTestSim.InitializeSimulation()
# Linearly ramp the leak rate as mDot(t) = 1 + 0.5 t [kg/s], rewriting the message each step so the
# tank mass rate changes over time and the substep lag in the mDot term becomes observable.
baseRate = 1.0 # [kg/s]
rampRate = 0.5 # [kg/s^2]
stopTime = 15.0 # [s]
for step in range(int(round(stopTime / dt))):
leakPayload.massFlowRate = baseRate + rampRate * step * dt # [kg/s]
leakMsg.write(leakPayload)
unitTestSim.ConfigureStopTime(macros.sec2nano((step + 1) * dt))
unitTestSim.ExecuteSimulation()
omega_BN_B = np.array(dataLog.omega_BN_B)[-1] # [rad/s]
k3_B = dcm_TB.transpose() @ np.array([0.0, 0.0, 1.0])
expectedAxis = np.cross(r_TB_B, k3_B)
expectedAxis /= np.linalg.norm(expectedAxis)
np.testing.assert_allclose(omega_BN_B / np.linalg.norm(omega_BN_B), -expectedAxis, atol=1e-6)
# Regression value after independently validating the emptying-model derivatives by finite differences.
np.testing.assert_allclose(
np.linalg.norm(omega_BN_B),
1.5638822750e-03, # [rad/s]
rtol=1e-5,
err_msg="depletion torque did not use the current mass-flow rate")
if __name__ == "__main__":
test_massDepletionTest(True, thrusterDynamicEffector.ThrusterDynamicEffector)
test_deprecatedPublicVariables()