#
# 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 numpy as np
from Basilisk import __path__
from Basilisk.simulation import ephemerisConverter
from Basilisk.simulation import (spacecraft, extForceTorque, simpleNav,
reactionWheelStateEffector, coarseSunSensor, eclipse)
from Basilisk.simulation import thrusterDynamicEffector
from Basilisk.utilities import RigidBodyKinematics as rbk
from Basilisk.utilities import macros as mc
from Basilisk.utilities import simIncludeRW, simIncludeGravBody
from Basilisk.utilities import simIncludeThruster
from Basilisk.utilities import unitTestSupport as sp
bskPath = __path__[0]
[docs]class BSKDynamicModels():
"""
General bskSim simulation class that sets up the spacecraft simulation configuration.
"""
def __init__(self, SimBase, dynRate):
# define empty class variables
self.sun = None
self.earth = None
self.moon = None
self.epochMsg = None
self.RW1 = None
self.RW2 = None
self.RW3 = None
self.RW4 = None
# Define process name, task name and task time-step
self.processName = SimBase.DynamicsProcessName
self.taskName = "DynamicsTask"
self.processTasksTimeStep = mc.sec2nano(dynRate)
# Create task
SimBase.dynProc.addTask(SimBase.CreateNewTask(self.taskName, self.processTasksTimeStep))
# Instantiate Dyn modules as objects
self.scObject = spacecraft.Spacecraft()
self.gravFactory = simIncludeGravBody.gravBodyFactory()
self.rwFactory = simIncludeRW.rwFactory()
self.extForceTorqueObject = extForceTorque.ExtForceTorque()
self.simpleNavObject = simpleNav.SimpleNav()
self.eclipseObject = eclipse.Eclipse()
self.CSSConstellationObject = coarseSunSensor.CSSConstellation()
self.rwStateEffector = reactionWheelStateEffector.ReactionWheelStateEffector()
self.thrustersDynamicEffector = thrusterDynamicEffector.ThrusterDynamicEffector()
self.EarthEphemObject = ephemerisConverter.EphemerisConverter()
# Initialize all modules and write init one-time messages
self.InitAllDynObjects()
# Assign initialized modules to tasks
SimBase.AddModelToTask(self.taskName, self.scObject, 201)
SimBase.AddModelToTask(self.taskName, self.simpleNavObject, 109)
SimBase.AddModelToTask(self.taskName, self.gravFactory.spiceObject, 200)
SimBase.AddModelToTask(self.taskName, self.EarthEphemObject, 199)
SimBase.AddModelToTask(self.taskName, self.CSSConstellationObject, 108)
SimBase.AddModelToTask(self.taskName, self.eclipseObject, 204)
SimBase.AddModelToTask(self.taskName, self.rwStateEffector, 301)
SimBase.AddModelToTask(self.taskName, self.extForceTorqueObject, 300)
SimBase.createNewEvent("addOneTimeRWFault", self.processTasksTimeStep, True,
["self.TotalSim.CurrentNanos>=self.oneTimeFaultTime and self.oneTimeRWFaultFlag==1"],
["self.DynModels.AddRWFault('friction',0.05,1, self.TotalSim.CurrentNanos)", "self.oneTimeRWFaultFlag=0"])
SimBase.createNewEvent("addRepeatedRWFault", self.processTasksTimeStep, True,
["self.repeatRWFaultFlag==1"],
["self.DynModels.PeriodicRWFault(1./3000,'friction',0.005,1, self.TotalSim.CurrentNanos)", "self.setEventActivity('addRepeatedRWFault',True)"])
# ------------------------------------------------------------------------------------------- #
# These are module-initialization methods
[docs] def SetSpacecraftHub(self):
"""
Specify the spacecraft hub parameters.
"""
self.scObject.ModelTag = "bskSat"
# -- Crate a new variable for the sim sc inertia I_sc. Note: this is currently accessed from FSWClass
self.I_sc = [900., 0., 0.,
0., 800., 0.,
0., 0., 600.]
self.scObject.hub.mHub = 750.0 # kg - spacecraft mass
self.scObject.hub.r_BcB_B = [[0.0], [0.0], [0.0]] # m - position vector of body-fixed point B relative to CM
self.scObject.hub.IHubPntBc_B = sp.np2EigenMatrix3d(self.I_sc)
[docs] def SetGravityBodies(self):
"""
Specify what gravitational bodies to include in the simulation
"""
timeInitString = "2012 MAY 1 00:28:30.0"
gravBodies = self.gravFactory.createBodies(['sun', 'earth', 'moon'])
gravBodies['earth'].isCentralBody = True
self.sun = 0
self.earth = 1
self.moon = 2
self.gravFactory.addBodiesTo(self.scObject)
self.gravFactory.createSpiceInterface(bskPath + '/supportData/EphemerisData/',
timeInitString,
epochInMsg=True)
self.epochMsg = self.gravFactory.epochMsg
self.gravFactory.spiceObject.zeroBase = 'Earth'
self.EarthEphemObject.addSpiceInputMsg(self.gravFactory.spiceObject.planetStateOutMsgs[self.earth])
[docs] def SetEclipseObject(self):
"""
Specify what celestial object is causing an eclipse message.
"""
self.eclipseObject.ModelTag = "eclipseObject"
self.eclipseObject.sunInMsg.subscribeTo(self.gravFactory.spiceObject.planetStateOutMsgs[self.sun])
# add all celestial objects in spiceObjects except for the sun (0th object)
for c in range(1, len(self.gravFactory.spiceObject.planetStateOutMsgs)):
self.eclipseObject.addPlanetToModel(self.gravFactory.spiceObject.planetStateOutMsgs[c])
self.eclipseObject.addSpacecraftToModel(self.scObject.scStateOutMsg)
[docs] def SetExternalForceTorqueObject(self):
"""Set the external force and torque object."""
self.extForceTorqueObject.ModelTag = "externalDisturbance"
self.scObject.addDynamicEffector(self.extForceTorqueObject)
[docs] def SetSimpleNavObject(self):
"""Set the navigation sensor object."""
self.simpleNavObject.ModelTag = "SimpleNavigation"
self.simpleNavObject.scStateInMsg.subscribeTo(self.scObject.scStateOutMsg)
[docs] def SetReactionWheelDynEffector(self):
"""Set the 4 reaction wheel devices."""
# specify RW momentum capacity
maxRWMomentum = 50. # Nms
# Define orthogonal RW pyramid
# -- Pointing directions
rwElAngle = np.array([40.0, 40.0, 40.0, 40.0])*mc.D2R
rwAzimuthAngle = np.array([45.0, 135.0, 225.0, 315.0])*mc.D2R
rwPosVector = [[0.8, 0.8, 1.79070],
[0.8, -0.8, 1.79070],
[-0.8, -0.8, 1.79070],
[-0.8, 0.8, 1.79070]
]
gsHat = (rbk.Mi(-rwAzimuthAngle[0], 3).dot(rbk.Mi(rwElAngle[0], 2))).dot(np.array([1, 0, 0]))
self.RW1 = self.rwFactory.create('Honeywell_HR16',
gsHat,
maxMomentum=maxRWMomentum,
rWB_B=rwPosVector[0])
gsHat = (rbk.Mi(-rwAzimuthAngle[1], 3).dot(rbk.Mi(rwElAngle[1], 2))).dot(np.array([1, 0, 0]))
self.RW2 = self.rwFactory.create('Honeywell_HR16',
gsHat,
maxMomentum=maxRWMomentum,
rWB_B=rwPosVector[1])
gsHat = (rbk.Mi(-rwAzimuthAngle[2], 3).dot(rbk.Mi(rwElAngle[2], 2))).dot(np.array([1, 0, 0]))
self.RW3 = self.rwFactory.create('Honeywell_HR16',
gsHat,
maxMomentum=maxRWMomentum,
rWB_B=rwPosVector[2])
gsHat = (rbk.Mi(-rwAzimuthAngle[3], 3).dot(rbk.Mi(rwElAngle[3], 2))).dot(np.array([1, 0, 0]))
self.RW4 = self.rwFactory.create('Honeywell_HR16',
gsHat,
maxMomentum=maxRWMomentum,
rWB_B=rwPosVector[3])
self.rwFactory.addToSpacecraft("RWA", self.rwStateEffector, self.scObject)
[docs] def SetThrusterStateEffector(self):
"""Set the 8 ACS thrusters."""
# Make a fresh TH factory instance, this is critical to run multiple times
thFactory = simIncludeThruster.thrusterFactory()
# 8 thrusters are modeled that act in pairs to provide the desired torque
thPos = [
[825.5/1000.0, 880.3/1000.0, 1765.3/1000.0],
[825.5/1000.0, 880.3/1000.0, 260.4/1000.0],
[880.3/1000.0, 825.5/1000.0, 1765.3/1000.0],
[880.3/1000.0, 825.5/1000.0, 260.4/1000.0],
[-825.5/1000.0, -880.3/1000.0, 1765.3/1000.0],
[-825.5/1000.0, -880.3/1000.0, 260.4/1000.0],
[-880.3/1000.0, -825.5/1000.0, 1765.3/1000.0],
[-880.3/1000.0, -825.5/1000.0, 260.4/1000.0]
]
thDir = [
[0.0, -1.0, 0.0],
[0.0, -1.0, 0.0],
[-1.0, 0.0, 0.0],
[-1.0, 0.0, 0.0],
[0.0, 1.0, 0.0],
[0.0, 1.0, 0.0],
[1.0, 0.0, 0.0],
[1.0, 0.0, 0.0]
]
for pos_B, dir_B in zip(thPos, thDir):
thFactory.create(
'MOOG_Monarc_1'
, pos_B
, dir_B
)
# create thruster object container and tie to spacecraft object
thFactory.addToSpacecraft("ACS Thrusters",
self.thrustersDynamicEffector,
self.scObject)
[docs] def SetCSSConstellation(self):
"""Set the 8 CSS sensors"""
self.CSSConstellationObject.ModelTag = "cssConstellation"
def setupCSS(cssDevice):
cssDevice.fov = 80. * mc.D2R # half-angle field of view value
cssDevice.scaleFactor = 2.0
cssDevice.sunInMsg.subscribeTo(self.gravFactory.spiceObject.planetStateOutMsgs[self.sun])
cssDevice.stateInMsg.subscribeTo(self.scObject.scStateOutMsg)
cssDevice.sunEclipseInMsg.subscribeTo(self.eclipseObject.eclipseOutMsgs[0])
cssDevice.this.disown()
# setup CSS sensor normal vectors in body frame components
nHat_B_List = [
[0.0, 0.707107, 0.707107],
[0.707107, 0., 0.707107],
[0.0, -0.707107, 0.707107],
[-0.707107, 0., 0.707107],
[0.0, -0.965926, -0.258819],
[-0.707107, -0.353553, -0.612372],
[0., 0.258819, -0.965926],
[0.707107, -0.353553, -0.612372]
]
numCSS = len(nHat_B_List)
# store all
cssList = []
for nHat_B, i in zip(nHat_B_List, list(range(1,numCSS+1))):
CSS = coarseSunSensor.CoarseSunSensor()
setupCSS(CSS)
CSS.ModelTag = "CSS" + str(i)
CSS.nHat_B = np.array(nHat_B)
cssList.append(CSS)
# assign the list of CSS devices to the CSS array class
self.CSSConstellationObject.sensorList = coarseSunSensor.CSSVector(cssList)
# Method for adding reaction wheel faults
[docs] def PeriodicRWFault(self, probability, faultType, fault, faultRW, currentTime):
"""
Adds a fault periodically. Probability is the chance of the fault occurring per update.
"""
if np.random.uniform() < probability:
self.AddRWFault(faultType, fault, faultRW, currentTime)
[docs] def AddRWFault(self, faultType, fault, faultRW, currentTime):
"""
Adds a static friction fault to the reaction wheel.
"""
self.RWFaultLog.append([faultType, fault, faultRW, currentTime*mc.NANO2MIN])
if faultType == "friction":
if faultRW == 1:
self.RW1.fCoulomb += fault
elif faultRW == 2:
self.RW2.fCoulomb += fault
elif faultRW == 3:
self.RW3.fCoulomb += fault
elif faultRW == 4:
self.RW4.fCoulomb += fault
else:
print("Invalid fault type. No fault added.")
# Global call to initialize every module
[docs] def InitAllDynObjects(self):
"""
Initialize all the dynamics objects.
"""
self.SetSpacecraftHub()
self.SetGravityBodies()
self.SetExternalForceTorqueObject()
self.SetSimpleNavObject()
self.SetEclipseObject()
self.SetCSSConstellation()
self.SetReactionWheelDynEffector()
self.SetThrusterStateEffector()