Source code for BSK_Dynamics

''' '''
'''
 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.utilities import macros as mc
from Basilisk.utilities import unitTestSupport as sp
from Basilisk.simulation import (spacecraftPlus, gravityEffector, extForceTorque, simple_nav, spice_interface,
                                 reactionWheelStateEffector, coarse_sun_sensor, eclipse, imu_sensor)
from Basilisk.simulation import thrusterDynamicEffector
from Basilisk.utilities import unitTestSupport
from Basilisk.utilities import simIncludeThruster
from Basilisk.utilities import simIncludeRW, simIncludeGravBody
from Basilisk.utilities import RigidBodyKinematics as rbk
from Basilisk.pyswice import pyswice
from Basilisk import __path__
bskPath = __path__[0]



[docs]class BSKDynamicModels(): """ General bskSim simulation class that sets up the spacecraft simulation configuration. """ def __init__(self, SimBase, dynRate): # 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 = spacecraftPlus.SpacecraftPlus() self.gravFactory = simIncludeGravBody.gravBodyFactory() self.extForceTorqueObject = extForceTorque.ExtForceTorque() self.simpleNavObject = simple_nav.SimpleNav() self.eclipseObject = eclipse.Eclipse() self.CSSConstellationObject = coarse_sun_sensor.CSSConstellation() self.rwStateEffector = reactionWheelStateEffector.ReactionWheelStateEffector() self.thrustersDynamicEffector = thrusterDynamicEffector.ThrusterDynamicEffector() # Initialize all modules and write init one-time messages self.InitAllDynObjects() self.WriteInitDynMessages(SimBase) # Assign initialized modules to tasks SimBase.AddModelToTask(self.taskName, self.scObject, None, 201) SimBase.AddModelToTask(self.taskName, self.simpleNavObject, None, 109) SimBase.AddModelToTask(self.taskName, self.gravFactory.spiceObject, 200) SimBase.AddModelToTask(self.taskName, self.CSSConstellationObject, None, 108) SimBase.AddModelToTask(self.taskName, self.eclipseObject, None, 204) SimBase.AddModelToTask(self.taskName, self.rwStateEffector, None, 301) SimBase.AddModelToTask(self.taskName, self.extForceTorqueObject, None, 300) # ------------------------------------------------------------------------------------------- # # 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) self.scObject.scStateOutMsgName = "inertial_state_output"
[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(['earth', 'sun', 'moon']) gravBodies['earth'].isCentralBody = True self.scObject.gravField.gravBodies = spacecraftPlus.GravBodyVector(list(self.gravFactory.gravBodies.values())) spiceObject, epochMsg = self.gravFactory.createSpiceInterface(bskPath + '/supportData/EphemerisData/', timeInitString, epochInMsgName = 'simEpoch') self.epochMsg = epochMsg self.gravFactory.spiceObject.zeroBase = 'Earth' pyswice.furnsh_c(self.gravFactory.spiceObject.SPICEDataPath + 'de430.bsp') # solar system bodies pyswice.furnsh_c(self.gravFactory.spiceObject.SPICEDataPath + 'naif0012.tls') # leap second file pyswice.furnsh_c(self.gravFactory.spiceObject.SPICEDataPath + 'de-403-masses.tpc') # solar system masses pyswice.furnsh_c(self.gravFactory.spiceObject.SPICEDataPath + 'pck00010.tpc') # generic Planetary Constants Kernel
[docs] def SetEclipseObject(self): """ Specify what celestial object is causing an eclipse message. """ self.eclipseObject.sunInMsgName = 'sun_planet_data' self.eclipseObject.addPlanetName('earth') self.eclipseObject.addPositionMsgName(self.scObject.scStateOutMsgName)
[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"
[docs] def SetReactionWheelDynEffector(self): """Set the 4 reaction wheel devices.""" # Make a fresh RW factory instance, this is critical to run multiple times self.rwFactory = simIncludeRW.rwFactory() # 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] ] for elAngle, azAngle, posVector in zip(rwElAngle, rwAzimuthAngle, rwPosVector): gsHat = (rbk.Mi(-azAngle,3).dot(rbk.Mi(elAngle,2))).dot(np.array([1,0,0])) self.rwFactory.create('Honeywell_HR16', gsHat, maxMomentum=maxRWMomentum, rWB_B=posVector) self.rwFactory.addToSpacecraft(self.scObject.ModelTag, 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("Thrusters", self.thrustersDynamicEffector, self.scObject)
[docs] def SetCSSConstellation(self): """Set the 8 CSS sensors""" self.CSSConstellationObject.ModelTag = "cssConstellation" self.CSSConstellationObject.outputConstellationMessage = "CSSConstellation_output" # define single CSS element CSS_default = coarse_sun_sensor.CoarseSunSensor() CSS_default.fov = 80. * mc.D2R # half-angle field of view value CSS_default.scaleFactor = 2.0 # 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 = coarse_sun_sensor.CoarseSunSensor(CSS_default) CSS.ModelTag = "CSS" + str(i) + "_sensor" CSS.cssDataOutMsgName = "CSS" + str(i) + "_output" CSS.nHat_B = np.array(nHat_B) CSS.sunEclipseInMsgName = "eclipse_data_0" cssList.append(CSS) # assign the list of CSS devices to the CSS array class self.CSSConstellationObject.sensorList = coarse_sun_sensor.CSSVector(cssList)
# 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()
# Global call to create every required one-time message
[docs] def WriteInitDynMessages(self, SimBase): """Write out the required dynamics configuration messages.""" unitTestSupport.setMessage(SimBase.TotalSim, SimBase.DynamicsProcessName, self.gravFactory.spiceObject.epochInMsgName, self.epochMsg) return