#
# 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.
#
r"""
Overview
--------
Illustrates how to add a :ref:`ReactionWheelPower` to the simulation to track the RW power usages. Further,
a the RW power modules are connected to a battery to illustrate the energy usage during this maneuver.
This script expands on :ref:`scenarioAttitudeFeedbackRW`.
The script is found in the folder ``basilisk/examples`` and executed by using::
python3 scenarioAttitudeFeedbackRWPower.py
The simulation layout is shown in the following illustration. A single simulation process is created
which contains both the spacecraft simulation modules, as well as the Flight Software (FSW) algorithm
modules. The 3 separate :ref:`ReactionWheelPower` instances are created to model the RW power requirements.
For more examples on using the RW power module see :ref:`test_unitReactionWheelPower`.
Next, a battery module is created
using :ref:`simpleBattery`. All the RW power draw messages are connected to the battery to model the total
energy usage.
.. image:: /_images/static/test_scenarioAttitudeFeedbackRWPower.svg
:align: center
Illustration of Simulation Results
----------------------------------
The first simulation scenario is run with ``useRwPowerGeneration = False`` to model RW devices which require
electrical power to accelerate and decelerate the fly wheels. The attitude history should be the same
as in :ref:`scenarioAttitudeFeedbackRW`. Shown below are the resulting RW power requirements, as well as the
time history of the battery state.
::
show_plots = True, useRwPowerGeneration = False
.. image:: /_images/Scenarios/scenarioAttitudeFeedbackRWPower3False.svg
:align: center
.. image:: /_images/Scenarios/scenarioAttitudeFeedbackRWPower4False.svg
:align: center
The next simulation allows 50% of the breaking power to be returned to the power system. You can see
how this will reduce the overall maneuver energy requirements.
::
show_plots = True, useRwPowerGeneration = True
.. image:: /_images/Scenarios/scenarioAttitudeFeedbackRWPower3True.svg
:align: center
.. image:: /_images/Scenarios/scenarioAttitudeFeedbackRWPower4True.svg
:align: center
"""
#
# Basilisk Scenario Script and Integrated Test
#
# Purpose: Integrated scenario using a RW feedback control law where the RW devices power consumption
# is modeled, as well as the battery drain.
# Author: Hanspeter Schaub
# Creation Date: Jan. 26, 2020
#
import os
import matplotlib.pyplot as plt
import numpy as np
# The path to the location of Basilisk
# Used to get the location of supporting data.
from Basilisk import __path__
from Basilisk.architecture import messaging
from Basilisk.fswAlgorithms import (mrpFeedback, attTrackingError,
inertial3D, rwMotorTorque)
from Basilisk.simulation import ReactionWheelPower
from Basilisk.simulation import reactionWheelStateEffector, simpleNav, spacecraft
from Basilisk.simulation import simpleBattery
from Basilisk.utilities import (SimulationBaseClass, macros,
orbitalMotion, simIncludeGravBody,
simIncludeRW, unitTestSupport, vizSupport)
bskPath = __path__[0]
fileName = os.path.basename(os.path.splitext(__file__)[0])
# Plotting functions
[docs]def plot_attitude_error(timeData, dataSigmaBR):
"""Plot the attitude errors."""
plt.figure(1)
for idx in range(3):
plt.plot(timeData, dataSigmaBR[:, idx],
color=unitTestSupport.getLineColor(idx, 3),
label=r'$\sigma_' + str(idx) + '$')
plt.legend(loc='lower right')
plt.xlabel('Time [min]')
plt.ylabel(r'Attitude Error $\sigma_{B/R}$')
[docs]def plot_rw_motor_torque(timeData, dataUsReq, dataRW, numRW):
"""Plot the RW actual motor torques."""
plt.figure(2)
for idx in range(3):
plt.plot(timeData, dataUsReq[:, idx],
'--',
color=unitTestSupport.getLineColor(idx, numRW),
label=r'$\hat u_{s,' + str(idx) + '}$')
plt.plot(timeData, dataRW[idx],
color=unitTestSupport.getLineColor(idx, numRW),
label='$u_{s,' + str(idx) + '}$')
plt.legend(loc='lower right')
plt.xlabel('Time [min]')
plt.ylabel('RW Motor Torque (Nm)')
[docs]def plot_rw_power(timeData, dataRwPower, numRW):
"""Plot the RW actual motor torques."""
plt.figure(3)
for idx in range(3):
plt.plot(timeData, dataRwPower[idx],
color=unitTestSupport.getLineColor(idx, numRW),
label='$p_{rw,' + str(idx) + '}$')
plt.legend(loc='lower right')
plt.xlabel('Time [min]')
plt.ylabel('RW Power (W)')
[docs]def run(show_plots, useRwPowerGeneration):
"""
The scenarios can be run with the followings setups parameters:
Args:
show_plots (bool): Determines if the script should display plots
useRwPowerGeneration (bool): Specify if the RW power generation ability is being model when breaking
"""
# Create simulation variable names
simTaskName = "simTask"
simProcessName = "simProcess"
# Create a sim module as an empty container
scSim = SimulationBaseClass.SimBaseClass()
# set the simulation time variable used later on
simulationTime = macros.min2nano(10.)
#
# create the simulation process
#
dynProcess = scSim.CreateNewProcess(simProcessName)
# create the dynamics task and specify the integration update time
simulationTimeStep = macros.sec2nano(.1)
dynProcess.addTask(scSim.CreateNewTask(simTaskName, simulationTimeStep))
#
# setup the simulation tasks/objects
#
# initialize spacecraft object and set properties
scObject = spacecraft.Spacecraft()
scObject.ModelTag = "bsk-Sat"
# define the simulation inertia
I = [900., 0., 0.,
0., 800., 0.,
0., 0., 600.]
scObject.hub.mHub = 750.0 # kg - spacecraft mass
scObject.hub.r_BcB_B = [[0.0], [0.0], [0.0]] # m - position vector of body-fixed point B relative to CM
scObject.hub.IHubPntBc_B = unitTestSupport.np2EigenMatrix3d(I)
# add spacecraft object to the simulation process
scSim.AddModelToTask(simTaskName, scObject, 1)
# clear prior gravitational body and SPICE setup definitions
gravFactory = simIncludeGravBody.gravBodyFactory()
# setup Earth Gravity Body
earth = gravFactory.createEarth()
earth.isCentralBody = True # ensure this is the central gravitational body
mu = earth.mu
# attach gravity model to spacecraft
gravFactory.addBodiesTo(scObject)
#
# add RW devices
#
# Make a fresh RW factory instance, this is critical to run multiple times
rwFactory = simIncludeRW.rwFactory()
# store the RW dynamical model type
varRWModel = messaging.BalancedWheels
# create each RW by specifying the RW type, the spin axis gsHat, plus optional arguments
RW1 = rwFactory.create('Honeywell_HR16', [1, 0, 0], maxMomentum=50., Omega=100. # RPM
, RWModel=varRWModel
)
RW2 = rwFactory.create('Honeywell_HR16', [0, 1, 0], maxMomentum=50., Omega=200. # RPM
, RWModel=varRWModel
)
RW3 = rwFactory.create('Honeywell_HR16', [0, 0, 1], maxMomentum=50., Omega=300. # RPM
, rWB_B=[0.5, 0.5, 0.5] # meters
, RWModel=varRWModel
)
rwList = [RW1, RW2, RW3]
numRW = rwFactory.getNumOfDevices()
# create RW object container and tie to spacecraft object
rwStateEffector = reactionWheelStateEffector.ReactionWheelStateEffector()
rwFactory.addToSpacecraft(scObject.ModelTag, rwStateEffector, scObject)
# add RW object array to the simulation process
scSim.AddModelToTask(simTaskName, rwStateEffector, 2)
# add the simple Navigation sensor module. This sets the SC attitude, rate, position
# velocity navigation message
sNavObject = simpleNav.SimpleNav()
sNavObject.ModelTag = "SimpleNavigation"
scSim.AddModelToTask(simTaskName, sNavObject)
sNavObject.scStateInMsg.subscribeTo(scObject.scStateOutMsg)
# add RW power modules
rwPowerList = []
for c in range(numRW):
powerRW = ReactionWheelPower.ReactionWheelPower()
powerRW.ModelTag = scObject.ModelTag + "RWPower" + str(c)
powerRW.basePowerNeed = 5. # baseline power draw, Watts
powerRW.rwStateInMsg.subscribeTo(rwStateEffector.rwOutMsgs[c])
if useRwPowerGeneration:
powerRW.mechToElecEfficiency = 0.5
scSim.AddModelToTask(simTaskName, powerRW)
rwPowerList.append(powerRW)
# create battery module
battery = simpleBattery.SimpleBattery()
battery.ModelTag = scObject.ModelTag
battery.storageCapacity = 300000 # W-s
battery.storedCharge_Init = battery.storageCapacity * 0.8 # 20% depletion
scSim.AddModelToTask(simTaskName, battery)
# connect RW power to the battery module
for c in range(numRW):
battery.addPowerNodeToModel(rwPowerList[c].nodePowerOutMsg)
#
# setup the FSW algorithm tasks
#
# create the FSW vehicle configuration message
vehicleConfigOut = messaging.VehicleConfigMsgPayload()
vehicleConfigOut.ISCPntB_B = I # use the same inertia in the FSW algorithm as in the simulation
vcMsg = messaging.VehicleConfigMsg().write(vehicleConfigOut)
# make the FSW RW configuration message
fswRwMsg = rwFactory.getConfigMessage()
# setup inertial3D guidance module
inertial3DObj = inertial3D.inertial3D()
inertial3DObj.ModelTag = "inertial3D"
scSim.AddModelToTask(simTaskName, inertial3DObj)
inertial3DObj.sigma_R0N = [0., 0., 0.] # set the desired inertial orientation
# setup the attitude tracking error evaluation module
attError = attTrackingError.attTrackingError()
attError.ModelTag = "attErrorInertial3D"
scSim.AddModelToTask(simTaskName, attError)
attError.attRefInMsg.subscribeTo(inertial3DObj.attRefOutMsg)
attError.attNavInMsg.subscribeTo(sNavObject.attOutMsg)
# setup the MRP Feedback control module
mrpControl = mrpFeedback.mrpFeedback()
mrpControl.ModelTag = "mrpFeedback"
scSim.AddModelToTask(simTaskName, mrpControl)
mrpControl.guidInMsg.subscribeTo(attError.attGuidOutMsg)
mrpControl.vehConfigInMsg.subscribeTo(vcMsg)
mrpControl.rwParamsInMsg.subscribeTo(fswRwMsg)
mrpControl.rwSpeedsInMsg.subscribeTo(rwStateEffector.rwSpeedOutMsg)
mrpControl.K = 3.5
mrpControl.Ki = -1 # make value negative to turn off integral feedback
mrpControl.P = 30.0
mrpControl.integralLimit = 2. / mrpControl.Ki * 0.1
# add module that maps the Lr control torque into the RW motor torques
rwMotorTorqueObj = rwMotorTorque.rwMotorTorque()
rwMotorTorqueObj.ModelTag = "rwMotorTorque"
scSim.AddModelToTask(simTaskName, rwMotorTorqueObj)
# Initialize the test module msg names
rwMotorTorqueObj.vehControlInMsg.subscribeTo(mrpControl.cmdTorqueOutMsg)
rwMotorTorqueObj.rwParamsInMsg.subscribeTo(fswRwMsg)
rwStateEffector.rwMotorCmdInMsg.subscribeTo(rwMotorTorqueObj.rwMotorTorqueOutMsg)
# Make the RW control all three body axes
controlAxes_B = [
1, 0, 0, 0, 1, 0, 0, 0, 1
]
rwMotorTorqueObj.controlAxes_B = controlAxes_B
#
# Setup data logging before the simulation is initialized
#
numDataPoints = 100
samplingTime = unitTestSupport.samplingTime(simulationTime, simulationTimeStep, numDataPoints)
rwCmdLog = rwMotorTorqueObj.rwMotorTorqueOutMsg.recorder(samplingTime)
attErrLog = attError.attGuidOutMsg.recorder(samplingTime)
scSim.AddModelToTask(simTaskName, rwCmdLog)
scSim.AddModelToTask(simTaskName, attErrLog)
# To log the RW information, the following code is used:
rwSpeedLog = rwStateEffector.rwSpeedOutMsg.recorder(samplingTime)
scSim.AddModelToTask(simTaskName, rwSpeedLog)
rwOutLog = []
rwPowLog = []
for c in range(numRW):
rwOutLog.append(rwStateEffector.rwOutMsgs[c].recorder(samplingTime))
rwPowLog.append(rwPowerList[c].nodePowerOutMsg.recorder(samplingTime))
scSim.AddModelToTask(simTaskName, rwOutLog[-1])
scSim.AddModelToTask(simTaskName, rwPowLog[-1])
batPowLog = battery.batPowerOutMsg.recorder(samplingTime)
scSim.AddModelToTask(simTaskName, batPowLog)
#
# set initial Spacecraft States
#
# setup the orbit using classical orbit elements
oe = orbitalMotion.ClassicElements()
oe.a = 10000000.0 # meters
oe.e = 0.01
oe.i = 33.3 * macros.D2R
oe.Omega = 48.2 * macros.D2R
oe.omega = 347.8 * macros.D2R
oe.f = 85.3 * macros.D2R
rN, vN = orbitalMotion.elem2rv(mu, oe)
scObject.hub.r_CN_NInit = rN # m - r_CN_N
scObject.hub.v_CN_NInit = vN # m/s - v_CN_N
scObject.hub.sigma_BNInit = [[0.1], [0.2], [-0.3]] # sigma_CN_B
scObject.hub.omega_BN_BInit = [[0.001], [-0.01], [0.03]] # rad/s - omega_CN_B
# if this scenario is to interface with the BSK Viz, uncomment the following lines
viz = vizSupport.enableUnityVisualization(scSim, simTaskName, scObject
# , saveFile=fileName
, rwEffectorList=rwStateEffector
)
#
# initialize Simulation
#
scSim.InitializeSimulation()
#
# configure a simulation stop time and execute the simulation run
#
scSim.ConfigureStopTime(simulationTime)
scSim.ExecuteSimulation()
#
# retrieve the logged data
#
dataUsReq = rwCmdLog.motorTorque[:, range(numRW)]
dataSigmaBR = attErrLog.sigma_BR
dataRW = []
dataRwPower = []
for c in range(0, numRW):
dataRW.append(rwOutLog[c].u_current)
dataRwPower.append(rwPowLog[c].netPower)
batteryStorageLog = batPowLog.storageLevel
np.set_printoptions(precision=16)
#
# plot the results
#
timeData = rwCmdLog.times() * macros.NANO2MIN
plt.close("all") # clears out plots from earlier test runs
figureList = {}
plot_attitude_error(timeData, dataSigmaBR)
plot_rw_motor_torque(timeData, dataUsReq, dataRW, numRW)
plot_rw_power(timeData, dataRwPower, numRW)
pltName = fileName + "3" + str(useRwPowerGeneration)
figureList[pltName] = plt.figure(3)
plt.figure(4)
plt.plot(timeData, batteryStorageLog)
plt.xlabel('Time [min]')
plt.ylabel('Battery Storage (Ws)')
pltName = fileName + "4" + str(useRwPowerGeneration)
figureList[pltName] = plt.figure(4)
if show_plots:
plt.show()
# close the plots being saved off to avoid over-writing old and new figures
plt.close("all")
return figureList
#
# This statement below ensures that the unit test scrip can be run as a
# stand-along python script
#
if __name__ == "__main__":
run(
True, # show_plots
True # useRwPowerGeneration
)