#
# 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,
vizSupport,
)
from Basilisk.utilities import simHelpers
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=simHelpers.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=simHelpers.getLineColor(idx, numRW),
label=r'$\hat u_{s,' + str(idx) + '}$')
plt.plot(timeData, dataRW[idx],
color=simHelpers.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=simHelpers.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 = simHelpers.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
# use the same inertia in the FSW algorithm as in the simulation
vehicleConfigOut = messaging.VehicleConfigMsgPayload(ISCPntB_B=I)
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 = simHelpers.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
)