#
# 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
--------
This script duplicates the basic orbit simulation in the scenario :ref:`scenarioBasicOrbit`.
The difference is that this version allows for the Basilisk simulation data to be live streamed to the
:ref:`vizard` visualization program.
The script is found in the folder ``src/examples`` and executed by using::
python3 scenarioBasicOrbitStream.py
To enable live data streaming, the ``enableUnityVisualization()`` method is provided with ``liveStream``
argument using::
vizSupport.enableUnityVisualization(scSim, simTaskName, simProcessName, gravBodies=gravFactory,
liveStream=True)
When starting Basilisk simulation it prints now to the terminal that it is trying to connect to Vizard::
Waiting for Vizard at tcp://localhost:5556
Copy ``tcp://localhost:5556`` and open the Vizard application. Enter this address in the connection field and select
"Direct Communication" mode as well as "Live Streaming". After this the Basilisk simulation resumes and
will live stream the data to Vizard.
.. figure:: /_images/static/vizard-ImgStream.jpg
:align: center
:scale: 50 %
Vizard Direct Communication Panel Illustration
To avoid the simulation running too quickly, this tutorial example script includes the ``clock_sync`` module that
enables a 50x realtime mode using::
clockSync = clock_synch.ClockSynch()
clockSync.accelFactor = 50.0
scSim.AddModelToTask(simTaskName, clockSync)
This way a 10s simulation time step will take 0.2 seconds with the 50x speed up factor.
"""
#
# Basilisk Scenario Script and Integrated Test
#
# Purpose: Integrated test of the spacecraftPlus() and gravity modules. Illustrates
# a 3-DOV spacecraft on a range of orbit types with live Vizard data streaming.
# Author: Hanspeter Schaub
# Creation Date: Sept. 29, 2019
#
import os
import numpy as np
import matplotlib.pyplot as plt
# The path to the location of Basilisk
# Used to get the location of supporting data.
from Basilisk import __path__
bskPath = __path__[0]
fileName = os.path.basename(os.path.splitext(__file__)[0])
# import simulation related support
from Basilisk.simulation import spacecraftPlus
# general support file with common unit test functions
# import general simulation support files
from Basilisk.utilities import (SimulationBaseClass, macros, orbitalMotion,
simIncludeGravBody, unitTestSupport, vizSupport)
from Basilisk.simulation import clock_synch
[docs]def run(show_plots, liveStream, timeStep, orbitCase, useSphericalHarmonics, planetCase):
"""
At the end of the python script you can specify the following example parameters.
Args:
show_plots (bool): Determines if the script should display plots
livePlots (bool): Determines if the script should use live plotting
orbitCase (str):
====== ============================
String Definition
====== ============================
'LEO' Low Earth Orbit
'GEO' Geosynchronous Orbit
'GTO' Geostationary Transfer Orbit
====== ============================
useSphericalHarmonics (Bool): False to use first order gravity approximation: :math:`\\frac{GMm}{r^2}`
planetCase (str): {'Earth', 'Mars'}
"""
# Create simulation variable names
simTaskName = "simTask"
simProcessName = "simProcess"
# Create a sim module as an empty container
scSim = SimulationBaseClass.SimBaseClass()
#
# create the simulation process
#
dynProcess = scSim.CreateNewProcess(simProcessName)
# create the dynamics task and specify the integration update time
simulationTimeStep = macros.sec2nano(timeStep)
dynProcess.addTask(scSim.CreateNewTask(simTaskName, simulationTimeStep))
#
# setup the simulation tasks/objects
#
# initialize spacecraftPlus object and set properties
scObject = spacecraftPlus.SpacecraftPlus()
scObject.ModelTag = "spacecraftBody"
# add spacecraftPlus object to the simulation process
scSim.AddModelToTask(simTaskName, scObject)
# setup Gravity Body
gravFactory = simIncludeGravBody.gravBodyFactory()
if planetCase is 'Mars':
planet = gravFactory.createMarsBarycenter()
planet.isCentralBody = True # ensure this is the central gravitational body
if useSphericalHarmonics:
planet.useSphericalHarmParams = True
simIncludeGravBody.loadGravFromFile(bskPath + '/supportData/LocalGravData/GGM2BData.txt',
planet.spherHarm, 100)
else: # Earth
planet = gravFactory.createEarth()
planet.isCentralBody = True # ensure this is the central gravitational body
if useSphericalHarmonics:
planet.useSphericalHarmParams = True
simIncludeGravBody.loadGravFromFile(bskPath + '/supportData/LocalGravData/GGM03S-J2-only.txt',
planet.spherHarm, 2)
mu = planet.mu
# attach gravity model to spaceCraftPlus
scObject.gravField.gravBodies = spacecraftPlus.GravBodyVector(list(gravFactory.gravBodies.values()))
#
# setup orbit and simulation time
#
# setup the orbit using classical orbit elements
oe = orbitalMotion.ClassicElements()
rLEO = 7000. * 1000 # meters
rGEO = 42000. * 1000 # meters
if orbitCase is 'GEO':
oe.a = rGEO
oe.e = 0.00001
oe.i = 0.0 * macros.D2R
elif orbitCase is 'GTO':
oe.a = (rLEO + rGEO) / 2.0
oe.e = 1.0 - rLEO / oe.a
oe.i = 0.0 * macros.D2R
else: # LEO case, default case 0
oe.a = rLEO
oe.e = 0.0001
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)
oe = orbitalMotion.rv2elem(mu, rN, vN) # this stores consistent initial orbit elements
# with circular or equatorial orbit, some angles are arbitrary
#
# initialize Spacecraft States with the initialization variables
#
scObject.hub.r_CN_NInit = unitTestSupport.np2EigenVectorXd(rN) # m - r_BN_N
scObject.hub.v_CN_NInit = unitTestSupport.np2EigenVectorXd(vN) # m/s - v_BN_N
# set the simulation time
n = np.sqrt(mu / oe.a / oe.a / oe.a)
P = 2. * np.pi / n
if useSphericalHarmonics:
simulationTime = macros.sec2nano(3. * P)
else:
simulationTime = macros.sec2nano(0.75 * P)
#
# Setup data logging before the simulation is initialized
#
if useSphericalHarmonics:
numDataPoints = 400
else:
numDataPoints = 100
samplingTime = simulationTime // (numDataPoints - 1)
scSim.TotalSim.logThisMessage(scObject.scStateOutMsgName, samplingTime)
if liveStream:
clockSync = clock_synch.ClockSynch()
clockSync.accelFactor = 50.0
scSim.AddModelToTask(simTaskName, clockSync)
# if this scenario is to interface with the BSK Viz, uncomment the following line
vizSupport.enableUnityVisualization(scSim, simTaskName, simProcessName, gravBodies=gravFactory,
liveStream=True)
#
# initialize Simulation: This function clears the simulation log, and runs the self_init()
# cross_init() and reset() routines on each module.
# If the routine InitializeSimulationAndDiscover() is run instead of InitializeSimulation(),
# then the all messages are auto-discovered that are shared across different BSK threads.
#
scSim.InitializeSimulationAndDiscover()
#
# configure a simulation stop time time and execute the simulation run
#
scSim.ConfigureStopTime(simulationTime)
scSim.ExecuteSimulation()
#
# retrieve the logged data
#
posData = scSim.pullMessageLogData(scObject.scStateOutMsgName + '.r_BN_N', list(range(3)))
velData = scSim.pullMessageLogData(scObject.scStateOutMsgName + '.v_BN_N', list(range(3)))
np.set_printoptions(precision=16)
#
# plot the results
#
# draw the inertial position vector components
plt.close("all") # clears out plots from earlier test runs
plt.figure(1)
fig = plt.gcf()
ax = fig.gca()
ax.ticklabel_format(useOffset=False, style='plain')
for idx in range(1, 4):
plt.plot(posData[:, 0] * macros.NANO2SEC / P, posData[:, idx] / 1000.,
color=unitTestSupport.getLineColor(idx, 3),
label='$r_{BN,' + str(idx) + '}$')
plt.legend(loc='lower right')
plt.xlabel('Time [orbits]')
plt.ylabel('Inertial Position [km]')
figureList = {}
pltName = fileName + "1" + orbitCase + str(int(useSphericalHarmonics))+ planetCase
figureList[pltName] = plt.figure(1)
if useSphericalHarmonics is False:
# draw orbit in perifocal frame
b = oe.a * np.sqrt(1 - oe.e * oe.e)
p = oe.a * (1 - oe.e * oe.e)
plt.figure(2, figsize=np.array((1.0, b / oe.a)) * 4.75, dpi=100)
plt.axis(np.array([-oe.rApoap, oe.rPeriap, -b, b]) / 1000 * 1.25)
# draw the planet
fig = plt.gcf()
ax = fig.gca()
if planetCase == 'Mars':
planetColor = '#884400'
else:
planetColor = '#008800'
planetRadius = planet.radEquator / 1000
ax.add_artist(plt.Circle((0, 0), planetRadius, color=planetColor))
# draw the actual orbit
rData = []
fData = []
for idx in range(0, len(posData)):
oeData = orbitalMotion.rv2elem(mu, posData[idx, 1:4], velData[idx, 1:4])
rData.append(oeData.rmag)
fData.append(oeData.f + oeData.omega - oe.omega)
plt.plot(rData * np.cos(fData) / 1000, rData * np.sin(fData) / 1000, color='#aa0000', linewidth=3.0
)
# draw the full osculating orbit from the initial conditions
fData = np.linspace(0, 2 * np.pi, 100)
rData = []
for idx in range(0, len(fData)):
rData.append(p / (1 + oe.e * np.cos(fData[idx])))
plt.plot(rData * np.cos(fData) / 1000, rData * np.sin(fData) / 1000, '--', color='#555555'
)
plt.xlabel('$i_e$ Cord. [km]')
plt.ylabel('$i_p$ Cord. [km]')
plt.grid()
else:
plt.figure(2)
fig = plt.gcf()
ax = fig.gca()
ax.ticklabel_format(useOffset=False, style='plain')
smaData = []
for idx in range(0, len(posData)):
oeData = orbitalMotion.rv2elem(mu, posData[idx, 1:4], velData[idx, 1:4])
smaData.append(oeData.a / 1000.)
plt.plot(posData[:, 0] * macros.NANO2SEC / P, smaData, color='#aa0000',
)
plt.xlabel('Time [orbits]')
plt.ylabel('SMA [km]')
pltName = fileName + "2" + orbitCase + str(int(useSphericalHarmonics)) + planetCase
figureList[pltName] = plt.figure(2)
if show_plots:
plt.show()
# close the plots being saved off to avoid over-writing old and new figures
plt.close("all")
return posData, figureList
#
# This statement below ensures that the unit test scrip can be run as a
# stand-along python script
#
if __name__ == "__main__":
run(
False, # show_plots
True, # liveStream
1.0, # time step (s)
'LEO', # orbit Case (LEO, GTO, GEO)
False, # useSphericalHarmonics
'Earth' # planetCase (Earth, Mars)
)