Merge pull request AVSLab#606 from AVSLab/feature/halo

New halo example script

Author: schaubh

docs/source/Support/bskReleaseNotes.rst

@@ -36,7 +36,8 @@ Version |release|
 - Fixed a bug where the legacy variable logging API would either, not log at all or log at a rate different to the
  requested rate.
 - Fixed a python version checking bug that prevented Basilisk from compiling on Windows
-- Updated versioning to better follow the `semantic versioning <https://semver.org>`_ standard, in the format 
+- Created a new example scenario :ref:`scenarioHaloOrbit` demonstrating a near-Halo orbit simulation
+- Updated versioning to better follow the `semantic versioning <https://semver.org>`_ standard, in the format
  ``MAJOR.MINOR.PATCH``. Releases will increment the minor version number, while pull requests into develop will 
  automatically increment the patch number. This allows users to reference/require specific versions of Basilisk 
  outside of the release cycle.

examples/_default.rst

@@ -33,6 +33,7 @@ Orbital Simulations
  Simulating Trajectory about Multiple Celestial Bodies <scenarioPatchedConics>
  Including Custom Gravitational Bodies <scenarioCustomGravBody>
  Small Body Waypoint-to-Waypoint Control <scenarioSmallBodyFeedbackControl>
+ Near-Halo Orbit Simulation <scenarioHaloOrbit>
 
 
 Attitude Simulations

examples/scenarioHaloOrbit.py

@@ -0,0 +1,320 @@
+
+# ISC License
+#
+# Copyright (c) 2024, 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 sets up a 3-DOF spacecraft that is operating near-Halo orbit at L2 Earth-Moon Lagrange points. The purpose
+is to illustrate how to set up the spacecraft's initial conditions to create a near-Halo orbit and convert the barycenter focused
+non-dimensional ICs to earth-centered inertial frame components.
+
+The script is found in the folder ``basilisk/examples`` and executed by using::
+
+ python3 scenarioHaloOrbit.py
+
+For this simulation, the Earth is assumed stationary, and the Moon's trajectory is generated using SPICE. Refer to
+:ref:`scenarioOrbitMultiBody` to learn how to create multiple gravity bodies and read a SPICE trajectory.
+
+When the simulation completes, three plots are shown. The first plot shows the orbits of the Moon and spacecraft in
+the Earth-centered inertial frame. The second and third plots show the motion of the spacecraft in a frame rotating
+with the Moon. In the second plot, the y-axis represents the Moon's velocity direction, and in the third plot, the
+y-axis represents the cross product of the Moon's position vector and velocity vector.
+
+Illustration of Simulation Results
+----------------------------------
+
+The following images illustrate the simulation run results with the following settings:
+
+::
+
+ showPlots = True
+
+.. image:: /_images/Scenarios/scenarioHaloOrbitFig1.svg
+ :align: center
+
+.. image:: /_images/Scenarios/scenarioHaloOrbitFig2.svg
+ :align: center
+
+.. image:: /_images/Scenarios/scenarioHaloOrbitFig3.svg
+ :align: center
+
+
+"""
+
+#
+# Basilisk Scenario Script and Integrated Test
+#
+# Purpose: This scenario illustrates the near-Halo orbit of a spacecraft.
+# Author: Yumeka Nagano
+# Creation Date: Feb. 12, 2024
+#
+
+import os
+from datetime import datetime
+
+import matplotlib.pyplot as plt
+import numpy as np
+from Basilisk import __path__
+from Basilisk.simulation import spacecraft
+from Basilisk.topLevelModules import pyswice
+from Basilisk.utilities import (SimulationBaseClass, macros, orbitalMotion,
+ simIncludeGravBody, unitTestSupport, vizSupport)
+from Basilisk.utilities.pyswice_spk_utilities import spkRead
+
+bskPath = __path__[0]
+fileName = os.path.basename(os.path.splitext(__file__)[0])
+
+def run(showPlots=True):
+ """
+ Args:
+ showPlots (bool): Determines if the script should display plots
+ """
+
+ # Create simulation variable names
+ simTaskName = "dynTask"
+ simProcessName = "dynProcess"
+
+ # Create a sim module as an empty container
+ scSim = SimulationBaseClass.SimBaseClass()
+ scSim.SetProgressBar(True)
+
+ # Create the simulation process (dynamics)
+ dynProcess = scSim.CreateNewProcess(simProcessName)
+
+ # Add the dynamics task to the dynamics process and specify the integration update time
+ timestep = 300
+ simulationTimeStep = macros.sec2nano(timestep)
+ dynProcess.addTask(scSim.CreateNewTask(simTaskName, simulationTimeStep))
+
+ # Setup the spacecraft object
+ scObject = spacecraft.Spacecraft()
+ scObject.ModelTag = "HaloSat"
+
+ # Add spacecraft object to the simulation process
+ # Make this model a lower priority than the SPICE object task
+ scSim.AddModelToTask(simTaskName, scObject, 0)
+
+ # Setup gravity factory and gravity bodies
+ # Include bodies as a list of SPICE names
+ gravFactory = simIncludeGravBody.gravBodyFactory()
+ gravBodies = gravFactory.createBodies('moon', 'earth')
+ gravBodies['earth'].isCentralBody = True
+
+ # Add gravity bodies to the spacecraft dynamics
+ gravFactory.addBodiesTo(scObject)
+
+ # Create default SPICE module, specify start date/time.
+ timeInitString = "2022 August 31 15:00:00.0"
+ bsk_path = __path__[0]
+ spiceObject = gravFactory.createSpiceInterface(bsk_path + "/supportData/EphemerisData/", time=timeInitString,
+ epochInMsg=True)
+ spiceObject.zeroBase = 'earth'
+
+ # Add SPICE object to the simulation task list
+ scSim.AddModelToTask(simTaskName, spiceObject, 1)
+
+ # Import SPICE ephemeris data into the python environment
+ pyswice.furnsh_c(spiceObject.SPICEDataPath + 'de430.bsp') # solar system bodies
+ pyswice.furnsh_c(spiceObject.SPICEDataPath + 'naif0012.tls') # leap second file
+ pyswice.furnsh_c(spiceObject.SPICEDataPath + 'de-403-masses.tpc') # solar system masses
+ pyswice.furnsh_c(spiceObject.SPICEDataPath + 'pck00010.tpc') # generic Planetary Constants Kernel
+
+ # Set spacecraft ICs
+ # Get initial moon data
+ moonSpiceName = 'moon'
+ moonInitialState = 1000 * spkRead(moonSpiceName, timeInitString, 'J2000', 'earth')
+ moon_rN_init = moonInitialState[0:3]
+ moon_vN_init = moonInitialState[3:6]
+ moon = gravBodies['moon']
+ earth = gravBodies['earth']
+ oe = orbitalMotion.rv2elem(earth.mu, moon_rN_init, moon_vN_init)
+ moon_a = oe.a
+
+ # Direction Cosine Matrix (DCM) from earth centered inertial frame to earth-moon rotation frame
+ DCMInit = np.array([moon_rN_init/np.linalg.norm(moon_rN_init),moon_vN_init/np.linalg.norm(moon_vN_init),
+ np.cross(moon_rN_init, moon_vN_init) / np.linalg.norm(np.cross(moon_rN_init, moon_vN_init))])
+
+ # Set up non-dimensional parameters
+ T_ND = np.sqrt(moon_a ** 3 / (earth.mu + moon.mu)) # non-dimensional time for one second
+ mu_ND = moon.mu/(earth.mu + moon.mu) # non-dimensional mass
+
+ # Set up initial conditions for the spacecraft
+ x0 = 1.182212 * moon_a + moon_a * mu_ND
+ z0 = 0.049 * moon_a
+ dy0 = -0.167 * moon_a / T_ND
+ X0 = np.array([[x0], [0], [z0]])
+ dX0 = np.array([[0], [np.linalg.norm(moon_vN_init) + dy0], [0]])
+
+ rN = np.dot(np.transpose(DCMInit), X0)
+ vN = np.dot(np.transpose(DCMInit), dX0)
+
+ scObject.hub.r_CN_NInit = rN
+ scObject.hub.v_CN_NInit = vN
+
+ # Set simulation time
+ simulationTime = macros.day2nano(17.5)
+
+ # Setup data logging
+ numDataPoints = 1000
+ samplingTime = unitTestSupport.samplingTime(simulationTime, simulationTimeStep, numDataPoints)
+
+ # Setup spacecraft data recorder
+ scDataRec = scObject.scStateOutMsg.recorder(samplingTime)
+ MoonDataRec = spiceObject.planetStateOutMsgs[0].recorder(samplingTime)
+ scSim.AddModelToTask(simTaskName, scDataRec)
+ scSim.AddModelToTask(simTaskName, MoonDataRec)
+
+ viz = vizSupport.enableUnityVisualization(scSim, simTaskName, scObject,
+ # saveFile=__file__
+ )
+ # Initialize simulation
+ scSim.InitializeSimulation()
+
+ # Execute simulation
+ scSim.ConfigureStopTime(simulationTime)
+ scSim.ExecuteSimulation()
+
+ # Retrieve logged data
+ posData = scDataRec.r_BN_N
+ velData = scDataRec.v_BN_N
+ timeData = scDataRec.times()
+ moonPos = MoonDataRec.PositionVector
+ moonVel = MoonDataRec.VelocityVector
+
+ # Plot results
+ np.set_printoptions(precision=16)
+ plt.close("all")
+ figureList = {}
+ b = oe.a * np.sqrt(1 - oe.e * oe.e)
+
+ # First plot: Draw orbit in inertial frame
+ fig = plt.figure(1, 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)
+ ax = fig.gca()
+ ax.ticklabel_format(style='scientific', scilimits=[-5, 3])
+
+ # Draw 'cartoon' Earth
+ ax.add_artist(plt.Circle((0, 0), 0.2e5, color='b'))
+
+ # Plot spacecraft orbit data
+ rDataSpacecraft = []
+ fDataSpacecraft = []
+ for ii in range(len(posData)):
+ oeDataSpacecraft = orbitalMotion.rv2elem(earth.mu, posData[ii], velData[ii])
+ rDataSpacecraft.append(oeDataSpacecraft.rmag)
+ fDataSpacecraft.append(oeDataSpacecraft.f + oeDataSpacecraft.omega - oe.omega)
+ plt.plot(rDataSpacecraft * np.cos(fDataSpacecraft) / 1000, rDataSpacecraft * np.sin(fDataSpacecraft) / 1000,
+ color='g', linewidth=3.0, label='Spacecraft')
+
+ # Plot moon orbit data
+ rDataMoon = []
+ fDataMoon = []
+ for ii in range(len(timeData)):
+ oeDataMoon = orbitalMotion.rv2elem(earth.mu, moonPos[ii], moonVel[ii])
+ rDataMoon.append(oeDataMoon.rmag)
+ fDataMoon.append(oeDataMoon.f + oeDataMoon.omega - oe.omega)
+ plt.plot(rDataMoon * np.cos(fDataMoon) / 1000, rDataMoon * np.sin(fDataMoon) / 1000, color='0.5',
+ linewidth=3.0, label='Moon')
+
+ plt.xlabel(r'$i_e$ Coord. [km]')
+ plt.ylabel(r'$i_p$ Coord. [km]')
+ plt.grid()
+ plt.legend()
+ pltName = fileName + "Fig1"
+ figureList[pltName] = plt.figure(1)
+
+ # Second plot: Draw orbit in frame rotating with the Moon (the center is L2 point)
+ # x axis is moon position vector direction and y axis is moon velocity vector direction
+ fig = plt.figure(2, figsize=np.array((1.0, b / oe.a)) * 4.75, dpi=100)
+ plt.axis(np.array([-1e5, 5e5, -3e5, 3e5]) * 1.25)
+ ax = fig.gca()
+ ax.ticklabel_format(style='scientific', scilimits=[-5, 3])
+
+ # Draw 'cartoon' Earth
+ ax.add_artist(plt.Circle((0, 0), 0.2e5, color='b'))
+
+ # Plot spacecraft orbit data
+ rSpacecraft = np.zeros((len(posData), 3))
+
+ for ii in range(len(posData)):
+ # Get Moon position and velocity
+ moon_rN = moonPos[ii]
+ moon_vN = moonVel[ii]
+
+ # Direction Cosine Matrix (DCM) from earth centered inertial frame to earth-moon rotation frame
+ rSpacecraftMag = np.linalg.norm(posData[ii])
+ rMoonMag = np.linalg.norm(moon_rN)
+ DCM = [moon_rN / rMoonMag, moon_vN / np.linalg.norm(moon_vN),
+ np.cross(moon_rN, moon_vN) / np.linalg.norm(np.cross(moon_rN, moon_vN))]
+
+ # Spacecraft position in rotating frame
+ rSpacecraft[ii,:] = np.dot(DCM, posData[ii])
+
+ plt.plot(rSpacecraft[:,0] / 1000, rSpacecraft[:,1] / 1000,
+ color='g', linewidth=3.0, label='Spacecraft')
+
+ plt.xlabel('Earth-Moon axis [km]')
+ plt.ylabel('Moon Velocity axis [km]')
+ plt.grid()
+ plt.legend()
+ pltName = fileName + "Fig2"
+ figureList[pltName] = plt.figure(2)
+
+ # Third plot: Draw orbit in frame rotating with the Moon (the center is L2 point)
+ # x axis is moon position vector direction and y axis is the cross product direction of the moon position vector and
+ # velocity vector
+ fig = plt.figure(3, figsize=np.array((1.0, b / oe.a)) * 4.75, dpi=100)
+ plt.axis(np.array([-1e5, 5e5, -3e5, 3e5]) * 1.25)
+ ax = fig.gca()
+ ax.ticklabel_format(style='scientific', scilimits=[-5, 3])
+
+ # Draw 'cartoon' Earth
+ ax.add_artist(plt.Circle((0, 0), 0.2e5, color='b'))
+
+ plt.plot(rSpacecraft[:, 0] / 1000, rSpacecraft[:, 2] / 1000,
+ color='g', linewidth=3.0, label='Spacecraft')
+
+ plt.xlabel('Earth-Moon axis [km]')
+ plt.ylabel('Earth-Moon perpendicular axis [km]')
+ plt.grid()
+ plt.legend()
+ pltName = fileName + "Fig3"
+ figureList[pltName] = plt.figure(3)
+
+ if showPlots:
+ plt.show()
+
+ plt.close("all")
+
+ # Unload spice libraries
+ gravFactory.unloadSpiceKernels()
+ pyswice.unload_c(spiceObject.SPICEDataPath + 'de430.bsp') # solar system bodies
+ pyswice.unload_c(spiceObject.SPICEDataPath + 'naif0012.tls') # leap second file
+ pyswice.unload_c(spiceObject.SPICEDataPath + 'de-403-masses.tpc') # solar system masses
+ pyswice.unload_c(spiceObject.SPICEDataPath + 'pck00010.tpc') # generic Planetary Constants Kernel
+
+ return figureList
+
+
+if __name__ == "__main__":
+ run(
+ True # Show plots
+ )
+
+

src/tests/test_scenarioTest.py

@@ -64,6 +64,7 @@
  , 'scenarioTwoChargedSC'
  , 'scenarioRendezVous'
  , 'scenarioSensorThermal'
+ , 'scenarioHaloOrbit'
  ])
 @pytest.mark.scenarioTest
 def test_scenarioBskScenarios(show_plots, scenarioCase):