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WarpTwin
Documentation for WarpTwin models and classes.
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WarpTwin
Documentation for WarpTwin models and classes.
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""" =====================================================
! FIRST READ CustomSpacecraft.py
he following python script is designed to perform an
energy budget analysis of your mission to help
inform power based design decisions. This script will
run a monte carlo analysis with a provided power configuration,
and inform the team if the configuration works.
In this simulation, it is assumed that the power draw of all
the components running in a given mission mode has already been
determined. At every time step, the power draw is perturbed by
a percentage the follows a Gaussian distribution with determined
mean and standard deviation.
This script accounts for eclipse zones and the fact that the
spacecraft will eclipse itself. We also model each mission mode
accurately (though under ideal conditions). There is a tumble in
safe mode and we are perfectly nadir pointing in nominal and
experiment mode. This script also accounts for the power induced
by downlinking. The script accurately models a ground station with
a 10 degree elevation mask and will start a downlink every time
the ground station is not masked.
! To actually run this script see custom_deliverables_bash.sh
Author James Tabony <james.tabony@attx.tech> : 10/31/25
===================================================== """
import sys, os, argparse
from warptwin.WarpTwinPy import (SimulationExecutive, LOG_INFO, CsvLogger, DEGREES_TO_RADIANS, CartesianVector3, Time, connectSignals)
from warptwin.BiasNoiseModel import BiasNoiseModel
from warptwin.TwoAxisPointingGuidance import TwoAxisPointingGuidance
from CustomSpacecraft import CustomSpacecraft
from configs import (disperseDate, disperseOrbitParams)
#########################################################
# System Parameters
#########################################################
# Define the total power draws in each mission mode
# These values are gathered externally through data sheets and testing
POWER_DRAW_SAFE = 4.69 # Average power draw in safe mode [W]
POWER_DRAW_NOMINAL = 5.82 # Average power draw in nominal mode [W]
POWER_DRAW_EXPERIMENT = 11.52 # Average power draw in experiment mode [W]
POWER_DRAW_FROM_TRANSMIT = 9 # Average power draw induced by transmitting [W]
POWER_DRAW_PERTURBATION = 0.02 # Standard deviation to instantaneous power draw [%] - 2%
# Define the date dispersions
START_YEAR = 2028
START_MONTH_RANGE = [1, 12]
# Define the orbit element dispersions
ALTITUDE_RANGE = [400.0*1000.0, 500.0*1000.0] # [meters]
INCLINATION_RANGE = [45.0, 85.0] # [degrees]
# Define simulation duration
SIM_DURATION = 48*3600 # [seconds]
# Define component configuration
SOLAR_PANEL_NAME = "EnduroSat"
BATTERY_NAME = "GOMspace_nanopower_bp4_2s2p"
# Define uniform dispersions of battery initial charge
BATTERY_RANGE = [1.0, 0.7, 1.0] # Nominal, Minimum, Maximum [%]
#########################################################
# Setup Simulation
#########################################################
if __name__ == '__main__':
# Set up the simulation executive
exc = SimulationExecutive() # Create a simulation executive
exc.args().addDefaultArgument("end", SIM_DURATION) # Set simulated end time to desired duration
exc.parseArgs(sys.argv) # Parse terminal line inputs
exc.setRateHz(1) # Set simulation rate to 1 Hz
exc.logLevel(LOG_INFO) # Set the Log level to none to receive more simulation information
# Set the start time based on a dispersed date
date_str = disperseDate(exc, START_YEAR, START_MONTH_RANGE)
exc.setTime(date_str)
# Gather the case from an argument parser
parser = argparse.ArgumentParser()
parser.add_argument("--case", type=str, default="safe")
parser.add_argument("--run", type=int, required=False)
parser.add_argument("--out-dir", type=str, required=False)
args = parser.parse_args()
case = args.case
# Configure simulation based on mission mode
match case:
case 'safe':
base_power_draw = POWER_DRAW_SAFE
allow_downlink = False
nadir_point = False
case 'nominal':
base_power_draw = POWER_DRAW_NOMINAL
allow_downlink = True
nadir_point = True
case 'experiment':
base_power_draw = POWER_DRAW_EXPERIMENT
allow_downlink = True
nadir_point = True
case _:
raise TypeError(f"Case {case} not valid")
# Create an instance of the CustomSpacecraft class
sc = CustomSpacecraft(exc)
if allow_downlink:
# Add ground station at ATTX site
idx = sc.configGroundStation()
# Set elevation mask to 10 degrees
sc.ground_stations[idx].params.elevation_mask_rad(10.0*DEGREES_TO_RADIANS)
# Disperse the initial battery charge
battery_charge = sc._exc.dispersions().createUniformInputDispersion("initial_battery",
BATTERY_RANGE[0],
BATTERY_RANGE[1],
BATTERY_RANGE[2])
battery_charge = battery_charge()()
# Configure the Solar Panels
sc.configSolarPanelFromJson(SOLAR_PANEL_NAME)
# Configure the Battery
sc.configBatteryFromJson(BATTERY_NAME, battery_charge)
# Create a bias noise model to purturb the power draw
noise = BiasNoiseModel(sc._exc)
# Set the standard deviation to determined value
noise.params.noise_std(POWER_DRAW_PERTURBATION)
if nadir_point:
# Create a two axis pointing guidance algorithm
guidance = TwoAxisPointingGuidance(sc._exc)
guidance.inputs.current_primary_body(CartesianVector3([1.0, 0.0, 0.0])) # X-axis points nadir
guidance.inputs.current_secondary_body(CartesianVector3([0.0, 0.0, 1.0])) # Z-axis points towards sun
connectSignals(sc.nadir_pointing_sensor.outputs.pos_tgt_ref__out, guidance.inputs.desired_primary)
connectSignals(sc.sun_pointing_sensor.outputs.pos_tgt_ref__out, guidance.inputs.desired_secondary)
# Create Logger
logger = CsvLogger(sc._exc, "states.csv") # Create an instance of the logger and configure the file name
logger.addParameter(sc._exc.time().base_time, "time") # Save simulation time [sec]
logger.addParameter(sc.battery.outputs.system_voltage, "voltage") # Save the voltage stored in the battery [V]
logger.addParameter(sc.battery.outputs.power_available, "power_available") # Save the boolean denoting a battery SOH fault [0 true, 1 false]
logger.addParameter(sc.battery.inputs.power_generation_in, "power_in") # Save the power entering the battery [W]
logger.addParameter(sc.battery.inputs.power_draw_out, "power_out") # Save the power leaving the battery [W]
exc.logManager().addLog(logger, Time(10)) # Add the logger to the simulation executive log manager and save data at 10 seconds
# Startup simulation
exc.startup()
# Initialize the position and velocity of CustomSpacecraft using dispersed orbit elements
elements = disperseOrbitParams(sc._exc, ALTITUDE_RANGE, INCLINATION_RANGE)
sc.initializeState(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5])
# Initialize an arbitrary tumble
sc.body().ang_vel_f_p__f(CartesianVector3([0.001, 0.002, 0.003]))
# Run the simulation
exc.step(Time(0))
while not exc.isTerminated():
# Compute the total power generated from each solar panel
total_power_generated = 0
for i in range(len(sc.panels)):
total_power_generated += sc.panels[i].outputs.power()
# Pass the power generated to the battery model
sc.battery.inputs.power_generation_in(total_power_generated)
# Check if downlink is possible and determine power draw
if (allow_downlink and not sc.ground_stations[idx].outputs.masked()):
power_draw = base_power_draw + POWER_DRAW_FROM_TRANSMIT
else:
power_draw = base_power_draw
# Pass the power draw to the battery model
sc.battery.inputs.power_draw_out(power_draw * (1.0+noise.outputs.output_val()))
# Check if nadir pointing is active and determine attitude
if nadir_point:
sc.body().rootRelQuaternion(guidance.outputs.quat_body_ref())
# Step simulation
exc.step()
1.16.1