def _createStages(self):
''' Initialize each of the stages and all of their subcomponents. '''
stageDicts = self._getStageSubDicts()
# If we're initializing a dropped stage, figure out which one
if self.stage != None:
stageNumbers = []
stageNumberSet = set()
for stageDict in stageDicts:
stageNumber = self.rocketDictReader.getFloat(stageDict + ".stageNumber")
stageNumbers.append(stageNumber)
stageNumberSet.add(stageNumber)
if len(stageNumbers) != len(stageNumberSet):
raise ValueError("For multi-stage rockets, each stage must have a unique stage number. Set the Rocket.StageName.stageNumber value for each stage. 0 for first stage, 1 for second, etc...")
stageNumbers.sort()
stageToInitialize = stageNumbers[self.stage]
# Initialize Stage(s)
initializingAllStages = (self.stage == None)
for stageDictionary in stageDicts:
stageDictReader = SubDictReader(stageDictionary, self.simDefinition)
stageNumber = stageDictReader.getFloat("stageNumber")
if initializingAllStages or stageNumber == stageToInitialize:
newStage = Stage(stageDictReader, self)
self.stages.append(newStage)
if newStage.name not in self.__dict__: # Avoid clobbering existing info
setattr(self, newStage.name, newStage) # Make stage available as rocket.stageName
def integratorFactory(integrationMethod="Euler", simDefinition=None, discardedTimeStepCallback=None):
'''
Returns a callable integrator object
Inputs:
* integrationMethod: (str) Name of integration method: Examples = "Euler", "RK4", "RK23Adaptive", and "RK45Adaptive"
* simDefinition: (`MAPLEAF.IO.SimDefinition`) for adaptive integration, provide a simdefinition file with time step adaptation parameters
* discardedTimeStepCallback: (1-argument function reference) for adaptive integration, this function (if provided) is called when a time step is computed,
but then discarded and re-computed with a smaller timestep to remain below the max estimated error threshold. Used by MAPLEAF to remove
force calculation logs from those discarded time steps
'''
if "Adapt" in integrationMethod:
if simDefinition == None:
raise ValueError("SimDefinition object required to initialize adaptive integrator")
from MAPLEAF.IO import SubDictReader
adaptDictReader = SubDictReader("SimControl.TimeStepAdaptation", simDefinition)
# Adaptive Integration
controller = adaptDictReader.getString("controller")
if controller == "PID":
PIDCoeffs = [ float(x) for x in adaptDictReader.getString("PID.coefficients").split() ]
safetyFactor = None
elif controller == "elementary":
safetyFactor = adaptDictReader.getFloat("Elementary.safetyFactor")
PIDCoeffs = None
targetError = adaptDictReader.getFloat("targetError")
minFactor = adaptDictReader.getFloat("minFactor")
maxFactor = adaptDictReader.getFloat("maxFactor")
maxTimeStep = adaptDictReader.getFloat("maxTimeStep")
minTimeStep = adaptDictReader.getFloat("minTimeStep")
return AdaptiveIntegrator(
method=integrationMethod,
controller=controller,
targetError=targetError,
maxMinSafetyFactors=[maxFactor, minFactor, safetyFactor],
PIDCoeffs=PIDCoeffs,
maxTimeStep=maxTimeStep,
minTimeStep=minTimeStep,
discardedTimeStepCallback=discardedTimeStepCallback
)
else:
# Constant time step integrator
return ClassicalIntegrator(method=integrationMethod)
def __init__(self, simDefinition=None, silent=False):
''' Sets up the Wind, Atmospheric, and Earth models requested in the Sim Definition file '''
self.launchRail = None
if simDefinition != None:
# Whenever we're running a real simulation, should always end up here
envDictReader = SubDictReader("Environment", simDefinition)
self.meanWindModel = meanWindModelFactory(envDictReader, silent=silent)
self.turbulenceModel = turbulenceModelFactory(envDictReader, silent=silent)
self.atmosphericModel = atmosphericModelFactory(envDictReader=envDictReader)
self.earthModel = earthModelFactory(envDictReader)
self.launchSiteElevation = envDictReader.tryGetFloat("LaunchSite.elevation")
self.launchSiteLatitude = envDictReader.tryGetFloat("LaunchSite.latitude")
self.launchSiteLongitude = envDictReader.tryGetFloat("LaunchSite.longitude")
# Check if being launched from a launch rail
launchRailLength = envDictReader.getFloat("LaunchSite.railLength")
if launchRailLength > 0:
# Initialize a launch rail, aligned with the rocket's initial direction
initialRocketPosition_towerFrame = envDictReader.getVector("Rocket.position")
# Check whether precise initial orientation has been specified
rotationAxis = envDictReader.tryGetVector("Rocket.rotationAxis", defaultValue=None)
if rotationAxis != None:
rotationAngle = math.radians(envDictReader.getFloat("Rocket.rotationAngle"))
initOrientation = Quaternion(rotationAxis, rotationAngle)
else:
# Calculate initial orientation quaternion in launch tower frame
rotationAxis = envDictReader.tryGetVector("Rocket.rotationAxis", defaultValue=None)
if rotationAxis != None:
rotationAngle = math.radians(self.rocketDictReader.getFloat("Rocket.rotationAngle"))
initOrientation = Quaternion(rotationAxis, rotationAngle)
else:
# Calculate initial orientation quaternion in launch tower frame
initialDirection = envDictReader.getVector("Rocket.initialDirection").normalize()
angleFromVertical = Vector(0,0,1).angle(initialDirection)
rotationAxis = Vector(0,0,1).crossProduct(initialDirection)
initOrientation = Quaternion(rotationAxis, angleFromVertical)
# TODO: Get from rocket, or calculate the same way - so that it works with rotationAxis + Angle
initialDirection = envDictReader.getVector("Rocket.initialDirection").normalize()
angleFromVertical = Vector(0,0,1).angle(initialDirection)
rotationAxis = Vector(0,0,1).crossProduct(initialDirection)
initOrientation = Quaternion(rotationAxis, angleFromVertical)
initPosition_seaLevelENUFrame = initialRocketPosition_towerFrame + Vector(0, 0, self.launchSiteElevation)
launchTowerState_local = RigidBodyState(position=initPosition_seaLevelENUFrame, orientation=initOrientation)
launchTowerState_global = self.earthModel.convertIntoGlobalFrame(launchTowerState_local, self.launchSiteLatitude, self.launchSiteLongitude)
towerDirection_global = launchTowerState_global.orientation.rotate(Vector(0, 0, 1))
self.launchRail = LaunchRail(launchTowerState_global.position, towerDirection_global, launchRailLength, earthRotationRate=self.earthModel.rotationRate)
else:
# Construct default environment from default parameters when no sim definition is passed in
# Need additional default value here in case a SimDefinition is not passed in (otherwise SimDefinition takes care of default values)
self.meanWindModel = meanWindModelFactory()
self.turbulenceModel = None
self.atmosphericModel = atmosphericModelFactory()
self.earthModel = earthModelFactory()
self.launchSiteElevation = float(defaultConfigValues["Environment.LaunchSite.elevation"])
self.launchSiteLatitude = float(defaultConfigValues["Environment.LaunchSite.latitude"])
self.launchSiteLongitude = float(defaultConfigValues["Environment.LaunchSite.longitude"])
