from dymos.transcriptions.transcription_base import TranscriptionBase
import csv
import warnings
import inspect
from pathlib import Path
from datetime import datetime
import importlib.util
import sys
import json
import enum
import numpy as np
import dymos as dm
from dymos.utils.misc import _unspecified
import openmdao.api as om
from openmdao.core.component import Component
from openmdao.utils.mpi import MPI
from openmdao.utils.reports_system import _default_reports
from aviary.constants import GRAV_ENGLISH_LBM, RHO_SEA_LEVEL_ENGLISH
from aviary.interface.default_phase_info.two_dof_fiti import add_default_sgm_args
from aviary.interface.utils.check_phase_info import check_phase_info
from aviary.mission.energy_phase import EnergyPhase
from aviary.mission.flops_based.phases.build_landing import Landing
from aviary.mission.flops_based.phases.build_takeoff import Takeoff
from aviary.mission.twodof_phase import TwoDOFPhase
from aviary.mission.gasp_based.idle_descent_estimation import add_descent_estimation_as_submodel
from aviary.mission.gasp_based.ode.params import ParamPort
from aviary.mission.gasp_based.phases.time_integration_traj import FlexibleTraj
from aviary.mission.gasp_based.phases.groundroll_phase import GroundrollPhase
from aviary.mission.flops_based.phases.groundroll_phase import GroundrollPhase as GroundrollPhaseVelocityIntegrated
from aviary.mission.gasp_based.phases.rotation_phase import RotationPhase
from aviary.mission.gasp_based.phases.climb_phase import ClimbPhase
from aviary.mission.gasp_based.phases.cruise_phase import CruisePhase
from aviary.mission.gasp_based.phases.accel_phase import AccelPhase
from aviary.mission.gasp_based.phases.ascent_phase import AscentPhase
from aviary.mission.gasp_based.phases.descent_phase import DescentPhase
from aviary.mission.gasp_based.ode.landing_ode import LandingSegment
from aviary.mission.gasp_based.ode.taxi_ode import TaxiSegment
from aviary.mission.gasp_based.phases.v_rotate_comp import VRotateComp
from aviary.mission.gasp_based.polynomial_fit import PolynomialFit
from aviary.mission.phase_builder_base import PhaseBuilderBase
from aviary.subsystems.aerodynamics.aerodynamics_builder import CoreAerodynamicsBuilder
from aviary.subsystems.geometry.geometry_builder import CoreGeometryBuilder
from aviary.subsystems.mass.mass_builder import CoreMassBuilder
from aviary.subsystems.premission import CorePreMission
from aviary.subsystems.propulsion.utils import build_engine_deck
from aviary.subsystems.propulsion.propulsion_builder import CorePropulsionBuilder
from aviary.utils.aviary_values import AviaryValues
from aviary.utils.functions import create_opts2vals, add_opts2vals, promote_aircraft_and_mission_vars, wrapped_convert_units
from aviary.utils.functions import convert_strings_to_data, set_value
from aviary.utils.merge_variable_metadata import merge_meta_data
from aviary.utils.preprocessors import preprocess_options
from aviary.utils.process_input_decks import create_vehicle, update_GASP_options, initialization_guessing
from aviary.variable_info.enums import AnalysisScheme, ProblemType, EquationsOfMotion, LegacyCode, Verbosity
from aviary.variable_info.functions import setup_trajectory_params, override_aviary_vars
from aviary.variable_info.variables import Aircraft, Mission, Dynamic, Settings
from aviary.variable_info.variable_meta_data import _MetaData as BaseMetaData
FLOPS = LegacyCode.FLOPS
GASP = LegacyCode.GASP
TWO_DEGREES_OF_FREEDOM = EquationsOfMotion.TWO_DEGREES_OF_FREEDOM
HEIGHT_ENERGY = EquationsOfMotion.HEIGHT_ENERGY
SOLVED_2DOF = EquationsOfMotion.SOLVED_2DOF
if hasattr(TranscriptionBase, 'setup_polynomial_controls'):
use_new_dymos_syntax = False
else:
use_new_dymos_syntax = True
[docs]
class PreMissionGroup(om.Group):
"""OpenMDAO group that holds all pre-mission systems"""
[docs]
class PostMissionGroup(om.Group):
"""OpenMDAO group that holds all post-mission systems"""
[docs]
def configure(self):
"""
Congigure this group for post-mission.
Promote aircraft and mission variables.
"""
promote_aircraft_and_mission_vars(self)
[docs]
class AviaryGroup(om.Group):
"""
A standard OpenMDAO group that handles Aviary's promotions in the configure
method. This assures that we only call set_input_defaults on variables
that are present in the model.
"""
[docs]
def initialize(self):
"""declare options"""
self.options.declare(
'aviary_options', types=AviaryValues,
desc='collection of Aircraft/Mission specific options')
self.options.declare(
'aviary_metadata', types=dict,
desc='metadata dictionary of the full aviary problem.')
self.options.declare(
'phase_info', types=dict,
desc='phase-specific settings.')
[docs]
class AviaryProblem(om.Problem):
"""
Main class for instantiating, formulating, and solving Aviary problems.
On a basic level, this problem object is all the conventional user needs
to interact with. Looking at the three "levels" of use cases, from simplest
to most complicated, we have:
Level 1: users interact with Aviary through input files (.csv or .yaml, TBD)
Level 2: users interact with Aviary through a Python interface
Level 3: users can modify Aviary's workings through Python and OpenMDAO
This Problem object is simply a specialized OpenMDAO Problem that has
additional methods to help users create and solve Aviary problems.
"""
[docs]
def __init__(self, analysis_scheme=AnalysisScheme.COLLOCATION, **kwargs):
# Modify OpenMDAO's default_reports for this session.
new_reports = ['subsystems', 'mission', 'timeseries_csv', 'run_status']
for report in new_reports:
if report not in _default_reports:
_default_reports.append(report)
super().__init__(**kwargs)
self.timestamp = datetime.now()
self.model = AviaryGroup()
self.pre_mission = PreMissionGroup()
self.post_mission = PostMissionGroup()
self.aviary_inputs = None
self.traj = None
self.analysis_scheme = analysis_scheme
self.regular_phases = []
self.reserve_phases = []
def _update_metadata_from_subsystems(self):
self.meta_data = BaseMetaData.copy()
# loop through phase_info and external subsystems
for phase_name in self.phase_info:
external_subsystems = self._get_all_subsystems(
self.phase_info[phase_name]['external_subsystems'])
for subsystem in external_subsystems:
meta_data = subsystem.meta_data.copy()
self.meta_data = merge_meta_data([self.meta_data, meta_data])
[docs]
def phase_separator(self):
"""
This method checks for reserve=True & False
Returns an error if a non-reserve phase is specified after a reserve phase.
return two dictionaries of phases: regular_phases and reserve_phases
For shooting trajectories, this will also check if a phase is part of the descent
"""
# Check to ensure no non-reserve phases are specified after reserve phases
start_reserve = False
raise_error = False
for idx, phase_name in enumerate(self.phase_info):
if 'user_options' in self.phase_info[phase_name]:
if 'reserve' in self.phase_info[phase_name]["user_options"]:
if self.phase_info[phase_name]["user_options"]["reserve"] is False:
# This is a regular phase
self.regular_phases.append(phase_name)
if start_reserve is True:
raise_error = True
else:
# This is a reserve phase
self.reserve_phases.append(phase_name)
start_reserve = True
else:
# This is a regular phase by default
self.regular_phases.append(phase_name)
if start_reserve is True:
raise_error = True
if raise_error is True:
raise ValueError(
f'In phase_info, reserve=False cannot be specified after a phase where reserve=True. '
f'All reserve phases must happen after non-reserve phases. '
f'Regular Phases : {self.regular_phases} | '
f'Reserve Phases : {self.reserve_phases} ')
if self.analysis_scheme is AnalysisScheme.SHOOTING:
self.descent_phases = {}
for name, info in self.phase_info.items():
descent = info.get('descent_phase', False)
if descent:
self.descent_phases[name] = info
[docs]
def add_pre_mission_systems(self):
"""
Add pre-mission systems to the Aviary problem. These systems are executed before the mission.
Depending on the mission model specified (`FLOPS` or `GASP`), this method adds various subsystems
to the aircraft model. For the `FLOPS` mission model, a takeoff phase is added using the Takeoff class
with the number of engines and airport altitude specified. For the `GASP` mission model, three subsystems
are added: a TaxiSegment subsystem, an ExecComp to calculate the time to initiate gear and flaps,
and an ExecComp to calculate the speed at which to initiate rotation. All subsystems are promoted with
aircraft and mission inputs and outputs as appropriate.
A user can override this method with their own pre-mission systems as desired.
"""
pre_mission = self.pre_mission
self.model.add_subsystem('pre_mission', pre_mission,
promotes_inputs=['aircraft:*', 'mission:*'],
promotes_outputs=['aircraft:*', 'mission:*'],)
if 'linear_solver' in self.pre_mission_info:
pre_mission.linear_solver = self.pre_mission_info['linear_solver']
if 'nonlinear_solver' in self.pre_mission_info:
pre_mission.nonlinear_solver = self.pre_mission_info['nonlinear_solver']
self._add_premission_external_subsystems()
subsystems = self.core_subsystems
# Propulsion isn't included in core pre-mission group to avoid override step in
# configure() - instead add it now
pre_mission.add_subsystem(
'core_propulsion', subsystems['propulsion'].build_pre_mission(
self.aviary_inputs),)
default_subsystems = [subsystems['geometry'],
subsystems['aerodynamics'],
subsystems['mass'],]
pre_mission.add_subsystem(
'core_subsystems',
CorePreMission(
aviary_options=self.aviary_inputs,
subsystems=default_subsystems,
process_overrides=False,
),
promotes_inputs=['*'],
promotes_outputs=['*'])
if not self.pre_mission_info['include_takeoff']:
return
# Check for 2DOF mission method
# NOTE should solved trigger this as well?
if self.mission_method is TWO_DEGREES_OF_FREEDOM:
self._add_two_dof_takeoff_systems()
# Check for HE mission method
elif self.mission_method is HEIGHT_ENERGY:
self._add_height_energy_takeoff_systems()
def _add_height_energy_takeoff_systems(self):
# Initialize takeoff options
takeoff_options = Takeoff(
airport_altitude=0., # ft
num_engines=self.aviary_inputs.get_val(Aircraft.Engine.NUM_ENGINES)
)
# Build and add takeoff subsystem
takeoff = takeoff_options.build_phase(False)
self.model.add_subsystem(
'takeoff', takeoff, promotes_inputs=['aircraft:*', 'mission:*'],
promotes_outputs=['mission:*'])
def _add_two_dof_takeoff_systems(self):
# Create options to values
OptionsToValues = create_opts2vals(
[Aircraft.CrewPayload.NUM_PASSENGERS,
Mission.Design.CRUISE_ALTITUDE, ])
add_opts2vals(self.model, OptionsToValues, self.aviary_inputs)
if self.analysis_scheme is AnalysisScheme.SHOOTING:
self._add_fuel_reserve_component(
post_mission=False, reserves_name='reserve_fuel_estimate')
add_default_sgm_args(self.descent_phases, self.ode_args)
add_descent_estimation_as_submodel(
self,
phases=self.descent_phases,
cruise_mach=self.cruise_mach,
cruise_alt=self.cruise_alt,
reserve_fuel='reserve_fuel_estimate',
all_subsystems=self._get_all_subsystems(),
)
# Add thrust-to-weight ratio subsystem
self.model.add_subsystem(
'tw_ratio',
om.ExecComp(
f'TW_ratio = Fn_SLS / (takeoff_mass * {GRAV_ENGLISH_LBM})',
TW_ratio={'units': "unitless"},
Fn_SLS={'units': 'lbf'},
takeoff_mass={'units': 'lbm'},
),
promotes_inputs=[('Fn_SLS', Aircraft.Propulsion.TOTAL_SCALED_SLS_THRUST),
('takeoff_mass', Mission.Summary.GROSS_MASS)],
promotes_outputs=[('TW_ratio', Aircraft.Design.THRUST_TO_WEIGHT_RATIO)],
)
self.cruise_alt = self.aviary_inputs.get_val(
Mission.Design.CRUISE_ALTITUDE, units='ft')
if self.analysis_scheme is AnalysisScheme.COLLOCATION:
# Add event transformation subsystem
self.model.add_subsystem(
"event_xform",
om.ExecComp(
["t_init_gear=m*tau_gear+b", "t_init_flaps=m*tau_flaps+b"],
t_init_gear={"units": "s"}, # initial time that gear comes up
t_init_flaps={"units": "s"}, # initial time that flaps retract
tau_gear={"units": "unitless"},
tau_flaps={"units": "unitless"},
m={"units": "s"},
b={"units": "s"},
),
promotes_inputs=[
"tau_gear", # design var
"tau_flaps", # design var
("m", Mission.Takeoff.ASCENT_DURATION),
("b", Mission.Takeoff.ASCENT_T_INTIIAL),
],
promotes_outputs=["t_init_gear", "t_init_flaps"], # link to h_fit
)
# Add taxi subsystem
self.model.add_subsystem(
"taxi", TaxiSegment(**(self.ode_args)),
promotes_inputs=['aircraft:*', 'mission:*'],
)
# Calculate speed at which to initiate rotation
self.model.add_subsystem(
"vrot",
om.ExecComp(
"Vrot = ((2 * mass * g) / (rho * wing_area * CLmax))**0.5 + dV1 + dVR",
Vrot={"units": "ft/s"},
mass={"units": "lbm"},
CLmax={"units": "unitless"},
g={"units": "lbf/lbm", "val": GRAV_ENGLISH_LBM},
rho={"units": "slug/ft**3", "val": RHO_SEA_LEVEL_ENGLISH},
wing_area={"units": "ft**2"},
dV1={
"units": "ft/s",
"desc": "Increment of engine failure decision speed above stall",
},
dVR={
"units": "ft/s",
"desc": "Increment of takeoff rotation speed above engine failure "
"decision speed",
},
),
promotes_inputs=[
("wing_area", Aircraft.Wing.AREA),
("dV1", Mission.Takeoff.DECISION_SPEED_INCREMENT),
("dVR", Mission.Takeoff.ROTATION_SPEED_INCREMENT),
("CLmax", Mission.Takeoff.LIFT_COEFFICIENT_MAX),
],
promotes_outputs=[('Vrot', Mission.Takeoff.ROTATION_VELOCITY)]
)
def _add_premission_external_subsystems(self):
"""
This private method adds each external subsystem to the pre-mission subsystem and
a mass component that captures external subsystem masses for use in mass buildups.
Firstly, the method iterates through all external subsystems in the pre-mission
information. For each subsystem, it builds the pre-mission instance of the
subsystem.
Secondly, the method collects the mass names of the added subsystems. This
expression is then used to define an ExecComp (a component that evaluates a
simple equation given input values).
The method promotes the input and output of this ExecComp to the top level of the
pre-mission object, allowing this calculated subsystem mass to be accessed
directly from the pre-mission object.
"""
mass_names = []
# Loop through all the phases in this subsystem.
for external_subsystem in self.pre_mission_info['external_subsystems']:
# Get all the subsystem builders for this phase.
subsystem_premission = external_subsystem.build_pre_mission(
self.aviary_inputs)
if subsystem_premission is not None:
self.pre_mission.add_subsystem(external_subsystem.name,
subsystem_premission)
mass_names.extend(external_subsystem.get_mass_names())
if mass_names:
formatted_names = []
for name in mass_names:
formatted_name = name.replace(':', '_')
formatted_names.append(formatted_name)
# Define the expression for computing the sum of masses
expr = 'subsystem_mass = ' + ' + '.join(formatted_names)
promotes_inputs_list = [
(formatted_name, original_name) for formatted_name,
original_name in zip(formatted_names, mass_names)]
# Create the ExecComp
self.pre_mission.add_subsystem(
'external_comp_sum', om.ExecComp(expr, units='kg'),
promotes_inputs=promotes_inputs_list,
promotes_outputs=[('subsystem_mass', Aircraft.Design.
EXTERNAL_SUBSYSTEMS_MASS)])
def _add_groundroll_eq_constraint(self):
"""
Add an equality constraint to the problem to ensure that the TAS at the end of the
groundroll phase is equal to the rotation velocity at the start of the rotation phase.
"""
self.model.add_subsystem(
"groundroll_boundary",
om.EQConstraintComp(
"velocity",
eq_units="ft/s",
normalize=True,
add_constraint=True,
),
)
self.model.connect(Mission.Takeoff.ROTATION_VELOCITY,
"groundroll_boundary.rhs:velocity")
self.model.connect(
"traj.groundroll.states:velocity",
"groundroll_boundary.lhs:velocity",
src_indices=[-1],
flat_src_indices=True,
)
def _get_phase(self, phase_name, phase_idx):
base_phase_options = self.phase_info[phase_name]
# We need to exclude some things from the phase_options that we pass down
# to the phases. Intead of "popping" keys, we just create new outer dictionaries.
phase_options = {}
for key, val in base_phase_options.items():
phase_options[key] = val
phase_options['user_options'] = {}
for key, val in base_phase_options['user_options'].items():
phase_options['user_options'][key] = val
# TODO optionally accept which subsystems to load from phase_info
subsystems = self.core_subsystems
default_mission_subsystems = [
subsystems['aerodynamics'], subsystems['propulsion']]
if self.mission_method is TWO_DEGREES_OF_FREEDOM:
if 'groundroll' in phase_name:
phase_builder = GroundrollPhase
elif 'rotation' in phase_name:
phase_builder = RotationPhase
elif 'accel' in phase_name:
phase_builder = AccelPhase
elif 'ascent' in phase_name:
phase_builder = AscentPhase
elif 'climb' in phase_name:
phase_builder = ClimbPhase
elif 'cruise' in phase_name:
phase_builder = CruisePhase
elif 'desc' in phase_name:
phase_builder = DescentPhase
else:
raise ValueError(
f'{phase_name} does not have an associated phase_builder \n phase_name must '
'include one of: groundroll, rotation, accel, ascent, climb, cruise, or desc')
if self.mission_method is HEIGHT_ENERGY:
if 'phase_builder' in phase_options:
phase_builder = phase_options['phase_builder']
if not issubclass(phase_builder, PhaseBuilderBase):
raise TypeError(f"phase_builder for the phase called "
"{phase_name} must be a PhaseBuilderBase object.")
else:
phase_builder = EnergyPhase
if self.mission_method is SOLVED_2DOF:
if phase_options['user_options']['ground_roll'] and phase_options['user_options']['fix_initial']:
phase_builder = GroundrollPhaseVelocityIntegrated
else:
phase_builder = TwoDOFPhase
phase_object = phase_builder.from_phase_info(
phase_name, phase_options, default_mission_subsystems,
meta_data=self.meta_data)
phase = phase_object.build_phase(aviary_options=self.aviary_inputs)
self.phase_objects.append(phase_object)
# TODO: add logic to filter which phases get which controls.
# right now all phases get all controls added from every subsystem.
# for example, we might only want ELECTRIC_SHAFT_POWER applied during the
# climb phase.
all_subsystems = self._get_all_subsystems(
phase_options['external_subsystems'])
# loop through all_subsystems and call `get_controls` on each subsystem
for subsystem in all_subsystems:
# add the controls from the subsystems to each phase
arg_spec = inspect.getfullargspec(subsystem.get_controls)
if 'phase_name' in arg_spec.args:
control_dicts = subsystem.get_controls(
phase_name=phase_name)
else:
control_dicts = subsystem.get_controls(
phase_name=phase_name)
for control_name, control_dict in control_dicts.items():
phase.add_control(control_name, **control_dict)
user_options = AviaryValues(phase_options.get('user_options', ()))
try:
fix_initial = user_options.get_val('fix_initial')
except KeyError:
fix_initial = False
try:
fix_duration = user_options.get_val('fix_duration')
except KeyError:
fix_duration = False
if 'ascent' in phase_name and self.mission_method is TWO_DEGREES_OF_FREEDOM:
phase.set_time_options(
units="s",
targets="t_curr",
input_initial=True,
input_duration=True,
)
elif 'cruise' in phase_name and self.mission_method is TWO_DEGREES_OF_FREEDOM:
# Time here is really the independent variable through which we are integrating.
# In the case of the Breguet Range ODE, it's mass.
# We rely on mass being monotonically non-increasing across the phase.
phase.set_time_options(
name='mass',
fix_initial=False,
fix_duration=False,
units="lbm",
targets="mass",
initial_bounds=(0., 1.e7),
initial_ref=100.e3,
duration_bounds=(-1.e7, -1),
duration_ref=50000,
)
elif 'descent' in phase_name and self.mission_method is TWO_DEGREES_OF_FREEDOM:
duration_ref = user_options.get_val("duration_ref", 's')
phase.set_time_options(
duration_bounds=duration_bounds,
fix_initial=fix_initial,
input_initial=input_initial,
units="s",
duration_ref=duration_ref,
)
else:
# The rest of the phases includes all Height Energy method phases
# and any 2DOF phases that don't fall into the naming patterns
# above.
input_initial = False
time_units = phase.time_options['units']
# Make a good guess for a reasonable intitial time scaler.
try:
initial_bounds = user_options.get_val('initial_bounds', units=time_units)
except KeyError:
initial_bounds = (None, None)
if initial_bounds[0] is not None and initial_bounds[1] != 0.0:
# Upper bound is good for a ref.
user_options.set_val('initial_ref', initial_bounds[1],
units=time_units)
else:
user_options.set_val('initial_ref', 600., time_units)
duration_bounds = user_options.get_val("duration_bounds", time_units)
user_options.set_val(
'duration_ref', (duration_bounds[0] + duration_bounds[1]) / 2.,
time_units
)
if phase_idx > 0:
input_initial = True
if fix_initial or input_initial:
if self.comm.size > 1:
# Phases are disconnected to run in parallel, so initial ref is
# valid.
initial_ref = user_options.get_val("initial_ref", time_units)
else:
# Redundant on a fixed input; raises a warning if specified.
initial_ref = None
phase.set_time_options(
fix_initial=fix_initial, fix_duration=fix_duration, units=time_units,
duration_bounds=user_options.get_val("duration_bounds", time_units),
duration_ref=user_options.get_val("duration_ref", time_units),
initial_ref=initial_ref,
)
elif phase_name == 'descent' and self.mission_method is HEIGHT_ENERGY: # TODO: generalize this logic for all phases
phase.set_time_options(
fix_initial=False, fix_duration=False, units=time_units,
duration_bounds=user_options.get_val("duration_bounds", time_units),
duration_ref=user_options.get_val("duration_ref", time_units),
initial_bounds=initial_bounds,
initial_ref=user_options.get_val("initial_ref", time_units),
)
else: # TODO: figure out how to handle this now that fix_initial is dict
phase.set_time_options(
fix_initial=fix_initial, fix_duration=fix_duration, units=time_units,
duration_bounds=user_options.get_val("duration_bounds", time_units),
duration_ref=user_options.get_val("duration_ref", time_units),
initial_bounds=initial_bounds,
initial_ref=user_options.get_val("initial_ref", time_units),
)
if 'cruise' not in phase_name and self.mission_method is TWO_DEGREES_OF_FREEDOM:
phase.add_control(
Dynamic.Vehicle.Propulsion.THROTTLE,
targets=Dynamic.Vehicle.Propulsion.THROTTLE,
units='unitless',
opt=False,
)
return phase
[docs]
def add_phases(self, phase_info_parameterization=None):
"""
Add the mission phases to the problem trajectory based on the user-specified
phase_info dictionary.
Parameters
----------
phase_info_parameterization (function, optional): A function that takes in the phase_info dictionary
and aviary_inputs and returns modified phase_info. Defaults to None.
Returns
-------
traj: The Dymos Trajectory object containing the added mission phases.
"""
if phase_info_parameterization is not None:
self.phase_info, self.post_mission_info = phase_info_parameterization(
self.phase_info, self.post_mission_info, self.aviary_inputs)
phase_info = self.phase_info
if self.analysis_scheme is AnalysisScheme.COLLOCATION:
phases = list(phase_info.keys())
traj = self.model.add_subsystem('traj', dm.Trajectory())
elif self.analysis_scheme is AnalysisScheme.SHOOTING:
vb = self.aviary_inputs.get_val(Settings.VERBOSITY)
add_default_sgm_args(self.phase_info, self.ode_args, vb)
full_traj = FlexibleTraj(
Phases=self.phase_info,
traj_final_state_output=[
Dynamic.Vehicle.MASS,
Dynamic.Mission.DISTANCE,
],
traj_initial_state_input=[
Dynamic.Vehicle.MASS,
Dynamic.Mission.DISTANCE,
Dynamic.Mission.ALTITUDE,
],
traj_event_trigger_input=[
# specify ODE, output_name, with units that SimuPyProblem expects
# assume event function is of form ODE.output_name - value
# third key is event_idx associated with input
(
'groundroll',
Dynamic.Mission.VELOCITY,
0,
),
(
'climb3',
Dynamic.Mission.ALTITUDE,
0,
),
(
'cruise',
Dynamic.Vehicle.MASS,
0,
),
],
traj_intermediate_state_output=[
('cruise', Dynamic.Mission.DISTANCE),
('cruise', Dynamic.Vehicle.MASS),
],
)
traj = self.model.add_subsystem(
'traj', full_traj, promotes_inputs=[
('altitude_initial', Mission.Design.CRUISE_ALTITUDE)])
self.model.add_subsystem(
'actual_descent_fuel', om.ExecComp(
'actual_descent_fuel = traj_cruise_mass_final - traj_mass_final',
actual_descent_fuel={'units': 'lbm'},
traj_cruise_mass_final={'units': 'lbm'},
traj_mass_final={'units': 'lbm'},))
self.model.connect('start_of_descent_mass', 'traj.SGMCruise_mass_trigger')
self.model.connect(
'traj.mass_final',
'actual_descent_fuel.traj_mass_final',
src_indices=[-1],
flat_src_indices=True,
)
self.model.connect(
'traj.cruise_mass_final',
'actual_descent_fuel.traj_cruise_mass_final',
src_indices=[-1],
flat_src_indices=True,
)
self.traj = full_traj
return traj
def add_subsystem_timeseries_outputs(phase, phase_name):
phase_options = self.phase_info[phase_name]
all_subsystems = self._get_all_subsystems(
phase_options['external_subsystems'])
for subsystem in all_subsystems:
timeseries_to_add = subsystem.get_outputs()
for timeseries in timeseries_to_add:
phase.add_timeseries_output(timeseries)
if self.mission_method in (TWO_DEGREES_OF_FREEDOM, HEIGHT_ENERGY, SOLVED_2DOF):
if self.analysis_scheme is AnalysisScheme.COLLOCATION:
self.phase_objects = []
for phase_idx, phase_name in enumerate(phases):
phase = traj.add_phase(
phase_name, self._get_phase(phase_name, phase_idx))
add_subsystem_timeseries_outputs(phase, phase_name)
if self.mission_method is TWO_DEGREES_OF_FREEDOM:
# In GASP, we still use the phase name to infer the phase type.
# We need this information to be available in the builders.
# TODO - Ultimately we should overhaul all of this.
self.phase_info[phase_name]['phase_type'] = phase_name
if phase_name == 'ascent':
self._add_groundroll_eq_constraint()
# loop through phase_info and external subsystems
external_parameters = {}
for phase_name in self.phase_info:
external_parameters[phase_name] = {}
all_subsystems = self._get_all_subsystems(
self.phase_info[phase_name]['external_subsystems'])
for subsystem in all_subsystems:
parameter_dict = subsystem.get_parameters(
phase_info=self.phase_info[phase_name],
aviary_inputs=self.aviary_inputs
)
for parameter in parameter_dict:
external_parameters[phase_name][parameter] = parameter_dict[parameter]
traj = setup_trajectory_params(
self.model, traj, self.aviary_inputs, phases, meta_data=self.meta_data,
external_parameters=external_parameters)
if self.mission_method is HEIGHT_ENERGY:
if not self.pre_mission_info['include_takeoff']:
first_flight_phase_name = list(phase_info.keys())[0]
first_flight_phase = traj._phases[first_flight_phase_name]
first_flight_phase.set_state_options(
Dynamic.Vehicle.MASS, fix_initial=False
)
self.traj = traj
return traj
[docs]
def add_post_mission_systems(self, include_landing=True):
"""
Add post-mission systems to the aircraft model. This is akin to the pre-mission group
or the "premission_systems", but occurs after the mission in the execution order.
Depending on the mission model specified (`FLOPS` or `GASP`), this method adds various subsystems
to the aircraft model. For the `FLOPS` mission model, a landing phase is added using the Landing class
with the wing area and lift coefficient specified, and a takeoff constraints ExecComp is added to enforce
mass, range, velocity, and altitude continuity between the takeoff and climb phases. The landing subsystem
is promoted with aircraft and mission inputs and outputs as appropriate, while the takeoff constraints ExecComp
is only promoted with mission inputs and outputs.
For the `GASP` mission model, four subsystems are added: a LandingSegment subsystem, an ExecComp to calculate
the reserve fuel required, an ExecComp to calculate the overall fuel burn, and three ExecComps to calculate
various mission objectives and constraints. All subsystems are promoted with aircraft and mission inputs and
outputs as appropriate.
A user can override this with their own postmission systems.
"""
if self.pre_mission_info['include_takeoff'] and self.mission_method is HEIGHT_ENERGY:
self._add_post_mission_takeoff_systems()
if include_landing and self.post_mission_info['include_landing']:
if self.mission_method is HEIGHT_ENERGY:
self._add_height_energy_landing_systems()
elif self.mission_method is TWO_DEGREES_OF_FREEDOM:
self._add_two_dof_landing_systems()
self.model.add_subsystem('post_mission', self.post_mission,
promotes_inputs=['*'],
promotes_outputs=['*'])
# Loop through all the phases in this subsystem.
for external_subsystem in self.post_mission_info['external_subsystems']:
# Get all the subsystem builders for this phase.
subsystem_postmission = external_subsystem.build_post_mission(
self.aviary_inputs)
if subsystem_postmission is not None:
self.post_mission.add_subsystem(external_subsystem.name,
subsystem_postmission)
if self.mission_method in (HEIGHT_ENERGY, SOLVED_2DOF, TWO_DEGREES_OF_FREEDOM):
# Check if regular_phases[] is accessible
try:
self.regular_phases[0]
except BaseException:
raise ValueError(
f"regular_phases[] dictionary is not accessible."
f" For HEIGHT_ENERGY and SOLVED_2DOF missions, check_and_preprocess_inputs()"
f" must be called before add_post_mission_systems().")
# Fuel burn in regular phases
ecomp = om.ExecComp('fuel_burned = initial_mass - mass_final',
initial_mass={'units': 'lbm'},
mass_final={'units': 'lbm'},
fuel_burned={'units': 'lbm'})
self.post_mission.add_subsystem(
'fuel_burned', ecomp,
promotes=[('fuel_burned', Mission.Summary.FUEL_BURNED)])
if self.analysis_scheme is AnalysisScheme.SHOOTING:
# shooting method currently doesn't have timeseries
self.post_mission.promotes('fuel_burned', [
('initial_mass', Mission.Summary.GROSS_MASS),
('mass_final', Mission.Landing.TOUCHDOWN_MASS),
])
else:
if self.pre_mission_info['include_takeoff']:
self.post_mission.promotes('fuel_burned', [
('initial_mass', Mission.Summary.GROSS_MASS),
])
else:
# timeseries has to be used because Breguet cruise phases don't have
# states
self.model.connect(f"traj.{self.regular_phases[0]}.timeseries.mass",
"fuel_burned.initial_mass", src_indices=[0])
self.model.connect(f"traj.{self.regular_phases[-1]}.timeseries.mass",
"fuel_burned.mass_final", src_indices=[-1])
# Fuel burn in reserve phases
if self.reserve_phases:
ecomp = om.ExecComp('reserve_fuel_burned = initial_mass - mass_final',
initial_mass={'units': 'lbm'},
mass_final={'units': 'lbm'},
reserve_fuel_burned={'units': 'lbm'})
self.post_mission.add_subsystem(
'reserve_fuel_burned', ecomp, promotes=[
('reserve_fuel_burned', Mission.Summary.RESERVE_FUEL_BURNED)])
if self.analysis_scheme is AnalysisScheme.SHOOTING:
# shooting method currently doesn't have timeseries
self.post_mission.promotes('reserve_fuel_burned', [
('initial_mass', Mission.Landing.TOUCHDOWN_MASS),
])
self.model.connect(
f"traj.{self.reserve_phases[-1]}.states:mass",
"reserve_fuel_burned.mass_final", src_indices=[-1])
else:
# timeseries has to be used because Breguet cruise phases don't have
# states
self.model.connect(
f"traj.{self.reserve_phases[0]}.timeseries.mass",
"reserve_fuel_burned.initial_mass", src_indices=[0])
self.model.connect(
f"traj.{self.reserve_phases[-1]}.timeseries.mass",
"reserve_fuel_burned.mass_final", src_indices=[-1])
self._add_fuel_reserve_component()
# TODO: need to add some sort of check that this value is less than the fuel capacity
# TODO: the overall_fuel variable is the burned fuel plus the reserve, but should
# also include the unused fuel, and the hierarchy variable name should be
# more clear
ecomp = om.ExecComp('overall_fuel = (1 + fuel_margin/100)*fuel_burned + reserve_fuel',
overall_fuel={'units': 'lbm', 'shape': 1},
fuel_margin={"units": "unitless", 'val': 0},
fuel_burned={'units': 'lbm'}, # from regular_phases only
reserve_fuel={'units': 'lbm', 'shape': 1},
)
self.post_mission.add_subsystem(
'fuel_calc', ecomp,
promotes_inputs=[
("fuel_margin", Aircraft.Fuel.FUEL_MARGIN),
('fuel_burned', Mission.Summary.FUEL_BURNED),
("reserve_fuel", Mission.Design.RESERVE_FUEL),
],
promotes_outputs=[('overall_fuel', Mission.Summary.TOTAL_FUEL_MASS)])
# If a target distance (or time) has been specified for this phase
# distance (or time) is measured from the start of this phase to the end
# of this phase
for phase_name in self.phase_info:
if 'target_distance' in self.phase_info[phase_name]["user_options"]:
target_distance = wrapped_convert_units(
self.phase_info[phase_name]["user_options"]
["target_distance"],
'nmi')
self.post_mission.add_subsystem(
f"{phase_name}_distance_constraint", om.ExecComp(
"distance_resid = target_distance - (final_distance - initial_distance)",
distance_resid={'units': 'nmi'},
target_distance={'val': target_distance, 'units': 'nmi'},
final_distance={'units': 'nmi'},
initial_distance={'units': 'nmi'},))
self.model.connect(
f"traj.{phase_name}.timeseries.distance",
f"{phase_name}_distance_constraint.final_distance",
src_indices=[-1])
self.model.connect(
f"traj.{phase_name}.timeseries.distance",
f"{phase_name}_distance_constraint.initial_distance",
src_indices=[0])
self.model.add_constraint(
f"{phase_name}_distance_constraint.distance_resid", equals=0.0, ref=1e2)
# this is only used for analytic phases with a target duration
if 'target_duration' in self.phase_info[phase_name]["user_options"] and \
self.phase_info[phase_name]["user_options"].get("analytic", False):
target_duration = wrapped_convert_units(
self.phase_info[phase_name]["user_options"]
["target_duration"],
'min')
self.post_mission.add_subsystem(
f"{phase_name}_duration_constraint", om.ExecComp(
"duration_resid = target_duration - (final_time - initial_time)",
duration_resid={'units': 'min'},
target_duration={'val': target_duration, 'units': 'min'},
final_time={'units': 'min'},
initial_time={'units': 'min'},))
self.model.connect(
f"traj.{phase_name}.timeseries.time",
f"{phase_name}_duration_constraint.final_time", src_indices=[-1])
self.model.connect(
f"traj.{phase_name}.timeseries.time",
f"{phase_name}_duration_constraint.initial_time",
src_indices=[0])
self.model.add_constraint(
f"{phase_name}_duration_constraint.duration_resid", equals=0.0, ref=1e2)
if self.mission_method in (TWO_DEGREES_OF_FREEDOM, HEIGHT_ENERGY):
self._add_objectives()
ecomp = om.ExecComp(
'mass_resid = operating_empty_mass + overall_fuel + payload_mass -'
' initial_mass',
operating_empty_mass={'units': 'lbm'},
overall_fuel={'units': 'lbm'},
payload_mass={'units': 'lbm'},
initial_mass={'units': 'lbm'},
mass_resid={'units': 'lbm'})
if self.mass_method is GASP:
payload_mass_src = Aircraft.CrewPayload.PASSENGER_PAYLOAD_MASS
else:
payload_mass_src = Aircraft.CrewPayload.TOTAL_PAYLOAD_MASS
self.post_mission.add_subsystem(
'mass_constraint', ecomp,
promotes_inputs=[
('operating_empty_mass', Aircraft.Design.OPERATING_MASS),
('overall_fuel', Mission.Summary.TOTAL_FUEL_MASS),
('payload_mass', payload_mass_src),
('initial_mass', Mission.Summary.GROSS_MASS)],
promotes_outputs=[("mass_resid", Mission.Constraints.MASS_RESIDUAL)])
if self.mission_method in (HEIGHT_ENERGY, TWO_DEGREES_OF_FREEDOM):
self.post_mission.add_constraint(
Mission.Constraints.MASS_RESIDUAL, equals=0.0, ref=1.e5)
if self.mission_method is HEIGHT_ENERGY:
# connect summary mass to the initial guess of mass in the first phase
if not self.pre_mission_info['include_takeoff']:
first_flight_phase_name = list(self.phase_info.keys())[0]
eq = self.model.add_subsystem(
f'link_{first_flight_phase_name}_mass', om.EQConstraintComp(),
promotes_inputs=[('rhs:mass', Mission.Summary.GROSS_MASS)])
eq.add_eq_output('mass', eq_units='lbm', normalize=False,
ref=100000., add_constraint=True)
self.model.connect(
f'traj.{first_flight_phase_name}.states:mass',
f'link_{first_flight_phase_name}_mass.lhs:mass',
src_indices=[0],
flat_src_indices=True,
)
def _link_phases_helper_with_options(self, phases, option_name, var, **kwargs):
# Initialize a list to keep track of indices where option_name is True
true_option_indices = []
# Loop through phases to find where option_name is True
for idx, phase_name in enumerate(phases):
if self.phase_info[phase_name]['user_options'].get(option_name, False):
true_option_indices.append(idx)
# Determine the groups of phases to link based on consecutive indices
groups_to_link = []
current_group = []
for idx in true_option_indices:
if not current_group or idx == current_group[-1] + 1:
# If the current index is consecutive, add it to the current group
current_group.append(idx)
else:
# Otherwise, start a new group and save the previous one
groups_to_link.append(current_group)
current_group = [idx]
# Add the last group if it exists
if current_group:
groups_to_link.append(current_group)
# Loop through each group and determine the phases to link
for group in groups_to_link:
# Extend the group to include the phase before the first True option and
# after the last True option, if applicable
if group[0] > 0:
group.insert(0, group[0] - 1)
if group[-1] < len(phases) - 1:
group.append(group[-1] + 1)
# Extract the phase names for the current group
phases_to_link = [phases[idx] for idx in group]
# Link the phases for the current group
if len(phases_to_link) > 1:
self.traj.link_phases(phases=phases_to_link, vars=[var], **kwargs)
[docs]
def link_phases(self):
"""
Link phases together after they've been added.
Based on which phases the user has selected, we might need
special logic to do the Dymos linkages correctly. Some of those
connections for the simple GASP and FLOPS mission are shown here.
"""
self._add_bus_variables_and_connect()
phases = list(self.phase_info.keys())
if len(phases) <= 1:
return
# In summary, the following code loops over all phases in self.phase_info, gets
# the linked variables from each external subsystem in each phase, and stores
# the lists of linked variables in lists_to_link. It then gets a list of
# unique variable names from lists_to_link and loops over them, creating
# a list of phase names for each variable and linking the phases
# using self.traj.link_phases().
lists_to_link = []
for idx, phase_name in enumerate(self.phase_info):
lists_to_link.append([])
for external_subsystem in self.phase_info[phase_name]['external_subsystems']:
lists_to_link[idx].extend(external_subsystem.get_linked_variables())
# get unique variable names from lists_to_link
unique_vars = list(set([var for sublist in lists_to_link for var in sublist]))
# Phase linking.
# If we are under mpi, and traj.phases is running in parallel, then let the
# optimizer handle the linkage constraints. Note that we can technically
# paralellize connected phases, but it requires a solver that we would like
# to avoid.
true_unless_mpi = True
if self.comm.size > 1 and self.traj.options['parallel_phases']:
true_unless_mpi = False
# loop over unique variable names
for var in unique_vars:
phases_to_link = []
for idx, phase_name in enumerate(self.phase_info):
if var in lists_to_link[idx]:
phases_to_link.append(phase_name)
if len(phases_to_link) > 1: # TODO: hack
self.traj.link_phases(phases=phases_to_link, vars=[var], connected=True)
if self.mission_method in (HEIGHT_ENERGY, SOLVED_2DOF):
# connect regular_phases with each other if you are optimizing alt or mach
self._link_phases_helper_with_options(
self.regular_phases,
'optimize_altitude',
Dynamic.Mission.ALTITUDE,
ref=1.0e4,
)
self._link_phases_helper_with_options(
self.regular_phases, 'optimize_mach', Dynamic.Atmosphere.MACH
)
# connect reserve phases with each other if you are optimizing alt or mach
self._link_phases_helper_with_options(
self.reserve_phases,
'optimize_altitude',
Dynamic.Mission.ALTITUDE,
ref=1.0e4,
)
self._link_phases_helper_with_options(
self.reserve_phases, 'optimize_mach', Dynamic.Atmosphere.MACH
)
if self.mission_method is HEIGHT_ENERGY:
# connect mass and distance between all phases regardless of reserve /
# non-reserve status
self.traj.link_phases(phases, ["time"],
ref=None if true_unless_mpi else 1e3,
connected=true_unless_mpi)
self.traj.link_phases(phases, [Dynamic.Vehicle.MASS],
ref=None if true_unless_mpi else 1e6,
connected=true_unless_mpi)
self.traj.link_phases(phases, [Dynamic.Mission.DISTANCE],
ref=None if true_unless_mpi else 1e3,
connected=true_unless_mpi)
self.model.connect(f'traj.{self.regular_phases[-1]}.timeseries.distance',
'actual_range',
src_indices=[-1], flat_src_indices=True)
elif self.mission_method is SOLVED_2DOF:
self.traj.link_phases(phases, [Dynamic.Vehicle.MASS], connected=True)
self.traj.link_phases(
phases, [Dynamic.Mission.DISTANCE],
units='ft', ref=1.e3, connected=False)
self.traj.link_phases(phases, ["time"], connected=False)
if len(phases) > 2:
self.traj.link_phases(
phases[1:], ["alpha"], units='rad', connected=False)
elif self.mission_method is TWO_DEGREES_OF_FREEDOM:
if self.analysis_scheme is AnalysisScheme.COLLOCATION:
for ii in range(len(phases) - 1):
phase1, phase2 = phases[ii:ii + 2]
analytic1 = self.phase_info[phase1]['user_options']['analytic']
analytic2 = self.phase_info[phase2]['user_options']['analytic']
if not (analytic1 or analytic2):
# we always want time, distance, and mass to be continuous
states_to_link = {
'time': true_unless_mpi,
Dynamic.Mission.DISTANCE: true_unless_mpi,
Dynamic.Vehicle.MASS: False,
}
# if both phases are reserve phases or neither is a reserve phase
# (we are not on the boundary between the regular and reserve missions)
# and neither phase is ground roll or rotation (altitude isn't a state):
# we want altitude to be continous as well
if ((phase1 in self.reserve_phases) == (phase2 in self.reserve_phases)) and \
not ({"groundroll", "rotation"} & {phase1, phase2}) and \
not ('accel', 'climb1') == (phase1, phase2): # required for convergence of FwGm
states_to_link[Dynamic.Mission.ALTITUDE] = true_unless_mpi
# if either phase is rotation, we need to connect velocity
# ascent to accel also requires velocity
if 'rotation' in (
phase1, phase2) or (
'ascent', 'accel') == (
phase1, phase2):
states_to_link[Dynamic.Mission.VELOCITY] = true_unless_mpi
# if the first phase is rotation, we also need alpha
if phase1 == 'rotation':
states_to_link['alpha'] = False
for state, connected in states_to_link.items():
# in initial guesses, all of the states, other than time use
# the same name
initial_guesses1 = self.phase_info[phase1]['initial_guesses']
initial_guesses2 = self.phase_info[phase2]['initial_guesses']
# if a state is in the initial guesses, get the units of the
# initial guess
kwargs = {}
if not connected:
if state in initial_guesses1:
kwargs = {'units': initial_guesses1[state][-1]}
elif state in initial_guesses2:
kwargs = {'units': initial_guesses2[state][-1]}
self.traj.link_phases(
[phase1, phase2], [state], connected=connected, **kwargs)
# if either phase is analytic we have to use a linkage_constraint
else:
# analytic phases use the prefix "initial" for time and distance,
# but not mass
if analytic2:
prefix = 'initial_'
else:
prefix = ''
self.traj.add_linkage_constraint(
phase1, phase2, 'time', prefix + 'time', connected=True)
self.traj.add_linkage_constraint(
phase1, phase2, 'distance', prefix + 'distance',
connected=True)
self.traj.add_linkage_constraint(
phase1, phase2, 'mass', 'mass', connected=False, ref=1.0e5)
# add all params and promote them to self.model level
ParamPort.promote_params(
self.model,
trajs=["traj"],
phases=[
[*self.regular_phases,
*self.reserve_phases]
],
)
self.model.promotes(
"traj",
inputs=[
("ascent.parameters:t_init_gear", "t_init_gear"),
("ascent.parameters:t_init_flaps", "t_init_flaps"),
("ascent.t_initial", Mission.Takeoff.ASCENT_T_INTIIAL),
("ascent.t_duration", Mission.Takeoff.ASCENT_DURATION),
],
)
# imitate input_initial for taxi -> groundroll
eq = self.model.add_subsystem(
"taxi_groundroll_mass_constraint", om.EQConstraintComp())
eq.add_eq_output("mass", eq_units="lbm", normalize=False,
ref=10000., add_constraint=True)
self.model.connect(
"taxi.mass", "taxi_groundroll_mass_constraint.rhs:mass")
self.model.connect(
"traj.groundroll.states:mass",
"taxi_groundroll_mass_constraint.lhs:mass",
src_indices=[0],
flat_src_indices=True,
)
self.model.connect("traj.ascent.timeseries.time", "h_fit.time_cp")
self.model.connect(
"traj.ascent.timeseries.altitude", "h_fit.h_cp")
self.model.connect(f'traj.{self.regular_phases[-1]}.states:mass',
Mission.Landing.TOUCHDOWN_MASS, src_indices=[-1])
connect_map = {
f"traj.{self.regular_phases[-1]}.timeseries.distance": 'actual_range',
}
else:
connect_map = {
"taxi.mass": "traj.mass_initial",
Mission.Takeoff.ROTATION_VELOCITY: "traj.SGMGroundroll_velocity_trigger",
"traj.distance_final": 'actual_range',
"traj.mass_final": Mission.Landing.TOUCHDOWN_MASS,
}
# promote all ParamPort inputs for analytic segments as well
param_list = list(ParamPort.param_data)
self.model.promotes("taxi", inputs=param_list)
self.model.promotes("landing", inputs=param_list)
if self.analysis_scheme is AnalysisScheme.SHOOTING:
param_list.append(Aircraft.Design.MAX_FUSELAGE_PITCH_ANGLE)
self.model.promotes("traj", inputs=param_list)
# self.model.list_inputs()
# self.model.promotes("traj", inputs=['ascent.ODE_group.eoms.'+Aircraft.Design.MAX_FUSELAGE_PITCH_ANGLE])
self.model.connect("taxi.mass", "vrot.mass")
def connect_with_common_params(self, source, target):
self.model.connect(
source,
target,
src_indices=[-1],
flat_src_indices=True,
)
for source, target in connect_map.items():
connect_with_common_params(self, source, target)
[docs]
def add_driver(
self, optimizer=None, use_coloring=None, max_iter=50,
verbosity=Verbosity.BRIEF):
"""
Add an optimization driver to the Aviary problem.
Depending on the provided optimizer, the method instantiates the relevant driver (ScipyOptimizeDriver or
pyOptSparseDriver) and sets the optimizer options. Options for 'SNOPT', 'IPOPT', and 'SLSQP' are
specified. The method also allows for the declaration of coloring and setting debug print options.
Parameters
----------
optimizer : str
The name of the optimizer to use. It can be "SLSQP", "SNOPT", "IPOPT" or others supported by OpenMDAO.
If "SLSQP", it will instantiate a ScipyOptimizeDriver, else it will instantiate a pyOptSparseDriver.
use_coloring : bool, optional
If True (default), the driver will declare coloring, which can speed up derivative computations.
max_iter : int, optional
The maximum number of iterations allowed for the optimization process. Default is 50. This option is
applicable to "SNOPT", "IPOPT", and "SLSQP" optimizers.
verbosity : Verbosity, int or list, optional
If Verbosity.DEBUG, debug print options ['desvars','ln_cons','nl_cons','objs'] will be set. If a list is
provided, it will be used as the debug print options.
Returns
-------
None
"""
# compatibility with being passed int for verbosity
verbosity = Verbosity(verbosity)
# Set defaults for optimizer and use_coloring based on analysis scheme
if optimizer is None:
optimizer = 'IPOPT' if self.analysis_scheme is AnalysisScheme.SHOOTING else 'SNOPT'
if use_coloring is None:
use_coloring = False if self.analysis_scheme is AnalysisScheme.SHOOTING else True
# check if optimizer is SLSQP
if optimizer == "SLSQP":
driver = self.driver = om.ScipyOptimizeDriver()
else:
driver = self.driver = om.pyOptSparseDriver()
driver.options["optimizer"] = optimizer
if use_coloring:
driver.declare_coloring()
if driver.options["optimizer"] == "SNOPT":
if verbosity == Verbosity.QUIET:
isumm, iprint = 0, 0
elif verbosity == Verbosity.BRIEF:
isumm, iprint = 6, 0
elif verbosity > Verbosity.BRIEF:
isumm, iprint = 6, 9
driver.opt_settings["Major iterations limit"] = max_iter
driver.opt_settings["Major optimality tolerance"] = 1e-4
driver.opt_settings["Major feasibility tolerance"] = 1e-7
driver.opt_settings["iSumm"] = isumm
driver.opt_settings["iPrint"] = iprint
elif driver.options["optimizer"] == "IPOPT":
if verbosity == Verbosity.QUIET:
print_level = 3 # minimum to get exit status
driver.opt_settings['print_user_options'] = 'no'
elif verbosity == Verbosity.BRIEF:
print_level = 5
driver.opt_settings['print_user_options'] = 'no'
driver.opt_settings['print_frequency_iter'] = 10
elif verbosity == Verbosity.VERBOSE:
print_level = 5
else: # DEBUG
print_level = 7
driver.opt_settings['tol'] = 1.0E-6
driver.opt_settings['mu_init'] = 1e-5
driver.opt_settings['max_iter'] = max_iter
driver.opt_settings['print_level'] = print_level
# for faster convergence
driver.opt_settings['nlp_scaling_method'] = 'gradient-based'
driver.opt_settings['alpha_for_y'] = 'safer-min-dual-infeas'
driver.opt_settings['mu_strategy'] = 'monotone'
elif driver.options["optimizer"] == "SLSQP":
if verbosity == Verbosity.QUIET:
disp = False
else:
disp = True
driver.options["tol"] = 1e-9
driver.options["maxiter"] = max_iter
driver.options["disp"] = disp
if verbosity > Verbosity.QUIET:
if isinstance(verbosity, list):
driver.options['debug_print'] = verbosity
elif verbosity == Verbosity.DEBUG:
driver.options['debug_print'] = ['desvars', 'ln_cons', 'nl_cons', 'objs']
if optimizer in ("SNOPT", "IPOPT"):
if verbosity == Verbosity.QUIET:
driver.options['print_results'] = False
elif verbosity < Verbosity.DEBUG:
driver.options['print_results'] = 'minimal'
[docs]
def add_design_variables(self):
"""
Adds design variables to the Aviary problem.
Depending on the mission model and problem type, different design variables and constraints are added.
If using the FLOPS model, a design variable is added for the gross mass of the aircraft, with a lower bound of 10 lbm and an upper bound of 900,000 lbm.
If using the GASP model, the following design variables are added depending on the mission type:
- the initial thrust-to-weight ratio of the aircraft during ascent
- the duration of the ascent phase
- the time constant for the landing gear actuation
- the time constant for the flaps actuation
In addition, two constraints are added for the GASP model:
- the initial altitude of the aircraft with gear extended is constrained to be 50 ft
- the initial altitude of the aircraft with flaps extended is constrained to be 400 ft
If solving a sizing problem, a design variable is added for the gross mass of the aircraft, and another for the gross mass of the aircraft computed during the mission. A constraint is also added to ensure that the residual range is zero.
If solving an alternate problem, only a design variable for the gross mass of the aircraft computed during the mission is added. A constraint is also added to ensure that the residual range is zero.
In all cases, a design variable is added for the final cruise mass of the aircraft, with no upper bound, and a residual mass constraint is added to ensure that the mass balances.
"""
# add the engine builder `get_design_vars` dict to a collected dict from
# the external subsystems
# TODO : maybe in the most general case we need to handle DVs in the mission and post-mission as well.
# for right now we just handle pre_mission
all_subsystems = self._get_all_subsystems()
# loop through all_subsystems and call `get_design_vars` on each subsystem
for subsystem in all_subsystems:
dv_dict = subsystem.get_design_vars()
for dv_name, dv_dict in dv_dict.items():
self.model.add_design_var(dv_name, **dv_dict)
if self.mission_method is SOLVED_2DOF:
optimize_mass = self.pre_mission_info.get('optimize_mass')
if optimize_mass:
self.model.add_design_var(Mission.Design.GROSS_MASS, units='lbm',
lower=10, upper=900.e3, ref=175.e3)
elif self.mission_method in (HEIGHT_ENERGY, TWO_DEGREES_OF_FREEDOM):
# vehicle sizing problem
# size the vehicle (via design GTOW) to meet a target range using all fuel
# capacity
if self.problem_type is ProblemType.SIZING:
self.model.add_design_var(
Mission.Design.GROSS_MASS,
lower=10.0,
upper=None,
units='lbm',
ref=175e3,
)
self.model.add_design_var(
Mission.Summary.GROSS_MASS,
lower=10.0,
upper=None,
units='lbm',
ref=175e3,
)
self.model.add_subsystem(
'gtow_constraint',
om.EQConstraintComp(
'GTOW',
eq_units='lbm',
normalize=True,
add_constraint=True,
),
promotes_inputs=[
('lhs:GTOW', Mission.Design.GROSS_MASS),
('rhs:GTOW', Mission.Summary.GROSS_MASS),
],
)
if self.require_range_residual:
self.model.add_constraint(
Mission.Constraints.RANGE_RESIDUAL, equals=0, ref=10
)
# target range problem
# fixed vehicle (design GTOW) but variable actual GTOW for off-design
# mission range
elif self.problem_type is ProblemType.ALTERNATE:
self.model.add_design_var(
Mission.Summary.GROSS_MASS,
lower=10.,
upper=900e3,
units='lbm',
ref=175e3,
)
self.model.add_constraint(
Mission.Constraints.RANGE_RESIDUAL, equals=0, ref=10
)
elif self.problem_type is ProblemType.FALLOUT:
print('No design variables for Fallout missions')
elif self.problem_type is ProblemType.MULTI_MISSION:
self.model.add_design_var(
Mission.Summary.GROSS_MASS,
lower=10.,
upper=900e3,
units='lbm',
ref=175e3,
)
self.model.add_constraint(
Mission.Constraints.RANGE_RESIDUAL, equals=0, ref=10
)
# We must ensure that design.gross_mass is greater than mission.summary.gross_mass
# and this must hold true for each of the different missions that is flown
# the result will be the design.gross_mass should be equal to the mission.summary.gross_mass
# of the heaviest mission
self.model.add_subsystem(
"GROSS_MASS_constraint",
om.ExecComp(
"gross_mass_resid = design_mass - actual_mass",
design_mass={"val": 1, "units": "kg"},
actual_mass={"val": 0, "units": "kg"},
gross_mass_resid={"val": 30, "units": "kg"},
),
promotes_inputs=[
("design_mass", Mission.Design.GROSS_MASS),
("actual_mass", Mission.Summary.GROSS_MASS),
],
promotes_outputs=["gross_mass_resid"],
)
self.model.add_constraint(
"gross_mass_resid", lower=0
)
if self.mission_method is TWO_DEGREES_OF_FREEDOM and self.analysis_scheme is AnalysisScheme.COLLOCATION:
# problem formulation to make the trajectory work
self.model.add_design_var(Mission.Takeoff.ASCENT_T_INTIIAL,
lower=0, upper=100, ref=30.0)
self.model.add_design_var(Mission.Takeoff.ASCENT_DURATION,
lower=1, upper=1000, ref=10.)
self.model.add_design_var("tau_gear", lower=0.01,
upper=1.0, units="unitless", ref=1)
self.model.add_design_var("tau_flaps", lower=0.01,
upper=1.0, units="unitless", ref=1)
self.model.add_constraint(
"h_fit.h_init_gear", equals=50.0, units="ft", ref=50.0)
self.model.add_constraint("h_fit.h_init_flaps",
equals=400.0, units="ft", ref=400.0)
[docs]
def add_objective(self, objective_type=None, ref=None):
"""
Add the objective function based on the given objective_type and ref.
NOTE: the ref value should be positive for values you're trying
to minimize and negative for values you're trying to maximize.
Please check and double-check that your ref value makes sense
for the objective you're using.
Parameters
----------
objective_type : str
The type of objective to add. Options are 'mass', 'hybrid_objective', 'fuel_burned', and 'fuel'.
ref : float
The reference value for the objective. If None, a default value will be used based on the objective type. Please see the
`default_ref_values` dict for these default values.
Raises
------
ValueError: If an invalid problem type is provided.
"""
# Dictionary for default reference values
default_ref_values = {
'mass': -5e4,
'hybrid_objective': -5e4,
'fuel_burned': 1e4,
'fuel': 1e4
}
# Check if an objective type is specified
if objective_type is not None:
ref = ref if ref is not None else default_ref_values.get(objective_type, 1)
final_phase_name = self.regular_phases[-1]
if objective_type == 'mass':
if self.analysis_scheme is AnalysisScheme.COLLOCATION:
self.model.add_objective(
f"traj.{final_phase_name}.timeseries.{Dynamic.Vehicle.MASS}",
index=-1,
ref=ref
)
else:
last_phase = self.traj._phases.items()[final_phase_name]
last_phase.add_objective(
Dynamic.Vehicle.MASS, loc='final', ref=ref)
elif objective_type == 'time':
self.model.add_objective(
f"traj.{final_phase_name}.timeseries.time", index=-1, ref=ref)
elif objective_type == "hybrid_objective":
self._add_hybrid_objective(self.phase_info)
self.model.add_objective("obj_comp.obj")
elif objective_type == "fuel_burned":
self.model.add_objective(Mission.Summary.FUEL_BURNED, ref=ref)
elif objective_type == "fuel":
self.model.add_objective(Mission.Objectives.FUEL, ref=ref)
else:
raise ValueError(
f"{objective_type} is not a valid objective.\nobjective_type must"
" be one of mass, time, hybrid_objective, fuel_burned, or fuel")
else: # If no 'objective_type' is specified, we handle based on 'problem_type'
# If 'ref' is not specified, assign a default value
ref = ref if ref is not None else 1
if self.problem_type is ProblemType.SIZING:
self.model.add_objective(Mission.Objectives.FUEL, ref=ref)
elif self.problem_type is ProblemType.ALTERNATE:
self.model.add_objective(Mission.Objectives.FUEL, ref=ref)
elif self.problem_type is ProblemType.FALLOUT:
self.model.add_objective(Mission.Objectives.RANGE, ref=ref)
else:
raise ValueError(f'{self.problem_type} is not a valid problem type.')
def _add_bus_variables_and_connect(self):
all_subsystems = self._get_all_subsystems()
base_phases = list(self.phase_info.keys())
for external_subsystem in all_subsystems:
bus_variables = external_subsystem.get_bus_variables()
if bus_variables is not None:
for bus_variable, variable_data in bus_variables.items():
mission_variable_name = variable_data['mission_name']
# check if mission_variable_name is a list
if not isinstance(mission_variable_name, list):
mission_variable_name = [mission_variable_name]
# loop over the mission_variable_name list and add each variable to
# the trajectory
for mission_var_name in mission_variable_name:
if mission_var_name not in self.meta_data:
# base_units = self.model.get_io_metadata(includes=f'pre_mission.{external_subsystem.name}.{bus_variable}')[f'pre_mission.{external_subsystem.name}.{bus_variable}']['units']
base_units = variable_data['units']
shape = variable_data.get('shape', _unspecified)
targets = mission_var_name
if '.' in mission_var_name:
# Support for non-hierarchy variables as parameters.
mission_var_name = mission_var_name.split('.')[-1]
if 'phases' in variable_data:
# Support for connecting bus variables into a subset of
# phases.
for phase_name in variable_data['phases']:
phase = getattr(self.traj.phases, phase_name)
phase.add_parameter(
mission_var_name, opt=False, static_target=True,
units=base_units, shape=shape, targets=targets)
self.model.connect(
f'pre_mission.{bus_variable}',
f'traj.{phase_name}.parameters:{mission_var_name}')
else:
self.traj.add_parameter(
mission_var_name, opt=False, static_target=True,
units=base_units, shape=shape,
targets={phase_name: [mission_var_name]
for phase_name in base_phases})
self.model.connect(
f'pre_mission.{bus_variable}',
f'traj.parameters:' + mission_var_name)
if 'post_mission_name' in variable_data:
self.model.connect(
f'pre_mission.{external_subsystem.name}.{bus_variable}',
f'post_mission.{external_subsystem.name}.{variable_data["post_mission_name"]}'
)
[docs]
def setup(self, **kwargs):
"""
Lightly wrapped setup() method for the problem.
"""
# suppress warnings:
# "input variable '...' promoted using '*' was already promoted using 'aircraft:*'
with warnings.catch_warnings():
self.model.options['aviary_options'] = self.aviary_inputs
self.model.options['aviary_metadata'] = self.meta_data
self.model.options['phase_info'] = self.phase_info
warnings.simplefilter("ignore", om.OpenMDAOWarning)
warnings.simplefilter("ignore", om.PromotionWarning)
super().setup(**kwargs)
[docs]
def set_initial_guesses(self, parent_prob=None, parent_prefix=""):
"""
Call `set_val` on the trajectory for states and controls to seed
the problem with reasonable initial guesses. This is especially
important for collocation methods.
This method first identifies all phases in the trajectory then
loops over each phase. Specific initial guesses
are added depending on the phase and mission method. Cruise is treated
as a special phase for GASP-based missions because it is an AnalyticPhase
in Dymos. For this phase, we handle the initial guesses first separately
and continue to the next phase after that. For other phases, we set the initial
guesses for states and controls according to the information available
in the 'initial_guesses' attribute of the phase.
"""
setvalprob = self
if parent_prob is not None and parent_prefix != "":
setvalprob = parent_prob
# Grab the trajectory object from the model
if self.analysis_scheme is AnalysisScheme.SHOOTING:
if self.problem_type is ProblemType.SIZING:
setvalprob.set_val(parent_prefix + Mission.Summary.GROSS_MASS,
self.get_val(Mission.Design.GROSS_MASS))
setvalprob.set_val(parent_prefix +
"traj.SGMClimb_" + Dynamic.Mission.ALTITUDE + "_trigger",
val=self.cruise_alt,
units="ft",
)
return
traj = self.model.traj
# Determine which phases to loop over, fetching them from the trajectory
phase_items = traj._phases.items()
# Loop over each phase and set initial guesses for the state and control
# variables
for idx, (phase_name, phase) in enumerate(phase_items):
if self.mission_method is SOLVED_2DOF:
self.phase_objects[idx].apply_initial_guesses(self, 'traj', phase)
if self.phase_info[phase_name]['user_options']['ground_roll'] and self.phase_info[phase_name]['user_options']['fix_initial']:
continue
# If not, fetch the initial guesses specific to the phase
# check if guesses exist for this phase
if "initial_guesses" in self.phase_info[phase_name]:
guesses = self.phase_info[phase_name]['initial_guesses']
else:
guesses = {}
if self.mission_method is TWO_DEGREES_OF_FREEDOM and \
self.phase_info[phase_name]["user_options"].get("analytic", False):
for guess_key, guess_data in guesses.items():
val, units = guess_data
if 'mass' == guess_key:
# Set initial and duration mass for the analytic cruise phase.
# Note we are integrating over mass, not time for this phase.
setvalprob.set_val(
parent_prefix +
f'traj.{phase_name}.t_initial',
val[0],
units=units)
setvalprob.set_val(
parent_prefix +
f'traj.{phase_name}.t_duration',
val[1],
units=units)
else:
# Otherwise, set the value of the parameter in the trajectory
# phase
setvalprob.set_val(
parent_prefix + f'traj.{phase_name}.parameters:{guess_key}',
val, units=units)
continue
# If not cruise and GASP, add subsystem guesses
self._add_subsystem_guesses(phase_name, phase, setvalprob, parent_prefix)
# Set initial guesses for states and controls for each phase
self._add_guesses(phase_name, phase, guesses, setvalprob, parent_prefix)
def _process_guess_var(self, val, key, phase):
"""
Process the guess variable, which can either be a float or an array of floats.
This method is responsible for interpolating initial guesses when the user
provides a list or array of values rather than a single float. It interpolates
the guess values across the phase's domain for a given variable, be it a control
or a state variable. The interpolation is performed between -1 and 1 (representing
the normalized phase time domain), using the numpy linspace function.
The result of this method is a single value or an array of interpolated values
that can be used to seed the optimization problem with initial guesses.
Parameters
----------
val : float or list/array of floats
The initial guess value(s) for a particular variable.
key : str
The key identifying the variable for which the initial guess is provided.
phase : Phase
The phase for which the variable is being set.
Returns
-------
val : float or array of floats
The processed guess value(s) to be used in the optimization problem.
"""
# Check if val is not a single float
if not isinstance(val, float):
# If val is an array of values
if len(val) > 1:
# Get the shape of the val array
shape = np.shape(val)
# Generate an array of evenly spaced values between -1 and 1,
# reshaping to match the shape of the val array
xs = np.linspace(-1, 1, num=np.prod(shape)).reshape(shape)
# Check if the key indicates a control or state variable
if "controls:" in key or "states:" in key:
# If so, strip the first part of the key to match the variable name
# in phase
stripped_key = ":".join(key.split(":")[1:])
# Interpolate the initial guess values across the phase's domain
val = phase.interp(stripped_key, xs=xs, ys=val)
else:
# If not a control or state variable, interpolate the initial guess
# values directly
val = phase.interp(key, xs=xs, ys=val)
# Return the processed guess value(s)
return val
def _add_subsystem_guesses(self, phase_name, phase, setvalprob, parent_prefix):
"""
Adds the initial guesses for each subsystem of a given phase to the problem.
This method first fetches all subsystems associated with the given phase.
It then loops over each subsystem and fetches its initial guesses. For each
guess, it identifies whether the guess corresponds to a state or a control
variable and then processes the guess variable. After this, the initial
guess is set in the problem using the `set_val` method.
Parameters
----------
phase_name : str
The name of the phase for which the subsystem guesses are being added.
phase : Phase
The phase object for which the subsystem guesses are being added.
"""
# Get all subsystems associated with the phase
all_subsystems = self._get_all_subsystems(
self.phase_info[phase_name]['external_subsystems'])
# Loop over each subsystem
for subsystem in all_subsystems:
# Fetch the initial guesses for the subsystem
initial_guesses = subsystem.get_initial_guesses()
# Loop over each guess
for key, val in initial_guesses.items():
# Identify the type of the guess (state or control)
type = val.pop('type')
if 'state' in type:
path_string = 'states'
elif 'control' in type:
path_string = 'controls'
# Process the guess variable (handles array interpolation)
val['val'] = self._process_guess_var(val['val'], key, phase)
# Set the initial guess in the problem
setvalprob.set_val(
parent_prefix + f'traj.{phase_name}.{path_string}:{key}', **val)
def _add_guesses(self, phase_name, phase, guesses, setvalprob, parent_prefix):
"""
Adds the initial guesses for each variable of a given phase to the problem.
This method sets the initial guesses for time, control, state, and problem-specific
variables for a given phase. If using the GASP model, it also handles some special
cases that are not covered in the `phase_info` object. These include initial guesses
for mass, time, and distance, which are determined based on the phase name and other
mission-related variables.
Parameters
----------
phase_name : str
The name of the phase for which the guesses are being added.
phase : Phase
The phase object for which the guesses are being added.
guesses : dict
A dictionary containing the initial guesses for the phase.
"""
# If using the GASP model, set initial guesses for the rotation mass and
# flight duration
if self.mission_method is TWO_DEGREES_OF_FREEDOM:
rotation_mass = self.initialization_guesses['rotation_mass']
flight_duration = self.initialization_guesses['flight_duration']
if self.mission_method in (HEIGHT_ENERGY, SOLVED_2DOF):
control_keys = ["mach", "altitude"]
state_keys = ["mass", Dynamic.Mission.DISTANCE]
else:
control_keys = ["velocity_rate", "throttle"]
state_keys = [
"altitude",
"mass",
Dynamic.Mission.DISTANCE,
Dynamic.Mission.VELOCITY,
"flight_path_angle",
"alpha",
]
if self.mission_method is TWO_DEGREES_OF_FREEDOM and phase_name == 'ascent':
# Alpha is a control for ascent.
control_keys.append('alpha')
prob_keys = ["tau_gear", "tau_flaps"]
# for the simple mission method, use the provided initial and final mach
# and altitude values from phase_info
if self.mission_method in (HEIGHT_ENERGY, SOLVED_2DOF):
initial_altitude = wrapped_convert_units(
self.phase_info[phase_name]['user_options']['initial_altitude'], 'ft')
final_altitude = wrapped_convert_units(
self.phase_info[phase_name]['user_options']['final_altitude'], 'ft')
initial_mach = self.phase_info[phase_name]['user_options']['initial_mach']
final_mach = self.phase_info[phase_name]['user_options']['final_mach']
guesses["mach"] = ([initial_mach[0], final_mach[0]], "unitless")
guesses["altitude"] = ([initial_altitude, final_altitude], 'ft')
if self.mission_method is HEIGHT_ENERGY:
# if time not in initial guesses, set it to the average of the
# initial_bounds and the duration_bounds
if 'time' not in guesses:
initial_bounds = wrapped_convert_units(
self.phase_info[phase_name]['user_options']['initial_bounds'], 's')
duration_bounds = wrapped_convert_units(
self.phase_info[phase_name]['user_options']['duration_bounds'], 's')
guesses["time"] = ([np.mean(initial_bounds[0]), np.mean(
duration_bounds[0])], 's')
# if time not in initial guesses, set it to the average of the
# initial_bounds and the duration_bounds
if 'time' not in guesses:
initial_bounds = self.phase_info[phase_name]['user_options'][
'initial_bounds']
duration_bounds = self.phase_info[phase_name]['user_options'][
'duration_bounds']
# Add a check for the initial and duration bounds, raise an error if they
# are not consistent
if initial_bounds[1] != duration_bounds[1]:
raise ValueError(
f"Initial and duration bounds for {phase_name} are not consistent."
)
guesses["time"] = ([np.mean(initial_bounds[0]), np.mean(
duration_bounds[0])], initial_bounds[1])
for guess_key, guess_data in guesses.items():
val, units = guess_data
# Set initial guess for time variables
if 'time' == guess_key and self.mission_method is not SOLVED_2DOF:
setvalprob.set_val(parent_prefix + f'traj.{phase_name}.t_initial',
val[0], units=units)
setvalprob.set_val(parent_prefix + f'traj.{phase_name}.t_duration',
val[1], units=units)
else:
# Set initial guess for control variables
if guess_key in control_keys:
try:
setvalprob.set_val(
parent_prefix + f'traj.{phase_name}.controls:{guess_key}',
self._process_guess_var(val, guess_key, phase),
units=units)
except KeyError:
try:
setvalprob.set_val(
parent_prefix +
f'traj.{phase_name}.polynomial_controls:{guess_key}',
self._process_guess_var(val, guess_key, phase),
units=units)
except KeyError:
setvalprob.set_val(parent_prefix +
f'traj.{phase_name}.bspline_controls:',
{guess_key},
self._process_guess_var(
val, guess_key, phase),
units=units)
if self.mission_method is SOLVED_2DOF:
continue
if guess_key in control_keys:
pass
# Set initial guess for state variables
elif guess_key in state_keys:
setvalprob.set_val(parent_prefix +
f'traj.{phase_name}.states:{guess_key}', self.
_process_guess_var(val, guess_key, phase),
units=units)
elif guess_key in prob_keys:
setvalprob.set_val(parent_prefix + guess_key, val, units=units)
elif ":" in guess_key:
setvalprob.set_val(
parent_prefix +
f'traj.{phase_name}.{guess_key}',
self._process_guess_var(
val,
guess_key,
phase),
units=units)
else:
# raise error if the guess key is not recognized
raise ValueError(
f"Initial guess key {guess_key} in {phase_name} is not recognized."
)
if self.mission_method is SOLVED_2DOF:
return
# We need some special logic for these following variables because GASP computes
# initial guesses using some knowledge of the mission duration and other variables
# that are only available after calling `create_vehicle`. Thus these initial guess
# values are not included in the `phase_info` object.
if self.mission_method is TWO_DEGREES_OF_FREEDOM:
base_phase = phase_name.removeprefix('reserve_')
else:
base_phase = phase_name
if 'mass' not in guesses:
if self.mission_method is TWO_DEGREES_OF_FREEDOM:
# Determine a mass guess depending on the phase name
if base_phase in ["groundroll", "rotation", "ascent", "accel", "climb1"]:
mass_guess = rotation_mass
elif base_phase == "climb2":
mass_guess = 0.99 * rotation_mass
elif "desc" in base_phase:
mass_guess = 0.9 * self.cruise_mass_final
else:
mass_guess = self.aviary_inputs.get_val(
Mission.Design.GROSS_MASS, units='lbm')
# Set the mass guess as the initial value for the mass state variable
setvalprob.set_val(parent_prefix + f'traj.{phase_name}.states:mass',
mass_guess, units='lbm')
if 'time' not in guesses:
# Determine initial time and duration guesses depending on the phase name
if 'desc1' == base_phase:
t_initial = flight_duration * .9
t_duration = flight_duration * .04
elif 'desc2' in base_phase:
t_initial = flight_duration * .94
t_duration = 5000
# Set the time guesses as the initial values for the time-related
# trajectory variables
setvalprob.set_val(parent_prefix + f"traj.{phase_name}.t_initial",
t_initial, units='s')
setvalprob.set_val(parent_prefix + f"traj.{phase_name}.t_duration",
t_duration, units='s')
if self.mission_method is TWO_DEGREES_OF_FREEDOM:
if 'distance' not in guesses:
# Determine initial distance guesses depending on the phase name
if 'desc1' == base_phase:
ys = [self.target_range * .97, self.target_range * .99]
elif 'desc2' in base_phase:
ys = [self.target_range * .99, self.target_range]
# Set the distance guesses as the initial values for the distance state
# variable
setvalprob.set_val(parent_prefix +
f"traj.{phase_name}.states:distance", phase.interp(
Dynamic.Mission.DISTANCE, ys=ys)
)
[docs]
def run_aviary_problem(self, record_filename="problem_history.db",
optimization_history_filename=None, restart_filename=None,
suppress_solver_print=True, run_driver=True, simulate=False,
make_plots=True):
"""
This function actually runs the Aviary problem, which could be a simulation, optimization, or a driver execution, depending on the arguments provided.
Parameters
----------
record_filename : str, optional
The name of the database file where the solutions are to be recorded. The default is "problem_history.db".
optimization_history_filename : str, None
The name of the database file where the driver iterations are to be recorded. The default is None.
restart_filename : str, optional
The name of the file that contains previously computed solutions which are to be used as starting points for this run. If it is None (default), no restart file will be used.
suppress_solver_print : bool, optional
If True (default), all solvers' print statements will be suppressed. Useful for deeply nested models with multiple solvers so the print statements don't overwhelm the output.
run_driver : bool, optional
If True (default), the driver (aka optimizer) will be executed. If False, the problem will be run through one pass -- equivalent to OpenMDAO's `run_model` behavior.
simulate : bool, optional
If True, an explicit Dymos simulation will be performed. The default is False.
make_plots : bool, optional
If True (default), Dymos html plots will be generated as part of the output.
"""
if self.aviary_inputs.get_val(Settings.VERBOSITY).value >= 2:
self.final_setup()
with open('input_list.txt', 'w') as outfile:
self.model.list_inputs(out_stream=outfile)
if suppress_solver_print:
self.set_solver_print(level=0)
if optimization_history_filename:
recorder = om.SqliteRecorder(optimization_history_filename)
self.driver.add_recorder(recorder)
# and run mission, and dynamics
if run_driver:
failed = dm.run_problem(
self, run_driver=run_driver, simulate=simulate, make_plots=make_plots,
solution_record_file=record_filename, restart=restart_filename)
else:
# prevent UserWarning that is displayed when an event is triggered
warnings.filterwarnings('ignore', category=UserWarning)
failed = self.run_model()
warnings.filterwarnings('default', category=UserWarning)
if self.aviary_inputs.get_val(Settings.VERBOSITY).value >= 2:
with open('output_list.txt', 'w') as outfile:
self.model.list_outputs(out_stream=outfile)
self.problem_ran_successfully = not failed
[docs]
def alternate_mission(self, run_mission=True,
json_filename='sizing_problem.json',
payload_mass=None, mission_range=None,
phase_info=None, verbosity=Verbosity.BRIEF):
"""
This function runs an alternate mission based on a sizing mission output.
Parameters
----------
run_mission : bool
Flag to determine whether to run the mission before returning the problem object.
json_filename : str
Name of the file that the sizing mission has been saved to.
mission_range : float, optional
Target range for the fallout mission.
payload_mass : float, optional
Mass of the payload for the mission.
phase_info : dict, optional
Dictionary containing the phases and their required parameters.
verbosity : Verbosity or list, optional
If Verbosity.DEBUG, debug print options ['desvars','ln_cons','nl_cons','objs'] will be set.
If a list is provided, it will be used as the debug print options.
"""
if phase_info is None:
phase_info = self.phase_info
if mission_range is None:
design_range = self.get_val(Mission.Design.RANGE)
if payload_mass is None:
if self.mission_method is HEIGHT_ENERGY:
payload_mass = self.get_val(Aircraft.CrewPayload.TOTAL_PAYLOAD_MASS)
elif self.mission_method is TWO_DEGREES_OF_FREEDOM:
payload_mass = self.get_val(Aircraft.CrewPayload.PASSENGER_PAYLOAD_MASS)
mission_mass = self.get_val(Mission.Design.GROSS_MASS)
optimizer = self.driver.options["optimizer"]
prob_alternate = _load_off_design(
json_filename,
ProblemType.ALTERNATE,
phase_info,
payload_mass,
design_range,
mission_mass)
prob_alternate.check_and_preprocess_inputs()
prob_alternate.add_pre_mission_systems()
prob_alternate.add_phases()
prob_alternate.add_post_mission_systems()
prob_alternate.link_phases()
prob_alternate.add_driver(optimizer, verbosity=verbosity)
prob_alternate.add_design_variables()
prob_alternate.add_objective()
prob_alternate.setup()
prob_alternate.set_initial_guesses()
if run_mission:
prob_alternate.run_aviary_problem(
record_filename='alternate_problem_history.db')
return prob_alternate
[docs]
def fallout_mission(self, run_mission=True,
json_filename='sizing_problem.json',
mission_mass=None, payload_mass=None,
phase_info=None, verbosity=Verbosity.BRIEF):
"""
This function runs a fallout mission based on a sizing mission output.
Parameters
----------
run_mission : bool
Flag to determine whether to run the mission before returning the problem object.
json_filename : str
Name of the file that the sizing mission has been saved to.
mission_mass : float, optional
Takeoff mass for the fallout mission.
payload_mass : float, optional
Mass of the payload for the mission.
phase_info : dict, optional
Dictionary containing the phases and their required parameters.
verbosity : Verbosity or list, optional
If Verbosity.DEBUG, debug print options ['desvars','ln_cons','nl_cons','objs'] will be set.
If a list is provided, it will be used as the debug print options.
"""
if phase_info is None:
phase_info = self.phase_info
if mission_mass is None:
mission_mass = self.get_val(Mission.Design.GROSS_MASS)
if payload_mass is None:
if self.mission_method is HEIGHT_ENERGY:
payload_mass = self.get_val(Aircraft.CrewPayload.TOTAL_PAYLOAD_MASS)
elif self.mission_method is TWO_DEGREES_OF_FREEDOM:
payload_mass = self.get_val(Aircraft.CrewPayload.PASSENGER_PAYLOAD_MASS)
design_range = self.get_val(Mission.Design.RANGE)
optimizer = self.driver.options["optimizer"]
prob_fallout = _load_off_design(json_filename, ProblemType.FALLOUT, phase_info,
payload_mass, design_range, mission_mass)
prob_fallout.check_and_preprocess_inputs()
prob_fallout.add_pre_mission_systems()
prob_fallout.add_phases()
prob_fallout.add_post_mission_systems()
prob_fallout.link_phases()
prob_fallout.add_driver(optimizer, verbosity=verbosity)
prob_fallout.add_design_variables()
prob_fallout.add_objective()
prob_fallout.setup()
prob_fallout.set_initial_guesses()
if run_mission:
prob_fallout.run_aviary_problem(record_filename='fallout_problem_history.db')
return prob_fallout
[docs]
def save_sizing_to_json(self, json_filename='sizing_problem.json'):
"""
This function saves an aviary problem object into a json file.
Parameters
----------
aviary_problem: OpenMDAO Aviary Problem
Aviary problem object optimized for the aircraft design/sizing mission.
Assumed to contain aviary_inputs and Mission.Summary.GROSS_MASS
json_filename: string
User specified name and relative path of json file to save the data into.
"""
aviary_input_list = []
with open(json_filename, 'w') as jsonfile:
# Loop through aviary input datastructure and create a list
for data in self.aviary_inputs:
(name, (value, units)) = data
type_value = type(value)
# Get the gross mass value from the sizing problem and add it to input
# list
if name == Mission.Summary.GROSS_MASS or name == Mission.Design.GROSS_MASS:
Mission_Summary_GROSS_MASS_val = self.get_val(
Mission.Summary.GROSS_MASS, units=units)
Mission_Summary_GROSS_MASS_val_list = Mission_Summary_GROSS_MASS_val.tolist()
value = Mission_Summary_GROSS_MASS_val_list[0]
else:
# there are different data types we need to handle for conversion to json format
# int, bool, float doesn't need anything special
# Convert numpy arrays to lists
if type_value == np.ndarray:
value = value.tolist()
# Lists are fine except if they contain enums
if type_value == list:
if isinstance(value[0], enum.Enum):
for i in range(len(value)):
value[i] = str([value[i]])
# Enums need converting to a string
if isinstance(value, enum.Enum):
value = str([value])
# Append the data to the list
aviary_input_list.append([name, value, units, str(type_value)])
# Write the list to a json file
json.dump(aviary_input_list, jsonfile, sort_keys=True,
indent=4, ensure_ascii=False)
jsonfile.close()
def _add_hybrid_objective(self, phase_info):
phases = list(phase_info.keys())
takeoff_mass = self.aviary_inputs.get_val(
Mission.Design.GROSS_MASS, units='lbm')
obj_comp = om.ExecComp(f"obj = -final_mass / {takeoff_mass} + final_time / 5.",
final_mass={"units": "lbm"},
final_time={"units": "h"})
self.model.add_subsystem("obj_comp", obj_comp)
final_phase_name = phases[-1]
self.model.connect(f"traj.{final_phase_name}.timeseries.mass",
"obj_comp.final_mass", src_indices=[-1])
self.model.connect(f"traj.{final_phase_name}.timeseries.time",
"obj_comp.final_time", src_indices=[-1])
def _add_vrotate_comp(self):
self.model.add_subsystem("vrot_comp", VRotateComp())
self.model.connect('traj.groundroll.states:mass',
'vrot_comp.mass', src_indices=om.slicer[0, ...])
vrot_eq_comp = self.model.add_subsystem("vrot_eq_comp", om.EQConstraintComp())
vrot_eq_comp.add_eq_output(
"v_rotate_error", eq_units="kn", lhs_name="v_rot_computed",
rhs_name="groundroll_v_final", add_constraint=True)
self.model.connect('vrot_comp.Vrot', 'vrot_eq_comp.v_rot_computed')
self.model.connect(
'traj.groundroll.timeseries.velocity', 'vrot_eq_comp.groundroll_v_final',
src_indices=om.slicer[-1, ...])
def _save_to_csv_file(self, filename):
with open(filename, 'w', newline='') as csvfile:
fieldnames = ['name', 'value', 'units']
writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
for name, value_units in sorted(self.aviary_inputs):
value, units = value_units
writer.writerow({'name': name, 'value': value, 'units': units})
def _get_all_subsystems(self, external_subsystems=None):
all_subsystems = []
if external_subsystems is None:
all_subsystems.extend(self.pre_mission_info['external_subsystems'])
else:
all_subsystems.extend(external_subsystems)
all_subsystems.append(self.core_subsystems['aerodynamics'])
all_subsystems.append(self.core_subsystems['propulsion'])
return all_subsystems
def _add_height_energy_landing_systems(self):
landing_options = Landing(
ref_wing_area=self.aviary_inputs.get_val(
Aircraft.Wing.AREA, units='ft**2'),
Cl_max_ldg=self.aviary_inputs.get_val(
Mission.Landing.LIFT_COEFFICIENT_MAX) # no units
)
landing = landing_options.build_phase(False)
self.model.add_subsystem(
'landing', landing, promotes_inputs=['aircraft:*', 'mission:*'],
promotes_outputs=['mission:*'])
last_flight_phase_name = list(self.phase_info.keys())[-1]
control_type_string = 'control_values'
if self.phase_info[last_flight_phase_name]['user_options'].get(
'use_polynomial_control', True):
if not use_new_dymos_syntax:
control_type_string = 'polynomial_control_values'
last_regular_phase = self.regular_phases[-1]
self.model.connect(f'traj.{last_regular_phase}.states:mass',
Mission.Landing.TOUCHDOWN_MASS, src_indices=[-1])
self.model.connect(f'traj.{last_regular_phase}.{control_type_string}:altitude',
Mission.Landing.INITIAL_ALTITUDE,
src_indices=[0])
def _add_post_mission_takeoff_systems(self):
first_flight_phase_name = list(self.phase_info.keys())[0]
connect_takeoff_to_climb = not self.phase_info[first_flight_phase_name][
'user_options'].get('add_initial_mass_constraint', True)
if connect_takeoff_to_climb:
self.model.connect(Mission.Takeoff.FINAL_MASS,
f'traj.{first_flight_phase_name}.initial_states:mass')
self.model.connect(Mission.Takeoff.GROUND_DISTANCE,
f'traj.{first_flight_phase_name}.initial_states:distance')
control_type_string = 'control_values'
if self.phase_info[first_flight_phase_name]['user_options'].get(
'use_polynomial_control', True):
if not use_new_dymos_syntax:
control_type_string = 'polynomial_control_values'
if self.phase_info[first_flight_phase_name]['user_options'].get(
'optimize_mach', False):
# Create an ExecComp to compute the difference in mach
mach_diff_comp = om.ExecComp(
'mach_resid_for_connecting_takeoff = final_mach - initial_mach')
self.model.add_subsystem('mach_diff_comp', mach_diff_comp)
# Connect the inputs to the mach difference component
self.model.connect(Mission.Takeoff.FINAL_MACH,
'mach_diff_comp.final_mach')
self.model.connect(
f'traj.{first_flight_phase_name}.{control_type_string}:mach',
'mach_diff_comp.initial_mach', src_indices=[0])
# Add constraint for mach difference
self.model.add_constraint(
'mach_diff_comp.mach_resid_for_connecting_takeoff', equals=0.0)
if self.phase_info[first_flight_phase_name]['user_options'].get(
'optimize_altitude', False):
# Similar steps for altitude difference
alt_diff_comp = om.ExecComp(
'altitude_resid_for_connecting_takeoff = final_altitude - initial_altitude', units='ft')
self.model.add_subsystem('alt_diff_comp', alt_diff_comp)
self.model.connect(Mission.Takeoff.FINAL_ALTITUDE,
'alt_diff_comp.final_altitude')
self.model.connect(
f'traj.{first_flight_phase_name}.{control_type_string}:altitude',
'alt_diff_comp.initial_altitude', src_indices=[0])
self.model.add_constraint(
'alt_diff_comp.altitude_resid_for_connecting_takeoff', equals=0.0)
def _add_two_dof_landing_systems(self):
self.model.add_subsystem(
"landing",
LandingSegment(
**(self.ode_args)),
promotes_inputs=['aircraft:*', 'mission:*',
(Dynamic.Vehicle.MASS, Mission.Landing.TOUCHDOWN_MASS)],
promotes_outputs=['mission:*'],
)
self.model.connect(
'pre_mission.interference_independent_of_shielded_area',
'landing.interference_independent_of_shielded_area')
self.model.connect(
'pre_mission.drag_loss_due_to_shielded_wing_area',
'landing.drag_loss_due_to_shielded_wing_area')
def _add_objectives(self):
"add objectives and some constraints"
self.model.add_subsystem(
"fuel_obj",
om.ExecComp(
"reg_objective = overall_fuel/10000 + ascent_duration/30.",
reg_objective={"val": 0.0, "units": "unitless"},
ascent_duration={"units": "s", "shape": 1},
overall_fuel={"units": "lbm"},
),
promotes_inputs=[
("ascent_duration", Mission.Takeoff.ASCENT_DURATION),
("overall_fuel", Mission.Summary.TOTAL_FUEL_MASS),
],
promotes_outputs=[("reg_objective", Mission.Objectives.FUEL)],
)
self.model.add_subsystem(
"range_obj",
om.ExecComp(
"reg_objective = -actual_range/1000 + ascent_duration/30.",
reg_objective={"val": 0.0, "units": "unitless"},
ascent_duration={"units": "s", "shape": 1},
actual_range={
"val": self.target_range, "units": "NM"},
),
promotes_inputs=[
"actual_range",
("ascent_duration", Mission.Takeoff.ASCENT_DURATION),
],
promotes_outputs=[("reg_objective", Mission.Objectives.RANGE)],
)
if self.analysis_scheme is AnalysisScheme.COLLOCATION:
if self.mission_method is TWO_DEGREES_OF_FREEDOM:
ascent_phase = getattr(self.traj.phases, 'ascent')
ascent_tx = ascent_phase.options["transcription"]
ascent_num_nodes = ascent_tx.grid_data.num_nodes
self.model.add_subsystem(
"h_fit",
PolynomialFit(N_cp=ascent_num_nodes),
promotes_inputs=["t_init_gear", "t_init_flaps"],
)
self.model.add_subsystem(
"range_constraint",
om.ExecComp(
"range_resid = target_range - actual_range",
target_range={"val": self.target_range, "units": "NM"},
actual_range={"val": self.target_range, "units": "NM"},
range_resid={"val": 30, "units": "NM"},
),
promotes_inputs=[
"actual_range",
("target_range", Mission.Summary.RANGE),
],
promotes_outputs=[
("range_resid", Mission.Constraints.RANGE_RESIDUAL)],
)
def _add_fuel_reserve_component(self, post_mission=True,
reserves_name=Mission.Design.RESERVE_FUEL):
if post_mission:
reserve_calc_location = self.post_mission
else:
reserve_calc_location = self.model
RESERVE_FUEL_FRACTION = self.aviary_inputs.get_val(
Aircraft.Design.RESERVE_FUEL_FRACTION, units='unitless')
if RESERVE_FUEL_FRACTION != 0:
reserve_fuel_frac = om.ExecComp(
'reserve_fuel_frac_mass = reserve_fuel_fraction * (takeoff_mass - final_mass)',
reserve_fuel_frac_mass={
"units": "lbm"},
reserve_fuel_fraction={
"units": "unitless",
"val": RESERVE_FUEL_FRACTION},
final_mass={
"units": "lbm"},
takeoff_mass={
"units": "lbm"})
reserve_calc_location.add_subsystem(
"reserve_fuel_frac", reserve_fuel_frac,
promotes_inputs=[("takeoff_mass", Mission.Summary.GROSS_MASS),
("final_mass", Mission.Landing.TOUCHDOWN_MASS),
("reserve_fuel_fraction", Aircraft.Design.
RESERVE_FUEL_FRACTION)],
promotes_outputs=["reserve_fuel_frac_mass"])
RESERVE_FUEL_ADDITIONAL = self.aviary_inputs.get_val(
Aircraft.Design.RESERVE_FUEL_ADDITIONAL, units='lbm')
reserve_fuel = om.ExecComp(
'reserve_fuel = reserve_fuel_frac_mass + reserve_fuel_additional + reserve_fuel_burned',
reserve_fuel={"units": "lbm", 'shape': 1},
reserve_fuel_frac_mass={"units": "lbm", "val": 0},
reserve_fuel_additional={"units": "lbm", "val": RESERVE_FUEL_ADDITIONAL},
reserve_fuel_burned={"units": "lbm", "val": 0})
reserve_calc_location.add_subsystem(
"reserve_fuel",
reserve_fuel,
promotes_inputs=[
"reserve_fuel_frac_mass",
("reserve_fuel_additional",
Aircraft.Design.RESERVE_FUEL_ADDITIONAL),
("reserve_fuel_burned",
Mission.Summary.RESERVE_FUEL_BURNED)],
promotes_outputs=[
("reserve_fuel",
reserves_name)])
def _read_sizing_json(aviary_problem, json_filename):
"""
This function reads in an aviary problem object from a json file.
Parameters
----------
aviary_problem: OpenMDAO Aviary Problem
Aviary problem object optimized for the aircraft design/sizing mission.
Assumed to contain aviary_inputs and Mission.Summary.GROSS_MASS
json_filename: string
User specified name and relative path of json file to save the data into
Returns
----------
Aviary Problem object with updated input values from json file
"""
# load saved input list from json file
with open(json_filename) as json_data_file:
loaded_aviary_input_list = json.load(json_data_file)
json_data_file.close()
# Loop over input list and assign aviary problem input values
counter = 0 # list index tracker
for inputs in loaded_aviary_input_list:
[var_name, var_values, var_units, var_type] = inputs
# Initialize some flags to idetify arrays and enums
is_array = False
is_enum = False
if var_type == "<class 'numpy.ndarray'>":
is_array = True
elif var_type == "<class 'list'>":
# check if the list contains enums
for i in range(len(var_values)):
if isinstance(var_values[i], str):
if var_values[i].find("<") != -1:
# Found a list of enums: set the flag
is_enum = True
# Manipulate the string to find the value
tmp_var_values = var_values[i].split(':')[-1]
var_values[i] = tmp_var_values.replace(">", "").replace(
"]", "").replace("'", "").replace(" ", "")
if is_enum:
var_values = convert_strings_to_data(var_values)
else:
var_values = [var_values]
elif var_type.find("<enum") != -1:
# Identify enums and manipulate the string to find the value
tmp_var_values = var_values.split(':')[-1]
var_values = tmp_var_values.replace(">", "").replace(
"]", "").replace("'", "").replace(" ", "")
var_values = convert_strings_to_data([var_values])
else:
# values are expected to be parsed as a list to set_value function
var_values = [var_values]
# Check if the variable is in meta data
if var_name in BaseMetaData.keys():
try:
aviary_problem.aviary_inputs = set_value(
var_name, var_values, aviary_problem.aviary_inputs, units=var_units,
is_array=is_array, meta_data=BaseMetaData)
except BaseException:
# Print helpful error
print(
"FAILURE: list_num = ",
counter,
"Input String = ",
inputs,
"Attempted to set_value(",
var_name,
",",
var_values,
",",
var_units,
")")
else:
# Not in the MetaData
print(
"Name not found in MetaData: list_num =",
counter,
"Input String =",
inputs,
"Attempted set_value(",
var_name,
",",
var_values,
",",
var_units,
")")
counter = counter + 1 # increment index tracker
return aviary_problem
def _load_off_design(json_filename, ProblemType, phase_info,
payload, mission_range, mission_gross_mass):
"""
This function loads a sized aircraft, and sets up an aviary problem
for a specified off design mission.
Parameters
----------
json_filename: string
User specified name and relative path of json file containing the sized aircraft data
ProblemType: enum
Alternate or Fallout. Alternate requires mission_range input and
Fallout requires mission_fuel input
phase_info: phase_info dictionary for off design mission
payload: float
Aircraft.CrewPayload.PASSENGER_PAYLOAD_MASS
mission_range float
Mission.Summary.RANGE 'NM'
mission_gross_mass float
Mission.Summary.GROSS_MASS 'lbm'
Returns
----------
Aviary Problem object with completed load_inputs() for specified off design mission
"""
# Initialize a new aviary problem and aviary_input data structure
prob = AviaryProblem()
prob.aviary_inputs = AviaryValues()
prob = _read_sizing_json(prob, json_filename)
# Update problem type
prob.problem_type = ProblemType
prob.aviary_inputs.set_val('settings:problem_type', ProblemType, units='unitless')
# Set Payload
prob.aviary_inputs.set_val(
Aircraft.CrewPayload.PASSENGER_PAYLOAD_MASS, payload, units='lbm')
if ProblemType == ProblemType.ALTERNATE:
# Set mission range, aviary will calculate required fuel
prob.aviary_inputs.set_val(Mission.Design.RANGE, mission_range, units='NM')
elif ProblemType == ProblemType.FALLOUT:
# Set mission fuel and calculate gross weight, aviary will calculate range
prob.aviary_inputs.set_val(Mission.Summary.GROSS_MASS,
mission_gross_mass, units='lbm')
# Load inputs
prob.load_inputs(prob.aviary_inputs, phase_info)
return prob
