"""
Python module for payload mass estimation, part of the mass breakdown computation.
"""
# This file is part of FAST-OAD_CS23 : A framework for rapid Overall Aircraft Design
# Copyright (C) 2025 ONERA & ISAE-SUPAERO
# FAST is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
import fastoad.api as oad
import numpy as np
from openmdao import api as om
from .constants import SERVICE_PAYLOAD_MASS, SUBMODEL_PAYLOAD_MASS_LEGACY
[docs]@oad.RegisterSubmodel(SERVICE_PAYLOAD_MASS, SUBMODEL_PAYLOAD_MASS_LEGACY)
class ComputePayload(om.ExplicitComponent):
"""Computes payload from NPAX."""
# pylint: disable=missing-function-docstring
# Overriding OpenMDAO setup
[docs] def setup(self):
self.add_input("data:TLAR:NPAX_design", val=np.nan)
self.add_input("data:geometry:cabin:seats:passenger:NPAX_max", val=np.nan)
self.add_input("data:geometry:cabin:luggage:mass_max", val=np.nan, units="kg")
self.add_input("data:TLAR:luggage_mass_design", val=np.nan, units="kg")
self.add_input(
"settings:weight:aircraft:payload:design_mass_per_passenger",
val=80.0,
units="kg",
desc="Design value of mass per passenger",
)
self.add_input(
"settings:weight:aircraft:payload:max_mass_per_passenger",
val=90.0,
units="kg",
desc="Maximum value of mass per passenger",
)
self.add_output("data:weight:aircraft:payload", units="kg")
self.add_output("data:weight:aircraft:max_payload", units="kg")
self.declare_partials(
"data:weight:aircraft:payload",
[
"data:TLAR:NPAX_design",
"settings:weight:aircraft:payload:design_mass_per_passenger",
],
method="exact",
)
self.declare_partials(
"data:weight:aircraft:payload", "data:TLAR:luggage_mass_design", val=1.0
)
self.declare_partials(
"data:weight:aircraft:max_payload",
[
"data:geometry:cabin:seats:passenger:NPAX_max",
"settings:weight:aircraft:payload:max_mass_per_passenger",
"data:geometry:cabin:luggage:mass_max",
],
method="exact",
)
self.declare_partials(
"data:weight:aircraft:max_payload", "data:geometry:cabin:luggage:mass_max", val=1.0
)
# pylint: disable=missing-function-docstring, unused-argument
# Overriding OpenMDAO compute, not all arguments are used
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
npax_design = inputs["data:TLAR:NPAX_design"] + 2.0 # addition of 2 pilots
npax_max = (
inputs["data:geometry:cabin:seats:passenger:NPAX_max"] + 2.0
) # addition of 2 pilots
mass_per_pax = inputs["settings:weight:aircraft:payload:design_mass_per_passenger"]
max_mass_per_pax = inputs["settings:weight:aircraft:payload:max_mass_per_passenger"]
luggage_mass_design = inputs["data:TLAR:luggage_mass_design"]
luggage_mass_max = inputs["data:geometry:cabin:luggage:mass_max"]
outputs["data:weight:aircraft:payload"] = npax_design * mass_per_pax + luggage_mass_design
outputs["data:weight:aircraft:max_payload"] = npax_max * max_mass_per_pax + luggage_mass_max
# pylint: disable=missing-function-docstring, unused-argument
# Overriding OpenMDAO compute_partials, not all arguments are used
[docs] def compute_partials(self, inputs, partials, discrete_inputs=None):
partials[
"data:weight:aircraft:payload",
"settings:weight:aircraft:payload:design_mass_per_passenger",
] = inputs["data:TLAR:NPAX_design"] + 2.0
partials["data:weight:aircraft:payload", "data:TLAR:NPAX_design"] = inputs[
"settings:weight:aircraft:payload:design_mass_per_passenger"
]
partials[
"data:weight:aircraft:max_payload", "data:geometry:cabin:seats:passenger:NPAX_max"
] = inputs["settings:weight:aircraft:payload:max_mass_per_passenger"]
partials[
"data:weight:aircraft:max_payload",
"settings:weight:aircraft:payload:max_mass_per_passenger",
] = inputs["data:geometry:cabin:seats:passenger:NPAX_max"] + 2.0