"""
Estimation of payload center(s) of gravity.
"""
# This file is part of FAST-OAD_CS23 : A framework for rapid Overall Aircraft Design
# Copyright (C) 2022 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.core.explicitcomponent import ExplicitComponent
from .constants import SUBMODEL_PAYLOAD_CG
[docs]@oad.RegisterSubmodel(SUBMODEL_PAYLOAD_CG, "fastga.submodel.weight.cg.payload.legacy")
class ComputePayloadCG(ExplicitComponent):
# TODO: Document equations. Cite sources
"""Payload center(s) of gravity estimation"""
[docs] def setup(self):
self.add_input("data:geometry:fuselage:front_length", val=np.nan, units="m")
self.add_input("data:weight:furniture:passenger_seats:CG:x", val=np.nan, units="m")
self.add_input("data:geometry:fuselage:PAX_length", val=np.nan, units="m")
self.add_input("data:geometry:fuselage:luggage_length", val=np.nan, units="m")
self.add_output("data:weight:payload:PAX:CG:x", units="m")
self.add_output("data:weight:payload:rear_fret:CG:x", units="m")
self.add_output("data:weight:payload:front_fret:CG:x", units="m")
self.declare_partials("*", "*", method="fd")
[docs] def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
lav = inputs["data:geometry:fuselage:front_length"]
x_cg_d2 = inputs["data:weight:furniture:passenger_seats:CG:x"]
lpax = inputs["data:geometry:fuselage:PAX_length"]
l_lug = inputs["data:geometry:fuselage:luggage_length"]
# Passengers gravity center identical to seats
x_cg_pax = x_cg_d2
# Instruments length
l_instr = 0.7
# Fret center of gravity
x_cg_f_fret = lav * 0.0 # ???: should be defined somewhere in the CAB
x_cg_r_fret = lav + l_instr + lpax + l_lug / 2
outputs["data:weight:payload:PAX:CG:x"] = x_cg_pax
outputs["data:weight:payload:rear_fret:CG:x"] = x_cg_r_fret
outputs["data:weight:payload:front_fret:CG:x"] = x_cg_f_fret