# -*- coding: utf-8 -*-
#
# Copyright 2015-2019 European Commission (JRC);
# Licensed under the EUPL (the 'Licence');
# You may not use this work except in compliance with the Licence.
# You may obtain a copy of the Licence at: http://ec.europa.eu/idabc/eupl
"""
Functions and `dsp` model to model torque losses and temperature of gearbox.
"""
import math
import schedula as sh
from co2mpas.defaults import dfl
dsp = sh.BlueDispatcher(
name='Gear box thermal sub model',
description='Calculates temperature, efficiency, torque loss of gear box.'
)
[docs]@sh.add_function(dsp, outputs=['gear_box_torque'])
def calculate_gear_box_torque(
gear_box_power_out, gear_box_speed_out, gear_box_speed_in,
min_engine_on_speed):
"""
Calculates torque entering the gear box [N*m].
:param gear_box_power_out:
Power at wheels [kW].
:type gear_box_power_out: float
:param gear_box_speed_in:
Engine speed [RPM].
:type gear_box_speed_in: float
:param gear_box_speed_out:
Wheel speed [RPM].
:type gear_box_speed_out: float
:param min_engine_on_speed:
Minimum engine speed to consider the engine to be on [RPM].
:type min_engine_on_speed: float
:return:
Torque gear box vector [N*m].
:rtype: numpy.array | float
.. note:: Torque entering the gearbox can be from engine side
(power mode or from wheels in motoring mode)
"""
if gear_box_power_out > 0:
x = gear_box_speed_in
else:
x = gear_box_speed_out
if x <= min_engine_on_speed:
return 0
return gear_box_power_out / x * 30000.0 / math.pi
dsp.add_data(
data_id='gear_box_temperature_references',
default_value=dfl.values.gear_box_temperature_references
)
def _evaluate_gear_box_torque_in(
min_engine_on_speed, gear_box_torque, gear_box_speed_in,
gear_box_speed_out, gear_box_efficiency_parameters):
"""
Calculates torque required according to the temperature profile [N*m].
"""
tgb, es, ws = gear_box_torque, gear_box_speed_in, gear_box_speed_out
par = gear_box_efficiency_parameters
if tgb < 0 < es and ws > 0:
return (par['gbp01'] * tgb - par['gbp10'] * ws - par['gbp00']) * ws / es
elif es > min_engine_on_speed and ws > min_engine_on_speed:
return (tgb - par['gbp10'] * es - par['gbp00']) / par['gbp01']
return 0
# noinspection PyPep8Naming
[docs]@sh.add_function(dsp, outputs=['gear_box_torque_in<0>'])
def calculate_gear_box_torque_in(
gear_box_torque, gear_box_speed_in, gear_box_speed_out,
gear_box_temperature, gear_box_efficiency_parameters_cold_hot,
gear_box_temperature_references, min_engine_on_speed):
"""
Calculates torque required according to the temperature profile [N*m].
:param gear_box_torque:
Torque gear box [N*m].
:type gear_box_torque: float
:param gear_box_speed_in:
Engine speed [RPM].
:type gear_box_speed_in: float
:param gear_box_speed_out:
Wheel speed [RPM].
:type gear_box_speed_out: float
:param gear_box_temperature:
Gear box temperature [°C].
:type gear_box_temperature: float
:param gear_box_efficiency_parameters_cold_hot:
Parameters of gear box efficiency model for cold/hot phases:
- 'hot': `gbp00`, `gbp10`, `gbp01`
- 'cold': `gbp00`, `gbp10`, `gbp01`
:type gear_box_efficiency_parameters_cold_hot: dict
:param gear_box_temperature_references:
Cold and hot reference temperatures [°C].
:type gear_box_temperature_references: tuple
:param min_engine_on_speed:
Minimum engine speed to consider the engine to be on [RPM].
:type min_engine_on_speed: float
:return:
Torque required according to the temperature profile [N*m].
:rtype: float
"""
par = gear_box_efficiency_parameters_cold_hot
T_cold, T_hot = gear_box_temperature_references
t_out = gear_box_torque
min_es = min_engine_on_speed
e_s, gb_s = gear_box_speed_in, gear_box_speed_out
t = _evaluate_gear_box_torque_in(min_es, t_out, e_s, gb_s, par['hot'])
if not T_cold == T_hot and gear_box_temperature <= T_hot:
t_cold = _evaluate_gear_box_torque_in(
min_es, t_out, e_s, gb_s, par['cold']
)
t += (T_hot - gear_box_temperature) / (T_hot - T_cold) * (t_cold - t)
return t
[docs]@sh.add_function(
dsp,
inputs=['gear_box_torque', 'gear_box_torque_in<0>', 'gear',
'gear_box_ratios'],
outputs=['gear_box_torque_in']
)
def correct_gear_box_torque_in(
gear_box_torque, gear_box_torque_in, gear, gear_box_ratios):
"""
Corrects the torque when the gear box ratio is equal to 1.
:param gear_box_torque:
Torque gear_box [N*m].
:type gear_box_torque: float
:param gear_box_torque_in:
Torque required [N*m].
:type gear_box_torque_in: float
:param gear:
Gear [-].
:type gear: int
:param gear_box_ratios:
Gear box ratios [-].
:type gear_box_ratios: dict[int, float | int]
:return:
Corrected torque required [N*m].
:rtype: float
"""
gbr = gear_box_ratios
if gbr is None or gear is None:
return gear_box_torque_in
return gear_box_torque if gbr.get(gear, 0) == 1 else gear_box_torque_in
[docs]@sh.add_function(dsp, outputs=['gear_box_efficiency'])
def calculate_gear_box_efficiency(
gear_box_power_out, gear_box_speed_in, gear_box_torque,
gear_box_torque_in, min_engine_on_speed):
"""
Calculates the gear box efficiency [N*m].
:param gear_box_power_out:
Power at wheels [kW].
:type gear_box_power_out: float
:param gear_box_speed_in:
Engine speed [RPM].
:type gear_box_speed_in: float
:param gear_box_torque:
Torque gear_box [N*m].
:type gear_box_torque: float
:param gear_box_torque_in:
Torque required [N*m].
:type gear_box_torque_in: float
:param min_engine_on_speed:
Minimum engine speed to consider the engine to be on [RPM].
:type min_engine_on_speed: float
:return:
Gear box efficiency [-].
:rtype: float
"""
if gear_box_torque_in == gear_box_torque or gear_box_power_out == 0 or \
gear_box_speed_in < min_engine_on_speed:
eff = 1
else:
s_in = gear_box_speed_in
eff = s_in * gear_box_torque_in / gear_box_power_out * (math.pi / 30000)
if gear_box_power_out > 0:
eff = 1 / eff if eff else 1
return max(0, min(1, eff))
[docs]@sh.add_function(dsp, outputs=['gear_box_heat'])
def calculate_gear_box_heat(
gear_box_efficiency, gear_box_power_out, delta_time):
"""
Calculates the gear box temperature heat [W].
:param gear_box_efficiency:
Gear box efficiency [-].
:type gear_box_efficiency: float
:param gear_box_power_out:
Power at wheels [kW].
:type gear_box_power_out: float
:param delta_time:
Time step [s].
:type delta_time: float
:return:
Gear box heat [W].
:rtype: float
"""
if gear_box_efficiency and gear_box_power_out:
eff = gear_box_efficiency
return abs(gear_box_power_out) * (1.0 - eff) * 1000.0 * delta_time
return 0.0
[docs]@sh.add_function(dsp, outputs=['gear_box_temperature'])
def calculate_next_gear_box_temperature(
gear_box_heat, gear_box_temperature, equivalent_gear_box_heat_capacity):
"""
Calculates the gear box temperature not finalized [°C].
:param gear_box_heat:
Gear box heat [W].
:type gear_box_heat: float
:param gear_box_temperature:
Starting gear box temperature not finalized [°C].
:type gear_box_temperature: float
:param equivalent_gear_box_heat_capacity:
Equivalent gear box capacity (from cold start model) [W/°C].
:type equivalent_gear_box_heat_capacity: float
:return:
Gear box temperature not finalized [°C].
:rtype: float
"""
dtemp = gear_box_heat / equivalent_gear_box_heat_capacity
return gear_box_temperature + dtemp
def _thermal(
gear_box_temperature, gear_box_torque, gear, delta_time,
gear_box_power_out, gear_box_speed_out, gear_box_speed_in,
equivalent_gear_box_heat_capacity,
gear_box_efficiency_parameters_cold_hot,
gear_box_temperature_references, gear_box_ratios=None,
min_engine_on_speed=None):
if gear_box_torque is None:
gear_box_torque = calculate_gear_box_torque(
gear_box_power_out, gear_box_speed_out, gear_box_speed_in,
min_engine_on_speed
)
gear_box_torque_in = calculate_gear_box_torque_in(
gear_box_torque, gear_box_speed_in, gear_box_speed_out,
gear_box_temperature, gear_box_efficiency_parameters_cold_hot,
gear_box_temperature_references, min_engine_on_speed
)
gear_box_torque_in = correct_gear_box_torque_in(
gear_box_torque, gear_box_torque_in, gear, gear_box_ratios
)
gear_box_efficiency = calculate_gear_box_efficiency(
gear_box_power_out, gear_box_speed_in, gear_box_torque,
gear_box_torque_in, min_engine_on_speed
)
gear_box_heat = calculate_gear_box_heat(
gear_box_efficiency, gear_box_power_out, delta_time
)
gear_box_temperature = calculate_next_gear_box_temperature(
gear_box_heat, gear_box_temperature, equivalent_gear_box_heat_capacity
)
return gear_box_temperature, gear_box_torque_in, gear_box_efficiency
