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python - 隐式组件：设置初始参数值

问题描述

使用OpenMDAO v1.7.3 Alpha

我有一个由 2 个隐式组件组成的简单示例 OpenMDAO 问题：

  1. 第一个组件使用温度计算电压
  2. 第二个组件使用电压来计算温度

（问题底部的代码）

不幸的是，当我在 OpenMDAO 中运行它时，它无法收敛。我认为问题在于我没有设置初始参数值。由于 OpenMDAO 正在打印以下消息以输出：

以下参数连接到无序更新的未知数，因此它们的初始值可能包含未初始化的未知值：['battery_temp_comp.volt']

我一直在搜索文档，但无法弄清楚如何正确设置此类问题（使用隐式组件）。任何帮助表示赞赏。谢谢！

代码：

from __future__ import print_function
import math as m
import numpy

from openmdao.api import Component, Group, Problem, Newton, ScipyGMRES


class BatteryVoltImplicitComp(Component):
    """ A Simple Implicit Component modelling a Battery's Voltage"""
    def __init__(self):
        super(BatteryVoltImplicitComp, self).__init__()

        # Params
        self.add_param('temp', 30.0)

        # Unknowns
        self.add_output('volt', 12.0)

        # States
        self.add_state('delta', 0.0)

    def calc_voltage(self, params, unknowns, resids):
        temp = params['temp']
        voltage_shift = (25.667 - temp) * 0.02933
        return 12.77 + voltage_shift

    def solve_nonlinear(self, params, unknowns, resids):
        pass

    def apply_nonlinear(self, params, unknowns, resids):
        print("Params:   BatteryVoltImplicitComp.temp: {}".format(params['temp']))
        print("Unknowns: BatteryVoltImplicitComp.volt: {}".format(unknowns['volt']))
        print("Resids: BatteryVoltImplicitComp.delta: {}".format(resids['delta']))
        calculated_voltage = self.calc_voltage(params, unknowns, resids)

        resids['delta'] = calculated_voltage - unknowns['volt']


class BatteryTempImplicitComp(Component):
    """ A Simple Implicit Component modelling a Battery's Temperature"""
    def __init__(self):
        super(BatteryTempImplicitComp, self).__init__()

        # Params
        self.add_param('volt', 12.0)
        # Unknowns
        self.add_output('temp', 30.0)

        # States
        self.add_state('delta', 0.0)

    def calc_temp(self, params, unknowns, resids):
        v = params['volt']
        room_temp = 23.0            # celsius
        batt_resist = 50e-3
        power = v**2 / batt_resist
        temp_increase = power / 50  # magic number
        return room_temp + temp_increase

    def solve_nonlinear(self, params, unknowns, resids):
        pass

    def apply_nonlinear(self, params, unknowns, resids):
        print("Params:   BatteryTempImplicitComp.volt: {}".format(params['volt']))
        print("Unknowns: BatteryTempImplicitComp.temp: {}".format(unknowns['temp']))
        print("Resids: BatteryTempImplicitComp.delta: {}".format(resids['delta']))
        calculated_temp = self.calc_temp(params, unknowns, resids)

        resids['delta'] = calculated_temp - unknowns['temp']


if __name__ == '__main__':

    top = Problem()
    root = top.root = Group()

    root.add('battery_temp_comp', BatteryTempImplicitComp())
    root.add('battery_volt_comp', BatteryVoltImplicitComp())

    root.connect('battery_volt_comp.volt', 'battery_temp_comp.volt')
    root.connect('battery_temp_comp.temp', 'battery_volt_comp.temp')
    root.battery_temp_comp.deriv_options['type'] = 'fd'
    root.battery_temp_comp.deriv_options['form'] = 'central'
    root.battery_temp_comp.deriv_options['step_size'] = 1.0e-1
    root.battery_volt_comp.deriv_options['type'] = 'fd'
    root.battery_volt_comp.deriv_options['form'] = 'central'
    root.battery_volt_comp.deriv_options['step_size'] = 1.0e-1

    root.nl_solver = Newton()
    root.ln_solver = ScipyGMRES()

    top.setup()
    top.run()

    print('Solution (battery_volt_comp): volt = {}, temp = {}, resid = {}'.format(top['battery_volt_comp.volt'], top['battery_volt_comp.temp'], top['battery_volt_comp.delta']))
    print('Solution (battery_temp_comp): volt = {}, temp = {}, resid = {}'.format(top['battery_temp_comp.volt'], top['battery_temp_comp.temp'], top['battery_temp_comp.delta']))

输出：

#######################################

设置：检查根问题是否存在潜在问题...

没有指定记录器，因此不会保存数据。组 '' 具有以下周期： [['battery_temp_comp', 'battery_volt_comp']]

以下参数连接到无序更新的未知数，因此它们的初始值可能包含未初始化的未知值：['battery_temp_comp.volt']

设置：根问题检查完成。

#######################################

参数： BatteryTempImplicitComp.volt：12.0
未知：BatteryTempImplicitComp.temp：30.0 残差：BatteryTempImplicitComp.delta
：0.0
参数：BatteryVoltImplicitComp.temp：30.0
未知：BatteryVoltImplicitComp.volt：12.0
残差：BatteryVoltImplicitComp.delta：0.0
参数：BatteryTempImplicitComp.volt：12.1
未知：BatteryTempImplicitComp.temp：30.0
残差：BatteryTempImplicitComp.delta：50.6
参数：BatteryTempImplicitComp.volt：11.9
未知数：BatteryTempImplicitComp.temp：30.0
残差：BatteryTempImplicitComp.delta：50.6
参数：BatteryTempImplicitComp.volt：12.0
未知数：BatteryTempImplicitComp.temp：30.0
残差： BatteryTempImplicitComp.delta ：50.6 参数：
BatteryTempImplicitComp.volt ：12.0 未知数：BatteryTempImplicitComp.temp：
30.0残差：BatteryTempImplicitComp.delta
：50.6
参数：BatteryVoltImplicitComp.temp：30.1
未知数：BatteryVoltImplicitComp.volt：12.0
残差：BatteryVolt291311
参数：0.6 ：BatteryVoltImplicitComp.temp：29.9
未知数：BatteryVoltImplicitComp.volt：12.0
Resids：BatteryVoltImplicitComp.delta：0.64291311

...

参数：BatteryVoltImplicitComp.temp：nan
未知数：BatteryVoltImplicitComp.volt：nan
Resids：BatteryVoltImplicitComp.delta：0.64291311
[root] NL：NEWTON 1 | 1 次迭代后无法收敛
解决方案 (battery_volt_comp): volt = nan, temp = nan, resid = -inf
解决方案 (battery_temp_comp): volt = nan, temp = nan, resid = -inf

标签： pythonopenmdao

解决方案

我解决了这个问题。代替

# Params
self.add_param('temp', 30.0)
# Unknowns
self.add_output('volt', 12.0)
# States
self.add_state('delta', 0.0)
...
resids['delta'] = calculated_temp - unknowns['temp']

我需要这样做：

# Params
self.add_param('temp', 30.0)
# Unknowns / Residuals
self.add_state('volt', 12.0)
...
resids['volt'] = calculated_voltage - unknowns['volt']

不幸的是，当我在 OpenMDAO 中运行它时，它无法收敛。我认为问题在于我没有设置初始参数值。

虽然初始参数值不是我的问题的原因，但设置初始值的最简单方法是：

top.setup()
top['battery_temp_comp.temp'] = 23.0
top.run()

第一次执行的顺序由connect语句的顺序决定。Group.list_order()将打印出组内组件的执行顺序。

代码：

from __future__ import print_function

from openmdao.api import Component, Group, Problem, Newton, ScipyGMRES


class BatteryVoltImplicitComp(Component):
    """ A Simple Implicit Component modeling a Battery's Voltage"""
    def __init__(self):
        super(BatteryVoltImplicitComp, self).__init__()

        # Params
        self.add_param('temp', 30.0)

        # Unknowns / Residuals
        self.add_state('volt', 12.0)

    def calc_voltage(self, params, unknowns, resids):
        temp = params['temp']
        voltage_shift = (25.667 - temp) * 0.02933
        return 12.77 + voltage_shift

    def solve_nonlinear(self, params, unknowns, resids):
        pass

    def apply_nonlinear(self, params, unknowns, resids):
        print("Params:   BatteryVoltImplicitComp.temp: {}".format(params['temp']))
        print("Unknowns: BatteryVoltImplicitComp.volt: {}".format(unknowns['volt']))
        print("Resids: BatteryVoltImplicitComp.volt: {}".format(resids['volt']))
        calculated_voltage = self.calc_voltage(params, unknowns, resids)

        resids['volt'] = calculated_voltage - unknowns['volt']


class BatteryTempImplicitComp(Component):
    """ A Simple Implicit Component modeling a Battery's Temperature"""
    def __init__(self):
        super(BatteryTempImplicitComp, self).__init__()

        # Params
        self.add_param('volt', 12.0)

        # Unknowns / Residuals
        self.add_state('temp', 30.0)

    def calc_temp(self, params, unknowns, resids):
        v = params['volt']
        room_temp = 23.0            # celsius
        batt_resist = 50e-3
        power = v**2 / batt_resist
        temp_increase = power / 50  # magic number
        return room_temp + temp_increase

    def solve_nonlinear(self, params, unknowns, resids):
        pass

    def apply_nonlinear(self, params, unknowns, resids):
        print("Params:   BatteryTempImplicitComp.volt: {}".format(params['volt']))
        print("Unknowns: BatteryTempImplicitComp.temp: {}".format(unknowns['temp']))
        print("Resids: BatteryTempImplicitComp.temp: {}".format(resids['temp']))
        calculated_temp = self.calc_temp(params, unknowns, resids)

        resids['temp'] = calculated_temp - unknowns['temp']


if __name__ == '__main__':

    top = Problem()
    root = top.root = Group()

    root.add('battery_volt_comp', BatteryVoltImplicitComp())
    root.add('battery_temp_comp', BatteryTempImplicitComp())

    root.connect('battery_volt_comp.volt', 'battery_temp_comp.volt')
    root.connect('battery_temp_comp.temp', 'battery_volt_comp.temp')
    root.battery_temp_comp.deriv_options['type'] = 'fd'
    root.battery_temp_comp.deriv_options['form'] = 'central'
    root.battery_temp_comp.deriv_options['step_size'] = 1.0e-4
    root.battery_volt_comp.deriv_options['type'] = 'fd'
    root.battery_volt_comp.deriv_options['form'] = 'central'
    root.battery_volt_comp.deriv_options['step_size'] = 1.0e-4

    root.nl_solver = Newton()
    root.ln_solver = ScipyGMRES()
    top.setup()
    top['battery_temp_comp.temp'] = 23.0
    top.run()

    print('Solution (battery_volt_comp): volt = {}, temp = {}'.format(top['battery_volt_comp.volt'], top['battery_volt_comp.temp']))
    print('Solution (battery_temp_comp): volt = {}, temp = {}'.format(top['battery_temp_comp.volt'], top['battery_temp_comp.temp']))

输出：

#######################################

设置：检查根问题是否存在潜在问题...

没有指定记录器，因此不会保存数据。组 '' 具有以下周期： [['battery_temp_comp', 'battery_volt_comp']]

以下参数连接到无序更新的未知数，因此它们的初始值可能包含未初始化的未知值：['battery_temp_comp.volt']

设置：根问题检查完成。

#######################################

参数： BatteryTempImplicitComp.volt：12.0
未知数：BatteryTempImplicitComp.temp：100.0 Resids：BatteryTempImplicitComp.temp
：0.0
参数：BatteryVoltImplicitComp.temp：100.0
未知数：BatteryVoltImplicitComp.volt：12.0 Resids： BatteryVoltImplicitComp.volt
：0.0
参数：BatteryVoltImplicitComp.temp：100。
：BatteryVoltImplicitComp.volt：12.0
Resids：BatteryVoltImplicitComp.volt：-1.41018689
参数：BatteryVoltImplicitComp.temp：99.9999
未知数：BatteryVoltImplicitComp.volt：12.0
Resids：BatteryVoltImplicitComp.volt：-1.41018689
参数：BatteryVoltImplicitComplicits12.00
UnmplicitComplicit.0.0
残差：BatteryVoltImplicitComp.volt：-1.41018689
参数：BatteryVoltImplicitComp.temp：100.0
未知数：BatteryVoltImplicitComp.volt：11.9999 残差
：BatteryVoltImplicitComp.volt：-1.41018689
参数：BatteryTempImplicitComp.volt：12.0001
未知数：BatteryTempImplicitComp.Temp
： ResourceComplicit.00000000000000 -19.4
参数：BatteryTempImplicitComp.volt：11.9999
未知数：BatteryTempImplicitComp.temp：100.0残基：BatteryTempImplicitComp.temp
：-19.4
参数：BatteryTempImplicitComp.volt：12.0
未知数：BatteryTempImplicitComp.temp：100.0001 残基：BatteryTempImplicitComp.temp
：-19.4
参数： BatteryTempImp伏特：12.0
Unknowns: BatteryTempImplicitComp.temp: 99.9999
Resids : BatteryTempImplicitComp.temp : -19.4
Params : BatteryTempImplicitComp.volt: 11.3436283598 Unknowns: BatteryTempImplicitComp.temp: 74.2988322548 Resids: BatteryTempImplicitComp.temp : -19.4 Params: BatteryVoltImplicitComp.temp: 74.2988322548 Unknowns: BatteryVoltImplicitComp.volt: 11.3436283598 Resids : BatteryVoltImplicitComp.volt: -1.41018689 Params: BatteryVoltImplicitComp.temp: 74.2989322548 Unknowns: BatteryVoltImplicitComp.volt: 11.3436283598 Resids : BatteryVoltImplicitComp.volt: 1.77166725734e-10 Params: BatteryVoltImplicitComp.temp: 74.2987322548









Unknowns: BatteryVoltImplicitComp.volt: 11.3436283598 Resids
: BatteryVoltImplicitComp.volt: 1.77166725734e-10
Params: BatteryVoltImplicitComp.temp: 74.2988322548
Unknowns: BatteryVoltImplicitComp.volt: 11.3437283598 Resids
: BatteryVoltImplicitComp.volt: 1.77166725734e-10
Params: BatteryVoltImplicitComp.temp: 74.2988322548
Unknowns: BatteryVoltImplicitComp.volt: 11.3435283598 Resids
: BatteryVoltImplicitComp.volt: 1.77166725734e-10
Params: BatteryTempImplicitComp.volt: 11.3437283598
Unknowns: BatteryTempImplicitComp.temp: 74.2988322548 Resids: BatteryTempImplicitComp.temp
: 0.172329491217
Params: BatteryTempImplicitComp.volt: 11.3435283598
Unknowns: BatteryTempImplicitComp.temp
: 74.2988322548 Resids: BatteryTempImplicitComp.temp: 0.172329491217
Params: BatteryTempImplicitComp.volt: 11.3436283598
Unknowns: BatteryTempImplicitComp.temp: 74.2989322548 Resids: BatteryTempImplicitComp.temp
: 0.172329491217
Params: BatteryTempImplicitComp.volt: 11.3436283598
Unknowns: BatteryTempImplicitComp.temp: 74.2987322548
Resids ：BatteryTempImplicitComp.temp：0.172329491217
参数：BatteryTempImplicitComp.volt：11.3396364502
未知数：BatteryTempImplicitComp.temp ：74.4349355547 残留物：BatteryTempImplicitComp.temp
：0.172329491217
参数：BatteryVoltImplicit355547477
Unknowns: BatteryVoltImplicitComp.volt: 11.3396364502 Resids
: BatteryVoltImplicitComp.volt: 1.77166725734e-10
Params: BatteryVoltImplicitComp.temp: 74.4350355547
Unknowns: BatteryVoltImplicitComp.volt: 11.3396364502 Resids
: BatteryVoltImplicitComp.volt: 2.87769807983e-13
Params: BatteryVoltImplicitComp.temp: 74.4348355547
Unknowns: BatteryVoltImplicitComp.volt: 11.3396364502 Resids
: BatteryVoltImplicitComp.volt: 2.87769807983e-13
Params: BatteryVoltImplicitComp.temp: 74.4349355547
Unknowns: BatteryVoltImplicitComp.volt: 11.3397364502 Resids
: BatteryVoltImplicitComp.volt: 2.87769807983e-13
Params: BatteryVoltImplicitComp.temp: 74.4349355547
Unknowns: BatteryVoltImplicitComp.volt: 11.3395364502 Resids
: BatteryVoltImplicitComp.volt: 2.87769807983e-13
Params: BatteryTempImplicitComp.volt: 11.3397364502
Unknowns : BatteryTempImplicitComp.temp: 74.4349355547 Resids: BatteryTempImplicitComp.temp
: 6.37414106563e-06
Params: BatteryTempImplicitComp.volt: 11.3395364502
Unknowns: BatteryTempImplicitComp.temp : 74.4349355547 Resids: BatteryTempImplicitComp.temp
: 6.37414106563e-06
Params: BatteryTempImplicitComp.volt: 11.3396364502
Unknowns: BatteryTempImplicitComp.temp: 74.4350355547 Resids: BatteryTempImplicitComp.temp
: 6.37414106563e-06
Params: BatteryTempImplicitComp.volt: 11.3396364502
Unknowns: BatteryTempImplicitComp.temp
: 74.4348355547
Resids
: BatteryTempImplicitComp.temp : 6.37414106563e-06 Params: BatteryTempImplicitComp.volt: 11.3396363025 Unknowns: BatteryTempImplicitComp.temp: 74.4349405893 Resids: BatteryTempImplicitComp.temp
: 6.37414106563e-06
Params: BatteryVoltImplicitComp.temp: 74.4349405893
Unknowns: BatteryVoltImplicitComp.volt：11.3396363025 残差
：BatteryVoltImplicitComp.volt：2.87769807983e-13
解决方案（battery_volt_comp）：伏特 = 11.3396363025，温度 = 74.4349405893
解决方案（电池_温度补偿）：伏特 = 1058974636349393

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