Question

使用 OpenMDAO v1.7.3 Alpha

我有一个简单的示例OpenMDAO问题，其中包含2个隐式组件：

第一个组件使用温度来计算电压
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，它未能收敛。我认为问题是我没有设置初始参数值。因为OpenMDAO正在打印以下消息以输出：

以下参数与未知变量连接，这些未知变量会不按顺序更新，因此它们的初始值可能包含未初始化的未知值：['battery_temp_comp.volt']

我一直在搜寻documentation，但无法弄清楚如何正确设置这种类型的问题（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：正在检查根本问题以发现潜在问题...

未指定记录器，因此不会保存任何数据。组''   具有以下周期：[[''battery_temp_comp'，'battery_volt_comp']]

以下参数与未知对象相关联，这些未知对象通过更新   顺序，因此它们的初始值可能包含未初始化的未知数   值：['battery_temp_comp.volt']

设置：根本问题检查完毕。
     #######################################
参数：BatteryTempImplicitComp.volt：12.0
  未知：BatteryTempImplicitComp.temp：30.0
  残留物：BatteryTempImplicitComp.delta：0.0
  参数：BatteryVoltImplicitComp.temp：30.0
  未知数：BatteryVoltImplicitComp.volt：12.0
  残留物：BatteryVoltImplicitComp.delta：0.0
  参数：BatteryTempImplicitComp.volt：12.1
  未知：BatteryTempImplicitComp.temp：30.0
  残留物：BatteryTempImplicitComp.delta：50.6
  参数：BatteryTempImplicitComp.volt：11.9
  未知：BatteryTempImplicitComp.temp：30.0
  残留物：BatteryTempImplicitComp.delta：50.6
  参数：BatteryTempImplicitComp.volt：12.0
  未知：BatteryTempImplicitComp.temp：30.0
  残留物：BatteryTempImplicitComp.delta：50.6
  参数：BatteryTempImplicitComp.volt：12.0
  未知：BatteryTempImplicitComp.temp：30.0
  残留物：BatteryTempImplicitComp.delta：50.6
  参数：BatteryVoltImplicitComp.temp：30.1
  未知数：BatteryVoltImplicitComp.volt：12.0
  残留物：BatteryVoltImplicitComp.delta：0.64291311
  参数：BatteryVoltImplicitComp.temp：29.9
  未知数：BatteryVoltImplicitComp.volt：12.0
  残留物：BatteryVoltImplicitComp.delta：0.64291311

...

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

Answer 1

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，它未能收敛。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语句的顺序确定。 Group.list_order()将打印出组中组件的执行顺序。

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：正在检查根本问题以发现潜在问题...

未指定记录器，因此不会保存任何数据。组''   具有以下周期：[[''battery_temp_comp'，'battery_volt_comp']]

以下参数与无序更新的未知数相关，   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：根本问题检查完毕。
     #######################################
参数：BatteryTempImplicitComp.volt：12.0
  未知：BatteryTempImplicitComp.temp：100.0
  残留物：BatteryTempImplicitComp.temp：0.0
  参数：BatteryVoltImplicitComp.temp：100.0
  未知数：BatteryVoltImplicitComp.volt：12.0
  残留物：BatteryVoltImplicitComp.volt：0.0
  参数：BatteryVoltImplicitComp.temp：100.0001
  未知数：BatteryVoltImplicitComp.volt：12.0
  残留物：BatteryVoltImplicitComp.volt：-1.41018689
  参数：BatteryVoltImplicitComp.temp：99.9999
  未知数：BatteryVoltImplicitComp.volt：12.0
  残留物：BatteryVoltImplicitComp.volt：-1.41018689
  参数：BatteryVoltImplicitComp.temp：100.0
  未知数：BatteryVoltImplicitComp.volt：12.0001
  残留物：BatteryVoltImplicitComp.volt：-1.41018689
  参数：BatteryVoltImplicitComp.temp：100.0
  未知数：BatteryVoltImplicitComp.volt：11.9999
  残留物：BatteryVoltImplicitComp.volt：-1.41018689
  参数：BatteryTempImplicitComp.volt：12.0001
  未知：BatteryTempImplicitComp.temp：100.0
  残留物：BatteryTempImplicitComp.temp：-19.4
  参数：BatteryTempImplicitComp.volt：11.9999
  未知：BatteryTempImplicitComp.temp：100.0
  残留物：BatteryTempImplicitComp.temp：-19.4
  参数：BatteryTempImplicitComp.volt：12.0
  未知：BatteryTempImplicitComp.temp：100.0001
  残留物：BatteryTempImplicitComp.temp：-19.4
  参数：BatteryTempImplicitComp.volt：12.0
  未知：BatteryTempImplicitComp.temp：99.9999
  残留物：BatteryTempImplicitComp.temp：-19.4
  参数：BatteryTempImplicitComp.volt：11.3436283598
  未知：BatteryTempImplicitComp.temp：74.2988322548
  残留物：BatteryTempImplicitComp.temp：-19.4
  参数：BatteryVoltImplicitComp.temp：74.2988322548
  未知数：BatteryVoltImplicitComp.volt：11.3436283598
  残留物：BatteryVoltImplicitComp.volt：-1.41018689
  参数：BatteryVoltImplicitComp.temp：74.2989322548
  未知数：BatteryVoltImplicitComp.volt：11.3436283598
  残留物：BatteryVoltImplicitComp.volt：1.77166725734e-10
  参数：BatteryVoltImplicitComp.temp：74.2987322548
  未知数：BatteryVoltImplicitComp.volt：11.3436283598
  残留物：BatteryVoltImplicitComp.volt：1.77166725734e-10
  参数：BatteryVoltImplicitComp.temp：74.2988322548
  未知数：BatteryVoltImplicitComp.volt：11.3437283598
  残留物：BatteryVoltImplicitComp.volt：1.77166725734e-10
  参数：BatteryVoltImplicitComp.temp：74.2988322548
  未知数：BatteryVoltImplicitComp.volt：11.3435283598
  残留物：BatteryVoltImplicitComp.volt：1.77166725734e-10
  参数：BatteryTempImplicitComp.volt：11.3437283598
  未知：BatteryTempImplicitComp.temp：74.2988322548
  残留物：BatteryTempImplicitComp.temp：0.172329491217
  参数：BatteryTempImplicitComp.volt：11.3435283598
  未知：BatteryTempImplicitComp.temp：74.2988322548
  残留物：BatteryTempImplicitComp.temp：0.172329491217
  参数：BatteryTempImplicitComp.volt：11.3436283598
  未知：BatteryTempImplicitComp.temp：74.2989322548
  残留物：BatteryTempImplicitComp.temp：0.172329491217
  参数：BatteryTempImplicitComp.volt：11.3436283598
  未知：BatteryTempImplicitComp.temp：74.2987322548
  残留物：BatteryTempImplicitComp.temp：0.172329491217
  参数：BatteryTempImplicitComp.volt：11.3396364502
  未知：BatteryTempImplicitComp.temp：74.4349355547
  残留物：BatteryTempImplicitComp.temp：0.172329491217
  参数：BatteryVoltImplicitComp.temp：74.4349355547
  未知数：BatteryVoltImplicitComp.volt：11.3396364502
  残留物：BatteryVoltImplicitComp.volt：1.77166725734e-10
  参数：BatteryVoltImplicitComp.temp：74.4350355547
  未知数：BatteryVoltImplicitComp.volt：11.3396364502
  残留物：BatteryVoltImplicitComp.volt：2.87769807983e-13
  参数：BatteryVoltImplicitComp.temp：74.4348355547
  未知数：BatteryVoltImplicitComp.volt：11.3396364502
  残留物：BatteryVoltImplicitComp.volt：2.87769807983e-13
  参数：BatteryVoltImplicitComp.temp：74.4349355547
  未知数：BatteryVoltImplicitComp.volt：11.3397364502
  残留物：BatteryVoltImplicitComp.volt：2.87769807983e-13
  参数：BatteryVoltImplicitComp.temp：74.4349355547
  未知数：BatteryVoltImplicitComp.volt：11.3395364502
  残留物：BatteryVoltImplicitComp.volt：2.87769807983e-13
  参数：BatteryTempImplicitComp.volt：11.3397364502
  未知：BatteryTempImplicitComp.temp：74.4349355547
  残留物：BatteryTempImplicitComp.temp：6.37414106563e-06
  参数：BatteryTempImplicitComp.volt：11.3395364502
  未知：BatteryTempImplicitComp.temp：74.4349355547
  残留物：BatteryTempImplicitComp.temp：6.37414106563e-06
  参数：BatteryTempImplicitComp.volt：11.3396364502
  未知：BatteryTempImplicitComp.temp：74.4350355547
  残留物：BatteryTempImplicitComp.temp：6.37414106563e-06
  参数：BatteryTempImplicitComp.volt：11.3396364502
  未知：BatteryTempImplicitComp.temp：74.4348355547
  残留物：BatteryTempImplicitComp.temp：6.37414106563e-06
  参数：BatteryTempImplicitComp.volt：11.3396363025
  未知：BatteryTempImplicitComp.temp：74.4349405893
  残留物：BatteryTempImplicitComp.temp：6.37414106563e-06
  参数：BatteryVoltImplicitComp.temp：74.4349405893
  未知数：BatteryVoltImplicitComp.volt：11.3396363025
  残留物：BatteryVoltImplicitComp.volt：2.87769807983e-13
  解决方案（battery_volt_comp）：伏特= 11.3396363025，温度= 74.4349405893
  解决方案（battery_temp_comp）：伏特= 11.3396363025，温度= 74.4349405893

隐式组件：设置初始参数值

1 个答案: