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https://github.com/odriverobotics/ODrive.git
synced 2026-09-23 17:13:47 +08:00
fix use of old motor object when calculating derived parameters
This commit is contained in:
Oskar Weigl
@@ -8,9 +8,10 @@ from engineering_notation import EngNumber
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filename = "oscilloscope.csv"
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PLOT_INITAL = True
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DO_FITTING = True
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PLOT_PROGRESS = False
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REPORT_PROGRESS = True
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assumed_rotor_resistance = 1.0 # (TODO: set to None to estimate)
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assumed_rotor_resistance = 1
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class ACMotor():
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"""
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@@ -104,13 +105,51 @@ class ACMotor():
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rotor_current = (1/rotor_inductance) * (y[1] - self.get_mutual_inductance() * y[0])
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return np.vstack((y, rotor_current))
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def print_parameter_info(self):
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print()
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print('Given parameters:')
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print('rotor_resistance = {}ohm'.format(EngNumber(assumed_rotor_resistance)))
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print()
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print('Fitted parameters:')
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for i, r in enumerate(ACMotor.parameter_definitions):
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print('{} = {}{}'.format(r[0], EngNumber(self.params[i]), r[2]))
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print()
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print('Derived parameters:')
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mutual_inductance = motor.get_mutual_inductance()
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coupling_factor = mutual_inductance / self.params[ACMotor.pl['rotor_inductance']]
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torque_constant = coupling_factor * mutual_inductance
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print('mutual_inductance = {}H'.format(EngNumber(mutual_inductance)))
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print('coupling_factor = {}'.format(EngNumber(coupling_factor)))
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print('torque_constant = {}Nm/A^2'.format(EngNumber(torque_constant)))
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def print_run_info(self, y):
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final_stator_current_d = np.real(y[0,-1])
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final_stator_current_q = np.imag(y[0,-1])
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final_rotor_flux_d = np.real(y[1,-1])
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mutual_inductance = self.get_mutual_inductance()
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coupling_factor = mutual_inductance / self.params[ACMotor.pl['rotor_inductance']]
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final_torque_per_q_amp = coupling_factor * final_rotor_flux_d
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print()
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print('Final values:')
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print('final_rotor_flux_d = {}Wb'.format(EngNumber(final_rotor_flux_d)))
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print('final_stator_current_d = {}A'.format(EngNumber(final_stator_current_d)))
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print('final_stator_current_q = {}A'.format(EngNumber(final_stator_current_q)))
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print('final_torque_per_q_amp = {}Nm/A'.format(EngNumber(final_torque_per_q_amp)))
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def plot_data(t, y, ref, title):
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fig, (ax1, ax2) = plt.subplots(2, sharex=True)
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ax1b = ax1.twinx()
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ax1.plot(t, ref, label='Measured current')
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ax1.plot(t, y[0], label='Stator current')
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ax2.plot(t, y[2], label='Rotor current')
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ax1b.plot(t, 1000*y[1], 'g', label='Rotor flux')
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ax1.plot(t, np.real(y[0]), label='Stator current (d)')
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ax1.plot(t, np.imag(y[0]), label='Stator current (q)')
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ax2.plot(t, np.real(y[2]), label='Rotor current (d)')
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ax2.plot(t, np.imag(y[2]), label='Rotor current (q)')
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ax1b.plot(t, 1000*np.real(y[1]), 'C2', label='Rotor flux (d)')
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ax1b.plot(t, 1000*np.imag(y[1]), 'C3', label='Rotor flux (q)')
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ax1.set_xlabel('time [s]')
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ax1.set_ylabel('Current [A]')
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ax1b.set_ylabel('Flux [mWb]')
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@@ -119,7 +158,6 @@ def plot_data(t, y, ref, title):
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fig.legend()
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plt.show()
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# load test data
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t = np.arange(4096)/8000.0
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voltage_step = 1.0
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@@ -128,12 +166,12 @@ with open(filename, 'r') as fp:
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inital_parameters = np.zeros(len(ACMotor.parameter_definitions))
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inital_parameters[ACMotor.pl['stator_inductance']] = 6.205440877238289e-05
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inital_parameters[ACMotor.pl['stator_resistance']] = 0.031451061367988586
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inital_parameters[ACMotor.pl['rotor_inductance']] = 0.25e-0
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inital_parameters[ACMotor.pl['stator_inductance']] = 7.72181086e-04
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inital_parameters[ACMotor.pl['stator_resistance']] = 3.06884624e-02
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inital_parameters[ACMotor.pl['rotor_inductance']] = assumed_rotor_resistance*6.82013522e-02
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# inital_parameters[ACMotor.pl['rotor_resistance']] = 1.0e-0
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# inital_parameters[ACMotor.pl['mutual_inductance']] = 2.40e-4
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inital_parameters[ACMotor.pl['mutual_inductance_factor']] = 0.8
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inital_parameters[ACMotor.pl['mutual_inductance_factor']] = 8.68671978e-01
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# inital_parameters[ACMotor.pl['stator_resistance']] = 1.298
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# inital_parameters[ACMotor.pl['stator_inductance']] = 0.157228647
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@@ -142,14 +180,18 @@ inital_parameters[ACMotor.pl['mutual_inductance_factor']] = 0.8
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# inital_parameters[ACMotor.pl['mutual_inductance']] = 0.157221177
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# Plot initial run
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if(PLOT_INITAL):
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if PLOT_INITAL:
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print()
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print('Initial run:')
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motor = ACMotor(inital_parameters)
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motor.print_parameter_info()
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y = motor.run(
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time_series = t,
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voltage = voltage_step,
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omega_stator = 0,
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omega_rotor= 0)
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motor.print_run_info(y)
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plot_data(t, y, test_response, 'initial')
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@@ -167,58 +209,34 @@ def get_residuals(params):
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fitness = sum(residuals**2)
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if REPORT_PROGRESS: print(fitness)
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if(PLOT_PROGRESS):
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if PLOT_PROGRESS:
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plot_data(t, y, test_response, 'progress')
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return residuals
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optiresult = least_squares(get_residuals, inital_parameters,
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bounds=list(zip(*[x[1] for x in ACMotor.parameter_definitions])),
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x_scale='jac',
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diff_step = 1e-2 * np.array([
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7.58192590e-04,
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3.07166671e-02,
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6.85207075e-02,
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# 4.66461518e+00,
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8.67540012e-01])
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)
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print(optiresult.message)
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if DO_FITTING:
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print()
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print('Fitting parameters:')
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optiresult = least_squares(get_residuals, inital_parameters,
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bounds=list(zip(*[x[1] for x in ACMotor.parameter_definitions])),
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x_scale='jac',
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diff_step = 1e-2 * np.array([
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7.58192590e-04,
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3.07166671e-02,
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6.85207075e-02,
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# 4.66461518e+00,
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8.67540012e-01])
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)
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print(optiresult.message)
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print()
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print('Given parameters:')
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print('rotor_resistance = {}ohm'.format(EngNumber(assumed_rotor_resistance)))
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motor = ACMotor(optiresult.x)
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motor.print_parameter_info()
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print()
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print('Fitted parameters:')
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for i, r in enumerate(ACMotor.parameter_definitions):
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print('{} = {}{}'.format(r[0], EngNumber(optiresult.x[i]), r[2]))
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print()
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print('Derived parameters:')
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mutual_inductance = motor.get_mutual_inductance()
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coupling_factor = mutual_inductance / optiresult.x[ACMotor.pl['rotor_inductance']]
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torque_constant = coupling_factor * mutual_inductance
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print('mutual_inductance = {}H'.format(EngNumber(mutual_inductance)))
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print('coupling_factor = {}'.format(EngNumber(coupling_factor)))
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print('torque_constant = {}Nm/A^2'.format(EngNumber(torque_constant)))
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motor = ACMotor(optiresult.x)
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y = motor.run(
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time_series = t,
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voltage = voltage_step,
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omega_stator = 0,
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omega_rotor= 0)
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final_stator_current = np.real(y[0,-1])
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final_rotor_flux = np.real(y[1,-1])
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final_torque_per_amp = coupling_factor * final_rotor_flux
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print()
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print('Final values:')
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print('final_rotor_flux = {}Wb'.format(EngNumber(final_rotor_flux)))
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print('final_stator_current = {}A'.format(EngNumber(final_stator_current)))
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print('final_torque_per_amp = {}Nm/A'.format(EngNumber(final_torque_per_amp)))
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plot_data(t, y, test_response, 'final')
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y = motor.run(
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time_series = t,
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voltage = voltage_step,
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omega_stator = 0,
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omega_rotor= 0)
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motor.print_run_info(y)
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plot_data(t, y, test_response, 'final')
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