Nonlinear system modeling method for motor and modeling device

Patent metadata

Field	Value
Publication number	US-12333221-B2
Application number	US-202117566639-A
Country	US
Kind code	B2
Filing date	Dec 30, 2021
Priority date	May 10, 2021
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

The invention provides a motor nonlinear system modeling method including steps of: obtaining a chirp signal of a first frequency band, and a chirp signal of a second frequency band; exciting the motor by using the chirp signal; obtaining a higher harmonic frequency response of the first frequency band; exciting the motor by using the chirp signal of the second frequency band; obtaining a higher harmonic frequency response of the second frequency band; obtaining a higher harmonic frequency response by splicing the higher harmonic frequency response of the first frequency band and the higher harmonic frequency response of the second frequency band in the frequency domain. The higher harmonic frequency response of the working frequency of the motor is a nonlinear system model of the motor. By virtue of the method provided by the present invention, the accuracy of motor modeling is effectively improved.

First claim

What is claimed is:

1. A nonlinear system modeling method for controlling a motor, including steps of:
obtaining a chirp signal of a first frequency band in a working frequency s of the motor, and a chirp signal of a second frequency band in the working frequency of the motor;
wherein a start frequency of the first frequency band is a start frequency of the working frequency of the motor, a cut-off frequency of the second frequency band is a cut-off frequency of the working frequency of the motor, and the first frequency band partially overlaps the second frequency band;

wherein a chirp signal comprises a variable a(t) which is a function of frequency that changes with time (t); wherein the value of a(t) is set at a low constant value at certain frequency points where the motor is easy to shell;
exciting the motor by using the chirp signal of the first frequency band to obtaining a first output;
obtaining a higher harmonic frequency response of the first frequency band according to the first output and the chirp signal of the first frequency is band;
exciting the motor by using the chirp signal of the second frequency band to obtain a second output;
obtaining a higher harmonic frequency response of the second frequency band according to the second output and the chirp signal of the second frequency band;
determining a higher harmonic frequency response of the working frequency of the motor by splicing the higher harmonic frequency response of the first frequency band and the higher harmonic frequency response of the second frequency band in the frequency domain to ensure an accuracy of a nonlinear system model of the motor;
wherein the higher harmonic frequency response of the working frequency of the motor is the nonlinear system model of the motor which is used for controlling.

2. The nonlinear system modeling method for a motor as described in claim 1 further including steps of:
obtaining a first preset frequency and a second preset frequency greater than the first preset frequency;
determining a frequency band of the working frequency of the motor that is less than or equal to the second preset frequency as the first frequency band;
determining a frequency band of the working frequency of the motor that is greater than or equal to the first preset frequency as the second frequency band;

wherein the step of obtaining the higher harmonic frequency response of the working frequency of the motor by splicing the higher harmonic frequency response of the first frequency band and the higher harmonic frequency response of the second frequency band in the frequency domain, includes steps of:
obtaining a third preset frequency between the first preset frequency and the second preset frequency;
truncating a higher harmonic frequency response of the third frequency band from the higher harmonic frequency response of the first frequency band; wherein a start frequency of the third frequency band is the start frequency of the first frequency band; a cut-off frequency of the third frequency band is the third preset frequency; truncating a higher harmonic frequency response of a fourth frequency band from the higher harmonic frequency response of the second frequency band; wherein a start frequency of the fourth frequency band is the third preset frequency; a cut-off frequency of the fourth frequency band is the cut-off frequency of the second frequency band;
obtaining a higher harmonic frequency response of the working frequency of the motor by splicing the higher harmonic frequency response of the third frequency band and the higher harmonic frequency response of the fourth frequency band in the frequency domain.

3. The nonlinear system modeling method for a motor as described in claim 1 further including steps of:
obtain a fourth preset frequency;
determining a frequency band of the working frequency of the motor that is less than or equal to the fourth preset frequency as the first frequency band;
determining a frequency band greater than or equal to the fourth preset frequency in the working frequency of the motor as the second frequency band.

4. The nonlinear system modeling method for a motor as described in claim 1 , wherein the step of obtaining the higher harmonic frequency response of the first frequency band in the first output and the chirp signal of the first frequency band includes steps of:
using Fourier transform on the first output to obtain the first frequency domain response;
according to the first frequency domain response, using an inverse signal frequency domain of the chirp signal of the first frequency band to analyze and calculate the first response function of the motor system;
using the first response function to obtain a first kernel function through conversion matrix conversion;
obtaining the higher harmonic frequency response of the first frequency band from the chirp signal of the first frequency band and the first kernel function; wherein the step of obtaining the higher harmonic frequency response of the second frequency band according to the second output and the chirp signal of the second frequency band includes steps of:
using Fourier transform on the second output to obtain the second frequency domain response;
according to the second frequency domain response, using an inverse signal frequency domain of the chirp signal of the second frequency band to analyze and calculate the second response function of the motor system;
using a second response function to obtain the second kernel function through conversion matrix conversion; obtaining the higher harmonic frequency response of the second frequency band from the chirp signal of the second frequency band and the second kernel function.

5. The nonlinear system modeling method for a motor as described in claim 1 , wherein: the chirp signal is calculated by the following formula:

x
⁡
(
t
)

=

a
⁡
(
t
)

⁢

sin
[

2
⁢
π
⁢

f
1

⁢
L
⁢

exp
⁡
(

t
L

)

]

L
=

T

ln
⁡
(

f
2

f
1

)

where, f 1 is the start frequency of the chirp signal, a(t) is the amplitude, and t is the time, that is, a(t) is the function of the frequency that changes with time, T is the length of the chirp signal, and f 2 is the chirp signal cut-off frequency.

6. A nonlinear system modeling method for

Assignees

• Aac Acousitc Tech Shanghai Co Ltd
• Aac Acoustic Tech Shanghai Co Ltd

Inventors

• Cao Zhongqing
• Xiang Zheng
• Guo Xuan

Classifications

• H02P29/00

  Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors (arrangements for starting electric motors H02P1/00; arrangements for stopping or slowing electric motors H02P3/00; control of motors that can be connected to two or more different electric power supplies H02P4/00; regulating or controlling the speed or torque of two or more electric motors H02P5/00; vector control H02P21/00) · CPC title

• G06F30/17

  Mechanical parametric or variational design · CPC title

• G06F30/15

  Vehicle, aircraft or watercraft design · CPC title

• G06F30/20 Primary

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• G06F17/15

  Correlation function computation {including computation of convolution operations (arithmetic circuits for sum of products per se, e.g. multiply-accumulators G06F7/5443; digital filters, e.g. FIR, IIR, adaptive filters H03H17/00)} · CPC title