CN116317781A - Unbalanced Vibration Control Method and Device for Coaxial Dual Rotor System Based on Slight Speed Difference - Google Patents

Abstract

The invention discloses a method and a device for controlling unbalanced vibration of a coaxial double-rotor system, wherein the method comprises the following steps: obtaining vibration signals of the coaxial double rotors, wherein the vibration signals comprise acceleration signals and key phase signals; extracting characteristics of the vibration signals to obtain input parameters, wherein the input parameters comprise the amplitude and the phase of an initial unbalanced vibration vector of the coaxial double rotors and the amplitude and the phase of an unbalanced vibration vector after the coaxial double rotors are subjected to test weight; and calculating vibration suppression parameters by using an influence coefficient method according to the input parameters so as to add weights corresponding to the vibration suppression parameters to the weight plates of the coaxial double rotors, wherein the vibration suppression parameters comprise mass and phase of unbalance. The technical problems that in the prior art, extraction accuracy is insufficient and the extraction accuracy is seriously dependent on data length when a micro-speed difference dual-rotor beat signal is separated are solved.

Description

Unbalanced Vibration Control Method and Device for Coaxial Dual Rotor System Based on Slight Speed Difference

technical field

The invention relates to the technical field of high-end mechanical equipment, in particular to a method and device for controlling unbalanced vibration of a coaxial dual-rotor system based on a slight speed difference.

Background technique

The coaxial dual-rotor system has been widely used in aero-engines, and the unbalanced fault is one of the main faults of the dual-rotor system, which poses a great threat to the safe and stable operation of the aero-engine. The coaxial double rotor has an inner rotor and an outer rotor, and the inner and outer rotors are connected together by inter-shaft bearings. When there is a slight difference in speed between the inner rotor and the outer rotor, the vibration frequency of the two rotors is close, and the vibration signal is expressed as beat signal. The beating vibration signal is composed of a sinusoidal signal with the same rotational frequency as the inner rotor, a sinusoidal signal with the same rotational frequency as the outer rotor, and a noise signal. Since the rotation frequencies of the outer rotor and the inner rotor are very close, it is very difficult to extract the respective vibration characteristics of the outer rotor and the inner rotor from the vibration signal. Different from the unbalance fault of the single-rotor system, the inner and outer rotors of the double-rotor system are connected by inter-shaft bearings, so the unbalanced vibration signals of the inner and outer rotors interfere with each other, especially when the speeds of the inner and outer rotors are similar, the inner and outer rotors are unbalanced. The real-time separation of beat vibration signals formed by balanced vibration has become a key problem that needs to be solved urgently.

At present, in some existing technologies, in the extraction method of the unbalanced feature of the micro-speed difference signal, the extraction method of the unbalanced component of the micro-speed difference dual-rotor system based on spectrum correction, the power frequency component that triggers the reference rotor is directly extracted from the spectrum, and the other The power frequency component and phase of a rotor are obtained by phase difference spectrum correction. However, the vibration signals of the inner and outer rotors interfere with each other, and the operating frequencies are similar. The existing methods are difficult to separate the micro-speed difference signals, and the extraction accuracy and efficiency are not good, which depends heavily on the sampling time and data length.

Therefore, a method and device for unbalanced vibration control of a coaxial dual-rotor system based on a micro-speed difference is provided to solve the problem of insufficient extraction accuracy in the separation of the micro-speed difference dual-rotor beating vibration signals in the prior art, and the extraction accuracy is heavily dependent on the data The problem of length has just become a problem to be solved urgently by those skilled in the art.

Contents of the invention

For this reason, embodiments of the present invention provide a method and device for unbalanced vibration control of a coaxial dual-rotor system based on a micro-speed difference to solve the problem of insufficient extraction accuracy in the separation of the micro-speed-difference dual-rotor beating vibration signals in the prior art, and the extraction Accuracy is heavily dependent on technical issues of data length.

In order to achieve the above purpose, embodiments of the present invention provide the following technical solutions:

A method for controlling unbalanced vibration of a coaxial dual-rotor system, the method comprising:

Acquiring vibration signals of the coaxial dual rotors, the vibration signals including acceleration signals and key phase signals;

Perform feature extraction on the vibration signal to obtain input parameters, the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and the coaxial dual rotors after adding a test weight Magnitude and phase of the unbalanced vibration vector;

According to the input parameters, the vibration suppression parameters are calculated by using the influence coefficient method, so that the counterweight corresponding to the vibration suppression parameters can be added to the counterweight plate of the coaxial double rotor, and the vibration suppression parameters include the unbalance amount quality and phase.

In some embodiments, obtaining vibration signals of coaxial dual rotors specifically includes:

Setting the frequency of the inner rotor and the frequency of the outer rotor in the coaxial double rotor, so that the frequency difference between the inner and outer rotors is less than a preset frequency value, so that the inner and outer rotors are in a state of slight speed difference;

In the state of the slight speed difference, the horizontal acceleration, vertical acceleration and key phase signals of the inner and outer rotors in the starting state are respectively collected.

In some embodiments, feature extraction is performed on the vibration signal to obtain input parameters, specifically including:

Based on the acceleration signal, calculate the amplitude and phase of the initial unbalanced vibration vector of the inner and outer rotors in the coaxial dual rotor;

When the coaxial double rotors are in a stopped state, the test weight operation is performed on the inner and outer rotors respectively;

When the coaxial dual rotors are running, detecting the acceleration signal after the test weight is added;

Based on the acceleration signal after the test weight is added, the amplitude and phase of the unbalanced vibration vector of the coaxial dual rotors after the test weight is added are calculated and obtained.

In some embodiments, based on the acceleration signal, the amplitude and phase of the initial unbalanced vibration vector of the inner and outer rotors in the coaxial dual rotors are calculated, specifically including:

Perform windowing processing on the frequency response of the low-pass filter, and use the frequency response after windowing to filter the original signal of the acceleration signal to obtain a filtered signal;

Complex modulation frequency shifting is performed on the filtered signal to obtain a frequency shifted signal;

determining the frequency range and the number of spectral lines of the frequency-shifted signal;

Performing a segmental DFT (discrete Fourier transform) operation on the frequency-shifted signal according to the frequency range and the number of spectral lines to obtain a segmented and refined spectrum of the signal;

The amplitude and phase of the initial unbalanced vibration vector are obtained by calculating the refined frequency spectrum according to the signal selection.

In some embodiments, the expression of the frequency response after windowing is:

In the formula, w ₁ is the low cut-off frequency of the complex analysis filter, w ₂ is the high cut-off frequency of the complex analysis filter, _we = (w ₁ + w ₂ )/2, and the complex analysis filter is the The low-pass filter is obtained by complex frequency shifting, H(k) is the frequency response after windowing, H ₀ (k) is the frequency response of the low-pass filter, w is windowing, and w _e is the frequency response of the complex analysis filter Center frequency, j is the imaginary number unit, k=1, 2, ..., N, where N is the number of spectrum analysis points.

In some embodiments, the expression of the filtered signal is:

x″[n]=x′[n]*H(k),k=M,D+M,...,(N-1)D+M

In the formula, x″[n] is the filtered signal, x′[n] is the signal obtained after sampling the original signal, H(k) is the frequency response after windowing, D is the refinement multiple, and M is Filter half order, N is the number of spectral analysis points.

The present invention also provides an unbalanced vibration control device for a coaxial dual-rotor system, the device comprising:

a signal acquisition unit, configured to acquire vibration signals of the coaxial dual rotors, the vibration signals including acceleration signals and key phase signals;

A signal processing unit, configured to perform feature extraction on the vibration signal to obtain input parameters, the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and the coaxial dual rotors The amplitude and phase of the unbalanced vibration vector after the rotor is added with test weight;

a parameter generating unit, configured to calculate a vibration suppression parameter by using an influence coefficient method according to the input parameters, so as to add the counterweight corresponding to the vibration suppression parameter to the counterweight plate of the coaxial double rotor, the Vibration suppression parameters include the mass and phase of the unbalance.

The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and operable on the processor, and the processor implements the steps of the above method when executing the program .

The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are realized.

The unbalanced vibration control method of the coaxial dual rotor system provided by the present invention obtains the vibration signal of the coaxial dual rotor, the vibration signal includes the acceleration signal and the key phase signal; and extracts the feature of the vibration signal to obtain the input parameters , the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and the amplitude and phase of the unbalanced vibration vector after adding a test weight to the coaxial dual rotors; according to the Input parameters, use the influence coefficient method to calculate the vibration suppression parameters, so that the counterweight corresponding to the vibration suppression parameters can be added to the counterweight plate of the coaxial double rotor, the vibration suppression parameters include the mass of the unbalanced quantity and phase. In this way, this method uses the algorithm combining ZFFT (refined Fast Fourier Transform) and DFT (Discrete Fourier Transform) to effectively separate the micro-speed beat vibration signal, extract the unbalanced vibration amplitude and phase of the double rotor, and extract As the input parameters of the influence coefficient method, the amplitude and phase of the unbalance are calculated by adding the test weight and counterweighted, so as to achieve the effect of controlling the unbalanced vibration of the micro-speed difference double rotor. The invention solves the technical problem of insufficient extraction accuracy existing in the prior art when separating the beating vibration signals of the double-rotors with slight speed difference, and the extraction accuracy is heavily dependent on the data length.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that are required in the description of the embodiments or the prior art. Apparently, the drawings in the following description are only exemplary, and those skilled in the art can also obtain other implementation drawings according to the provided drawings without creative work.

The structures, proportions, sizes, etc. shown in this manual are only used to cooperate with the content disclosed in the manual, so that people familiar with this technology can understand and read, and are not used to limit the conditions for the implementation of the present invention, so there is no technical In the substantive meaning above, any modification of structure, change of proportional relationship or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the functions and objectives of the present invention. within the range that can be covered.

Fig. 1 is one of the schematic flow charts of the unbalanced vibration control method of the coaxial dual rotor system provided by the present invention;

Fig. 2 is the second schematic flow diagram of the unbalanced vibration control method of the coaxial dual rotor system provided by the present invention;

Fig. 3 is the third schematic flow chart of the unbalanced vibration control method of the coaxial dual rotor system provided by the present invention;

Fig. 4 is the fourth schematic flow diagram of the unbalanced vibration control method of the coaxial dual rotor system provided by the present invention;

Figure 5 is the beat vibration simulation signal waveform with a frequency difference of 0.5 Hz;

Fig. 6 is three kinds of methods to the spectrum analysis of the micro speed difference signal of frequency difference 0.5Hz;

Figure 7 is a comparison of the relative errors of the three methods for extracting the amplitude at different speeds;

Figure 8 is the effect diagram before and after the balance of the inner and outer rotors under different differential speeds;

Fig. 9 is a structural block diagram of the unbalanced vibration control device for the coaxial dual-rotor system provided by the present invention;

FIG. 10 is a schematic diagram of the physical structure of the electronic device provided by the present invention.

Detailed ways

The implementation mode of the present invention is illustrated by specific specific examples below, and those who are familiar with this technology can easily understand other advantages and effects of the present invention from the contents disclosed in this description. Obviously, the described embodiments are a part of the present invention. , but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the coaxial dual-rotor system based on the micro-speed difference, the vibration signals of the inner and outer rotors interfere with each other, and the operating frequencies are similar. It is difficult to separate the micro-speed difference signal by traditional methods, and the extraction accuracy and rapidity are not good, which depends heavily on the sampling time and data length. Therefore, it is a key issue to separate and extract the inner and outer rotor vibration signals contained in the micro-speed difference signal. If the fast Fourier transform is used to process signals with similar frequencies, longer sampling time is required to obtain higher spectral resolution, but the minimum sampling time is required in real-time applications. The typical method of separating the beat vibration signals of two rotors with slight speed difference and extracting the unbalanced characteristics of the beat vibration signals is to use the least square method to correct the spectrum of adjacent frequencies, use the cross-correlation method to identify the characteristics of the slight speed difference signal, and directly pass the beat signal without decomposing the beat Methods of extracting the amplitude and frequency of the rotor, etc. However, the least squares method has poor recognition effect in the case of low signal-to-noise ratio, the correlation method has a certain loss of anti-noise ability when the integration time is short, and the unbeating method is difficult to extract the signal phase. When in use, the synchronization of the reference signal and the vibration signal is adjusted, and the steps are relatively complicated.

Aiming at the development of the coaxial dual-rotor system based on the micro-speed difference, the present invention proposes a micro-speed-difference-based The unbalanced vibration control method of the coaxial dual-rotor system, using ZFFT (refined Fast Fourier Transform) combined with DFT (Discrete Fourier Transform) ZFFT+FT (Refined Fast Fourier Transform combined with Discrete Fourier Transform) ) algorithm to effectively separate the beat vibration signal of the micro-speed difference, extract the unbalanced vibration amplitude and phase of the double rotor, use the extracted amplitude and phase as the input parameters of the influence coefficient method, and calculate the quality and phase of the unbalanced quantity by adding the test weight And counterweight, so as to achieve the effect of micro-speed difference dual-rotor unbalanced vibration control.

Generally speaking, in order to achieve the purpose of suppressing the unbalanced vibration of the inner and outer rotors in the unbalanced vibration of the dual rotors with a slight speed difference, the vibration signals of the coaxial dual rotors with a slight speed difference are collected first, and then the ZFFT+FT (refinement fast Fusion Fourier transform combined with discrete Fourier transform) algorithm to extract the features of the signal, and finally take the extracted vibration amplitude and phase as the input parameters of the influence coefficient method, and the output result is the quality and phase of the unbalanced quantity. The balance vector dynamically balances the inner and outer rotors.

In a specific embodiment, the unbalanced vibration control method of the coaxial dual rotor system provided by the present invention, as shown in Figure 1, the method includes the following steps:

S110: Obtain vibration signals of coaxial dual rotors, where the vibration signals include acceleration signals and key phase signals;

S120: Perform feature extraction on the vibration signal to obtain input parameters, the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and add a test weight to the coaxial dual rotors The magnitude and phase of the unbalanced vibration vector after;

S130: According to the input parameters, use the influence coefficient method to calculate vibration suppression parameters, so as to add the counterweight corresponding to the vibration suppression parameters to the counterweight plate of the coaxial double rotor, the vibration suppression parameters include Mass and phase of unbalanced quantities.

计算公式为：Specifically, the mass and phase of the unbalance are calculated by using the influence coefficient method, and the counterweights corresponding to the unbalance are added to the counterweight plates of the inner and outer rotors respectively, so that the unbalance vibration of the inner and outer rotors is suppressed, and the unbalance

The calculation formula is:

为内外转子的振动响应，/>

为加试重后的不平衡振动响应，/>

为试重矢量。In the formula,

is the vibration response of the inner and outer rotors, />

is the unbalanced vibration response after adding the test weight, />

is the trial weight vector.

In step S110, as shown in Figure 2, the vibration signals of the coaxial dual rotors are obtained, which specifically includes the following steps:

S210: Setting the frequency of the inner rotor and the frequency of the outer rotor in the coaxial dual rotors, so that the frequency difference between the inner and outer rotors is less than a preset frequency value, so that the inner and outer rotors are in a state of slight speed difference;

S220: In the state of the slight speed difference, respectively collect the horizontal acceleration, vertical acceleration and key phase signals of the inner and outer rotors in the starting state.

Specifically, in a specific usage scenario, the acceleration sensors in the horizontal and vertical directions are first installed on the double-rotor test bench with a small speed difference, and the acceleration sensors in the two directions are used to measure the difference between the horizontal and vertical directions of the rotor test bench. To balance the vibration signal, install two photoelectric sensors to measure the key-phase signals of the inner and outer rotors respectively. Use the serial port to send data to set the frequency of the two inverters. This frequency is the working frequency at which the motor drives the inner and outer rotors to rotate. For example, if the frequency difference between the two frequencies is set to be less than 1Hz, start the inner and outer rotors under the state of slight speed difference, and collect acceleration signals and key phase signal.

In step S120, as shown in FIG. 3, feature extraction is performed on the vibration signal to obtain input parameters, which specifically includes the following steps:

S310: Based on the acceleration signal, calculate and obtain the amplitude and phase of the initial unbalanced vibration vector of the inner and outer rotors in the coaxial dual rotor;

S320: When the coaxial dual rotors are in a stopped state, perform retesting operations on the inner and outer rotors respectively;

S330: When the coaxial dual rotors are running, detect the acceleration signal after the test weight is added;

S340: Based on the acceleration signal after adding the test weight, calculate the amplitude and phase of the unbalanced vibration vector of the coaxial dual rotors after adding the test weight.

的幅值和相位。暂停内外转子运行，向内外转子分别加试重，确定所加试重/>

的质量和相位。重新启动微速差状态下的内外转子，测量加试重后的水平和垂直方向的加速度信号，利用ZFFT+FT(细化快速傅里叶变换结合离散傅里叶变换)算法提取出内外转子的频率以及频率对应的加试重后的振动幅值，根据键相信号与位移信号的相位差作为不平衡量的相位，由此得到加试重后转子不平衡振动矢量/>

的幅值和相位。将测量到的内外转子初始不平衡振动矢量/>

及加试重后的不平衡振动矢量/>

作为影响系数法的输入参数，同时输入试重矢量/>

Specifically, when performing feature extraction on the vibration signal, the collected horizontal and vertical acceleration signals are analyzed according to the ZFFT+FT (refined Fast Fourier Transform combined with Discrete Fourier Transform) algorithm, and the internal and external rotors are separated. The frequency and amplitude of the initial unbalanced vibration, according to the phase difference between the key phase signal and the displacement signal as the phase of the unbalanced quantity, thus the initial unbalanced vibration vector

amplitude and phase. Suspend the operation of the inner and outer rotors, add test weights to the inner and outer rotors respectively, and determine the added test weights/>

quality and phase. Restart the inner and outer rotors under the state of slight speed difference, measure the acceleration signals in the horizontal and vertical directions after adding the test weight, and use the ZFFT+FT (refinement fast Fourier transform combined with discrete Fourier transform) algorithm to extract the frequency of the inner and outer rotors And the vibration amplitude corresponding to the frequency after adding the test weight, according to the phase difference between the key phase signal and the displacement signal as the phase of the unbalance, thus obtaining the unbalanced vibration vector of the rotor after adding the test weight />

amplitude and phase. The measured initial unbalanced vibration vector of the inner and outer rotors />

And the unbalanced vibration vector after adding the test weight />

As the input parameter of the influence coefficient method, input the trial weight vector at the same time />

In some embodiments, as shown in FIG. 4, based on the acceleration signal, the magnitude and phase of the initial unbalanced vibration vector of the inner and outer rotors in the coaxial dual rotors are calculated, specifically including the following steps:

S410: Perform windowing processing on the frequency response of the low-pass filter, and use the windowed frequency response to filter the original signal of the acceleration signal to obtain a filtered signal;

S420: Perform complex modulation and frequency shift on the filtered signal to obtain a frequency shifted signal;

S430: Determine the frequency range and the number of spectral lines of the frequency-shifted signal;

S440: Perform a segmented DFT (discrete Fourier transform) operation on the frequency-shifted signal according to the frequency range and the number of spectral lines to obtain a segmented and refined spectrum of the signal;

S450: Calculate and obtain the amplitude and phase of the initial unbalanced vibration vector according to the refined spectrum of the signal segment.

Wherein, the expression of the frequency response after the windowing is:

In the formula, w ₁ is the low cut-off frequency of the complex analysis filter, w ₂ is the high cut-off frequency of the complex analysis filter, _we = (w ₁ + w ₂ )/2, and the complex analysis filter is the The low-pass filter is obtained by complex frequency shifting, H(k) is the frequency response after windowing, H ₀ (k) is the frequency response of the low-pass filter, w is windowing, and w _e is the frequency response of the complex analysis filter Center frequency, j is the imaginary number unit, k=1, 2, ..., N, where N is the number of spectrum analysis points.

Wherein, the expression of described filtering signal is:

x″[n]=x′[n]*H(k),k=M,D+M,...,(N-1)D+M

In the formula, x″[n] is the filtered signal, x′[n] is the signal obtained after sampling the original signal, H(k) is the frequency response after windowing, D is the refinement multiple, and M is Filter half order, N is the number of spectral analysis points.

In principle, in the balance process, the ZFFT+FT (refined Fast Fourier Transform combined with Discrete Fourier Transform) algorithm is used for the acceleration signal (it should be understood that when calculating the initial unbalanced vibration vector, the acceleration signal It is the acceleration signal of the inner and outer rotors collected by the sensor before the test weight is added. When calculating the unbalanced vibration vector after the test weight is added, the acceleration signal is the acceleration signal of the inner and outer rotors after the test weight is collected by the sensor) for analysis The process is:

According to the frequency shift property of Fourier transform, the signal after complex modulation of the original signal x[n] is:

In the formula, f ₀ is the center frequency of the refined frequency band, and f _S is the sampling frequency of the original signal.

Assuming that the frequency response of the low-pass filter is H ₀ (k), perform a complex frequency shift on it to obtain a complex analytical filter, add a window w to the frequency response of the filter to reduce the ripple amplitude, and the frequency after windowing The response can be expressed as:

In the formula, w ₁ is the low cut-off frequency of the complex analysis filter, w ₂ is the high cut-off frequency, and _we = (w ₁ +w ₂ )/2.

Suppose the sampling frequency of the original signal x[n] is f _s , the number of spectral analysis points is N, the refinement multiple is D, and the half-order of the filter is M, perform selective decimation filtering on x[n], determine the position of the selected sampling point, and extract The sampling points form a new signal x′[n], which is filtered, and the signal x″[n] is obtained after filtering as follows:

x″[n]=x′[n]*H(k),k=M,D+M,...,(N-1)D+M

Perform complex frequency shift on x″[n], where f ₀ is the center frequency.

In the above formula, the complex modulated frequency-shifted signal is obtained. For this signal, a further selection is made for the frequency band of interest. First determine the frequency range f _l ~ f _h that needs to be refined. Select a new resolution df, use df as the frequency interval, and divide the frequency range f _l ~ f _h into K frequency spectral lines, the frequency sequence f can be obtained as:

f＝f _l :df:f _h

Next, DFT (Discrete Fourier Transform) operation is performed on the signal x"'[n] in this frequency range, and the obtained spectrum x"'(k) is:

The frequency resolution of the original signal x[n] is Δf=f _s /N, and the frequency resolution of the signal after decimation and filtering is increased by D times, that is, Δf'=f _s /N/D, and then it is DFT (Discrete Fourier Transform) operation, the frequency resolution of the signal is increased to Δf"=mΔf'=m(Δf/D), at this time, the resolution of the obtained spectrum x"'(k) is mΔf', it can be seen that, This method further increases the spectral resolution by m times. Since the value of m is a number between 0 and 1, and the smaller the value of the frequency resolution, the higher the corresponding resolving power, so using ZFFT+FT (refinement Fast Fourier transform combined with discrete Fourier transform) algorithm will get more accurate signal separation frequency and corresponding amplitude.

After obtaining the frequency spectrum x(k) of the vibration signal, the amplitude corresponding to each frequency can be calculated. Since the modulus of the frequency component is N/2 times the corresponding amplitude of the frequency component, the corresponding amplitude of the frequency component should be is 2/N of the modulus value of the frequency component, which is:

A'(k)=|x"'(k)|·2/N

After the DFT (Discrete Fourier Transform) operation, the signal will fall in the positive frequency and negative frequency intervals, and the amplitude components corresponding to the positive frequency and negative frequency are both 1/2 of the real signal amplitude, so the real amplitude of the signal for:

A(k)=2A'(k)

The implementation process of the method provided by the present invention is briefly described below by taking a specific usage scenario as an example.

First, the simulated micro-speed difference beat vibration signal is separated:

Construct the following simulation signal, which is composed of two sinusoidal signals with different frequencies and a noise signal superimposed:

为其各自相位，c[n]为噪声信号。Among them, x[n] is the simulated micro-speed difference signal, f ₁ and f ₂ are the frequencies of the two sinusoidal signals, A ₁ and A ₂ are the amplitudes of the two sinusoidal signals,

For their respective phases, c[n] is the noise signal.

Complex modulation of the original signal x[n]:

In the formula, f ₀ is the center frequency of the refined frequency band, and f _S is the sampling frequency of the original signal.

The frequency response of the low-pass filter is H ₀ (k) for complex frequency shifting, and then windowed w:

In the formula, w ₁ is the low cut-off frequency of the complex analysis filter, w ₂ is the high cut-off frequency, and _we = (w ₁ +w ₂ )/2.

Set the number of spectral analysis points N, the refinement multiple D and the filter half-order M, extract sampling points from x[n] to form a new signal x′[n], filter it, and obtain the signal x″[n] after filtering as follows:

x″[n]=x′[n]*H(k),k=M,D+M,...,(N-1)D+M

Perform complex frequency shift on x″[n], where f ₀ is the center frequency:

Determine the refinement frequency range f _l ~ f _h . Select the new resolution df as the frequency interval, divide the frequency range f _l ~ f _h into K frequency spectral lines, and obtain the frequency sequence f as:

f＝f _l :d _f :f _h

Perform DFT (discrete Fourier transform) operation on the signal of x″’[n] in this frequency range, and the obtained spectrum x″’(k) is:

The amplitude corresponding to the frequency component in the frequency spectrum should be 2/N of the modulus of the frequency component, which is:

A'(k)=|x"'(k)|·2/N

Since the amplitude components corresponding to positive frequency and negative frequency are both 1/2 of the real signal amplitude, the real amplitude of the signal is:

A(k)=2A'(k)

According to the amplitude extraction results of the simulated signal, ZFFT+FT (refined Fast Fourier Transform combined with Discrete Fourier Transform) algorithm is used to analyze the frequency spectrum of the simulated beat vibration signal, and the extracted amplitude error is less than 0.1%.

The specific implementation method of the present invention will be described below by taking the unbalanced vibration signal feature extraction and unbalanced vibration control of a double-rotor test bench with a small speed difference as an example.

1) Install the horizontal and vertical acceleration sensors required for measurement and the eddy current sensors required for measurement of key phase signals on the micro-differential speed double-rotor test bench;

2) Set the rotation speed of the inner rotor and the outer rotor through the serial port software. The difference between the rotation frequency of the inner and outer rotors is 1 Hz. Set the sampling frequency and the number of sampling points, start the inner and outer rotors at the same time, and collect the vibration signal acceleration data;

3) Measure the vibration response of the inner rotor and the vibration response of the outer rotor

4) Add test weights to the inner and outer rotors respectively, and select phases to add test weights at the counterweight plates of the inner and outer rotors

5) Measure the unbalanced vibration response of the inner and outer rotors after adding test weight

为：6) According to the unbalance response of the inner and outer rotors before and after adding the test weight and the mass and phase of the added test weight, calculate the respective influence coefficient and unbalance of the inner rotor and the outer rotor, where the influence coefficient

for:

为：Unbalance

for:

在不平衡量/>

相位的反相方向添加与/>

的模相等的配重块即可完成配重，转子已基本达到平衡状态；7) Finally remove the test weight

In the unbalanced amount />

The inverse direction of the phase is added with the />

The counterweights with equal modules can complete the counterweight, and the rotor has basically reached a balanced state;

8) Measure the vibration response of the balanced inner and outer rotors. According to the comparison between the initial unbalanced vibration response of the inner and outer rotors and the vibration response after the counterweight, the unbalanced vibration of the inner and outer rotors is controlled.

It can be seen from the above embodiments that the present invention can accurately separate the beating vibration signals of the dual-rotors with a small speed difference within 1 Hz, and it is difficult to accurately separate the vibration characteristics of the beating vibration signals of the dual-rotors with a small speed difference by conventional methods. The invention can measure the unbalanced vibration characteristics of the rotor in real time, and overcomes the problem of poor real-time performance of the traditional method. The invention only needs to use the acceleration sensor to measure the signal of the bearing seat to extract the characteristics of the unbalanced vibration signal of the double rotor, and overcomes the difficult problem that it is difficult to install the displacement sensor to measure the signals of the inner and outer rotors separately in special occasions in practical applications. As shown in Figures 5-8, the extraction accuracy of the present invention is significantly better than that of CZT (chirp Z transform) and ZFFT (refined Fast Fourier Transform) extraction methods, and can obtain more accurate data without increasing the data length. High frequency resolution. Under the same data length, the maximum relative error of the ZFFT+FT (refined Fast Fourier Transform combined with Discrete Fourier Transform) algorithm is 1/8 of the maximum relative error of the CZT (Chirp Z Transform) algorithm, which is ZFFT ( 1/5 of the maximum relative error of the thinning fast Fourier transform) algorithm. The field test proves that this method can accurately and effectively identify the unbalance response of the inner and outer rotors of the coaxial dual rotor system with slight speed difference, and can meet the needs of real-time signal monitoring, real-time signal processing and unbalance vibration control.

In the above specific implementation manner, the unbalanced vibration control method of the coaxial dual rotor system provided by the present invention obtains the vibration signal of the coaxial dual rotor, the vibration signal includes the acceleration signal and the key phase signal; Feature extraction to obtain input parameters, the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and the amplitude of the unbalanced vibration vector after adding a test weight to the coaxial dual rotors value and phase; according to the input parameters, the vibration suppression parameter is calculated by using the influence coefficient method, so that the counterweight corresponding to the vibration suppression parameter is added to the counterweight plate of the coaxial double rotor, and the vibration suppression Parameters include mass and phase of the unbalance. In this way, this method uses the algorithm combining ZFFT (refined Fast Fourier Transform) and DFT (Discrete Fourier Transform) to effectively separate the micro-speed beat vibration signal, extract the unbalanced vibration amplitude and phase of the double rotor, and extract As the input parameters of the influence coefficient method, the amplitude and phase of the unbalance are calculated by adding the test weight and counterweighted, so as to achieve the effect of controlling the unbalanced vibration of the micro-speed difference double rotor. The invention solves the technical problem of insufficient extraction accuracy existing in the prior art when separating the beating vibration signals of the double-rotors with slight speed difference, and the extraction accuracy is heavily dependent on the data length.

In addition to the above method, the present invention also provides a coaxial dual rotor system unbalanced vibration control device, as shown in Figure 9, the device includes:

A signal acquisition unit 910, configured to acquire vibration signals of coaxial dual rotors, the vibration signals including acceleration signals and key phase signals;

The signal processing unit 920 is configured to perform feature extraction on the vibration signal to obtain input parameters, the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and the coaxial Amplitude and phase of the unbalanced vibration vector after double rotors plus test weight;

The parameter generating unit 930 is used to calculate the vibration suppression parameters by using the influence coefficient method according to the input parameters, so as to add the counterweight corresponding to the vibration suppression parameters to the counterweight plate of the coaxial double rotor, so that The vibration suppression parameters described above include the mass and phase of the unbalance.

In some embodiments, obtaining vibration signals of coaxial dual rotors specifically includes:

Setting the frequency of the inner rotor and the frequency of the outer rotor in the coaxial double rotor, so that the frequency difference between the inner and outer rotors is less than a preset frequency value, so that the inner and outer rotors are in a state of slight speed difference;

In the state of the slight speed difference, the horizontal acceleration, vertical acceleration and key phase signals of the inner and outer rotors in the starting state are respectively collected.

In some embodiments, feature extraction is performed on the vibration signal to obtain input parameters, specifically including:

Based on the acceleration signal, calculate the amplitude and phase of the initial unbalanced vibration vector of the inner and outer rotors in the coaxial dual rotor;

When the coaxial double rotors are in a stopped state, the test weight operation is performed on the inner and outer rotors respectively;

When the coaxial dual rotors are running, detecting the acceleration signal after the test weight is added;

Based on the acceleration signal after the test weight is added, the amplitude and phase of the unbalanced vibration vector of the coaxial dual rotors after the test weight is added are calculated and obtained.

In some embodiments, based on the acceleration signal, the amplitude and phase of the initial unbalanced vibration vector of the inner and outer rotors in the coaxial dual rotors are calculated, specifically including:

Perform windowing processing on the frequency response of the low-pass filter, and use the frequency response after windowing to filter the original signal of the acceleration signal to obtain a filtered signal;

Complex modulation frequency shifting is performed on the filtered signal to obtain a frequency shifted signal;

determining the frequency range and the number of spectral lines of the frequency-shifted signal;

Performing a segmental DFT (discrete Fourier transform) operation on the frequency-shifted signal according to the frequency range and the number of spectral lines to obtain a segmented and refined spectrum of the signal;

The amplitude and phase of the initial unbalanced vibration vector are obtained by calculating the refined frequency spectrum according to the signal selection.

In some embodiments, the expression of the frequency response after windowing is:

In the formula, w ₁ is the low cut-off frequency of the complex analysis filter, w ₂ is the high cut-off frequency of the complex analysis filter, _we = (w ₁ + w ₂ )/2, and the complex analysis filter is the The low-pass filter is obtained by complex frequency shifting, H(k) is the frequency response after windowing, H ₀ (k) is the frequency response of the low-pass filter, w is windowing, and w _e is the frequency response of the complex analysis filter Center frequency, j is the imaginary number unit, k=1, 2, ..., N, where N is the number of spectrum analysis points.

In some embodiments, the expression of the filtered signal is:

x″[n]=x′[n]*H(k),k=M,D+M,...,(N-1)D+M

In the formula, x″[n] is the filtered signal, x′[n] is the signal obtained after sampling the original signal, H(k) is the frequency response after windowing, D is the refinement multiple, and M is Filter half order, N is the number of spectral analysis points.

In the above specific implementation manner, the unbalanced vibration control device of the coaxial dual rotor system provided by the present invention obtains the vibration signal of the coaxial dual rotor, the vibration signal includes the acceleration signal and the key phase signal; Feature extraction to obtain input parameters, the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and the amplitude of the unbalanced vibration vector after adding a test weight to the coaxial dual rotors value and phase; according to the input parameters, the vibration suppression parameter is calculated by using the influence coefficient method, so that the counterweight corresponding to the vibration suppression parameter is added to the counterweight plate of the coaxial double rotor, and the vibration suppression Parameters include mass and phase of the unbalance. In this way, this method uses the algorithm combining ZFFT (refined Fast Fourier Transform) and DFT (Discrete Fourier Transform) to effectively separate the micro-speed beat vibration signal, extract the unbalanced vibration amplitude and phase of the double rotor, and extract As the input parameters of the influence coefficient method, the amplitude and phase of the unbalance are calculated by adding the test weight and counterweighted, so as to achieve the effect of controlling the unbalanced vibration of the micro-speed difference double rotor. The invention solves the technical problem of insufficient extraction accuracy existing in the prior art when separating the beating vibration signals of the double-rotors with slight speed difference, and the extraction accuracy is heavily dependent on the data length.

FIG. 10 illustrates a schematic diagram of the physical structure of an electronic device. As shown in FIG. 10 , the electronic device may include: a processor (processor) 1010, a communication interface (Communications Interface) 1020, a memory (memory) 1030 and a communication bus 1040, Wherein, the processor 1010 , the communication interface 1020 , and the memory 1030 communicate with each other through the communication bus 1040 . The processor 1010 can invoke logic instructions in the memory 1030 to execute the above method.

In addition, the above-mentioned logic instructions in the memory 1030 may be implemented in the form of software function units and be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes. .

The processor 1010 in the electronic device provided in the embodiment of the present application can call the logic instruction in the memory 1030, and its implementation mode is consistent with the implementation mode of the method provided in the present application, and can achieve the same beneficial effect, and will not be repeated here.

On the other hand, the present invention also provides a computer program product, the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program includes program instructions, and when the program instructions are executed by a computer When executed, the computer can execute the above-mentioned methods.

When the computer program product provided by the embodiment of the present application is executed, the above method is realized, and its specific implementation mode is consistent with the implementation mode described in the embodiment of the foregoing method, and can achieve the same beneficial effect, and will not be repeated here.

In yet another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored, and the computer program is implemented when executed by a processor to perform the above-mentioned methods.

The device embodiments described above are only illustrative, and the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in One place, or it can be distributed to multiple network elements. Part or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. It can be understood and implemented by those skilled in the art without any creative effort.

Those skilled in the art should be aware that, in the above one or more examples, the functions described in the present invention can be implemented by a combination of hardware and software. When software is implemented, the corresponding functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The above specific implementation manners have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation modes of the present invention, and are not used to limit the protection scope of the present invention. On the basis of the technical solution of the present invention, any modification, equivalent replacement, improvement, etc. should be included in the protection scope of the present invention.

Claims (9)

1. A method for controlling unbalanced vibration of a coaxial dual rotor system, characterized in that the method comprises: Acquiring vibration signals of the coaxial dual rotors, the vibration signals including acceleration signals and key phase signals; Perform feature extraction on the vibration signal to obtain input parameters, the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and the coaxial dual rotors after adding a test weight Magnitude and phase of the unbalanced vibration vector; According to the input parameters, the vibration suppression parameters are calculated by using the influence coefficient method, so that the counterweight corresponding to the vibration suppression parameters can be added to the counterweight plate of the coaxial double rotor, and the vibration suppression parameters include the unbalance amount quality and phase. 2. The method for controlling unbalanced vibration of a coaxial dual rotor system according to claim 1, wherein obtaining vibration signals of the coaxial dual rotors specifically includes: Setting the frequency of the inner rotor and the frequency of the outer rotor in the coaxial double rotor, so that the frequency difference between the inner and outer rotors is less than a preset frequency value, so that the inner and outer rotors are in a state of slight speed difference; In the state of the slight speed difference, the horizontal acceleration, vertical acceleration and key phase signals of the inner and outer rotors in the starting state are respectively collected. 3. The method for controlling unbalanced vibration of a coaxial dual-rotor system according to claim 1, wherein the feature extraction is performed on the vibration signal to obtain input parameters, specifically comprising: Based on the acceleration signal, calculate the amplitude and phase of the initial unbalanced vibration vector of the inner and outer rotors in the coaxial dual rotor; When the coaxial double rotors are in a stopped state, the test weight operation is performed on the inner and outer rotors respectively; When the coaxial dual rotors are running, detecting the acceleration signal after the test weight is added; Based on the acceleration signal after the test weight is added, the amplitude and phase of the unbalanced vibration vector of the coaxial dual rotors after the test weight is added are calculated and obtained. 4. The unbalanced vibration control method of the coaxial dual rotor system according to claim 3, characterized in that, based on the acceleration signal, the magnitude of the initial unbalanced vibration vector of the inner and outer rotors in the coaxial dual rotor is calculated and phase, including: Perform windowing processing on the frequency response of the low-pass filter, and use the frequency response after windowing to filter the original signal of the acceleration signal to obtain a filtered signal; Complex modulation frequency shifting is performed on the filtered signal to obtain a frequency shifted signal; determining the frequency range and the number of spectral lines of the frequency-shifted signal; performing a selective discrete Fourier transform operation on the frequency-shifted signal according to the frequency range and the number of spectral lines to obtain a selected and refined spectrum of the signal; The amplitude and phase of the initial unbalanced vibration vector are obtained by calculating the refined frequency spectrum according to the signal selection. 5. The method for controlling unbalanced vibration of a coaxial dual-rotor system according to claim 4, wherein the expression of the frequency response after the windowing is:

In the formula, w ₁ is the low cut-off frequency of the complex analysis filter, w ₂ is the high cut-off frequency of the complex analysis filter, _we = (w ₁ + w ₂ )/2, and the complex analysis filter is the The low-pass filter is obtained by complex frequency shifting, H(k) is the frequency response after windowing, H ₀ (k) is the frequency response of the low-pass filter, w is windowing, and w _e is the frequency response of the complex analysis filter Center frequency, j is the imaginary number unit, k=1, 2, ..., N, where N is the number of spectrum analysis points. 6. The method for controlling unbalanced vibration of a coaxial dual-rotor system according to claim 5, wherein the expression of the filtered signal is: x″[n]=x′[n]*H(k), k=M, D+M, ..., (N-1)D+M In the formula, x″[n] is the filtered signal, x′[n] is the signal obtained after sampling the original signal, H(k) is the frequency response after windowing, D is the refinement multiple, and M is Filter half order, N is the number of spectral analysis points. 7. A coaxial dual-rotor system unbalanced vibration control device, characterized in that the device comprises: a signal acquisition unit, configured to acquire vibration signals of the coaxial dual rotors, the vibration signals including acceleration signals and key phase signals; A signal processing unit, configured to perform feature extraction on the vibration signal to obtain input parameters, the input parameters include the amplitude and phase of the initial unbalanced vibration vector of the coaxial dual rotors, and the coaxial dual rotors The amplitude and phase of the unbalanced vibration vector after the rotor is added with test weight; a parameter generating unit, configured to calculate a vibration suppression parameter by using an influence coefficient method according to the input parameters, so as to add the counterweight corresponding to the vibration suppression parameter to the counterweight plate of the coaxial double rotor, the Vibration suppression parameters include the mass and phase of the unbalance. 8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and operable on the processor, wherein the processor according to claim 1 is implemented when executing the program. to the step of any one of the methods described in 6. 9. A non-transitory computer-readable storage medium, on which a computer program is stored, characterized in that, when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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