Disclosure of Invention
The embodiment of the invention provides a signal processing method and device, which at least solve the problem of turbulent flow response signal analysis in a flutter test flight test due to the prior art in the related art.
According to one aspect of the embodiment of the invention, a signal processing method is provided, which comprises the steps of calculating a power spectrum density function matrix according to an acquired multi-channel turbulence response signal, acquiring a maximum singular value curve according to the power spectrum density function matrix, acquiring a self-power spectrum density function of a single-degree-of-freedom system according to the maximum singular value curve, and acquiring modal parameters of the single-mode system according to the self-power spectrum density function.
Optionally, obtaining the power spectrum density function matrix according to the obtained multi-channel turbulence response signal comprises performing power spectrum analysis on the multi-channel turbulence response signal to obtain a power spectrum density function matrix corresponding to each signal in the multi-channel turbulence response signal, wherein the power spectrum density function matrix is an autocorrelation power spectrum density function matrix or a cross correlation power spectrum density function matrix corresponding to each signal.
Further, optionally, obtaining the maximum singular value curve according to the power spectral density function matrix includes performing singular value decomposition on the power spectral density function matrix at each frequency point based on frequency domain orthogonality to obtain the maximum singular value curve of each frequency band.
Optionally, the method further comprises the step of carrying out singular value decomposition on the power spectrum density function matrix at each frequency point based on frequency domain orthogonality to obtain a left singular value vector corresponding to each frequency point, wherein the left singular value vector represents the mode shape of the system.
Further, optionally, obtaining the self-power spectral density function of the single degree of freedom system according to the maximum singular value curve comprises analyzing the left singular value vector based on a modal shape coherence criterion to obtain the self-power spectral density function of the single degree of freedom system of the corresponding frequency.
Optionally, obtaining the modal parameters of the single-mode system according to the self-power spectral density function comprises performing frequency domain fitting on the self-power spectral density function through an orthogonal polynomial, and performing modal parameter estimation on the single-degree-of-freedom system through polynomial fitting to obtain the modal parameters of the single-mode system, wherein the modal parameters of the single-mode system comprise frequency and damping of the single-degree-of-freedom system.
According to another aspect of the embodiment of the invention, a signal processing device is provided, which comprises a signal processing module, a first acquisition module, a second acquisition module and a third acquisition module, wherein the signal processing module is used for calculating a power spectrum density function matrix according to an acquired multi-channel turbulence response signal, the first acquisition module is used for acquiring a maximum singular value curve according to the power spectrum density function matrix, the second acquisition module is used for acquiring a self-power spectrum density function of a single-degree-of-freedom system according to the maximum singular value curve, and the third acquisition module is used for acquiring modal parameters of the single-mode system according to the self-power spectrum density function.
Optionally, the signal processing module comprises a signal processing unit, a power spectrum analysis unit and a power spectrum analysis unit, wherein the signal processing unit is used for carrying out power spectrum analysis on the multi-channel turbulence response signals to obtain a power spectrum density function matrix corresponding to each signal in the multi-channel turbulence response signals, and the power spectrum density function matrix is an autocorrelation power spectrum density function matrix or a cross correlation power spectrum density function matrix corresponding to each signal.
Further, the first acquisition module comprises a first acquisition unit, a second acquisition unit and a third acquisition unit, wherein the first acquisition unit is used for carrying out singular value decomposition on the power spectrum density function matrix at each frequency point based on frequency domain orthogonality to obtain a maximum singular value curve of each frequency band.
Optionally, the first acquisition module further comprises a decomposition unit, which is used for carrying out singular value decomposition on the power spectrum density function matrix at each frequency point based on frequency domain orthogonality to obtain a left singular value vector corresponding to each frequency point, wherein the left singular value vector represents the mode shape of the system.
According to the embodiment of the invention, a power spectrum density function matrix is calculated according to the acquired multi-channel turbulence response signals, a maximum singular value curve is acquired according to the power spectrum density function matrix, a self-power spectrum density function of a single-degree-of-freedom system is acquired according to the maximum singular value curve, and a modal parameter of the single-mode system is acquired according to the self-power spectrum density function. That is, the embodiment of the invention can solve the problem of turbulent flow response signal analysis in the flutter test flight test in the related technology, achieves the technical effects of improving the accuracy of modal parameter estimation and avoiding the defect of calculation instantaneity caused by a random subspace method.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and in the drawings are used for distinguishing between different objects and not for limiting a particular order.
In the related art, for the frequency domain decomposition method and the processing of the turbulent flow response signal of the flutter test, the following signal processing methods mainly exist:
According to a traditional frequency domain decomposition method, a self-power spectrum density function of a single-degree-of-freedom system is calculated by carrying out frequency domain decomposition based on a modal coherence criterion, a single-degree-of-freedom time domain impulse response is calculated by interpolation and zero padding and then carrying out inverse Fourier transformation, and modal parameter estimation is carried out;
Aiming at the turbulent flow response signal analysis of the flutter test, generally, in the wind tunnel test, the turbulent flow response signal is processed through a random decrement technology because the test speed is closer to the flutter boundary, so as to obtain free attenuation response, and then time domain modal parameter estimation is carried out;
aiming at the situation that test data in flutter test flight is far lower than flutter speed and the interference of atmospheric turbulence is large, the modal parameter estimation of the turbulence response signal is carried out by a random subspace method.
However, the above signal processing schemes have better effects under certain technical conditions, but have certain technical defects as well:
in the traditional frequency domain decomposition method, the effect of calculating the time domain impulse response signal by the inverse Fourier transform is poor aiming at the inverse Fourier transform of the self-power spectrum of the single-degree-of-freedom system due to the problem of spectral line density, and the influence on the fitting result is larger;
aiming at the problems of random decrement technology commonly used in flutter wind tunnel test, such as atmospheric turbulence, principle flutter boundary and the like in flutter test flight, the error of the free attenuation response signal calculated by the technology is larger, and the effect of estimating the modal parameters of the flutter test flight is poorer;
The random subspace method has better performance on the modal parameter estimation of the flutter test flight, but in order to obtain a better estimation result, the subspace method obtains a large number of modal parameters through the modal parameter estimation of different orders, and the steady-state pattern method is based on the steady-state pattern method for identifying the steady mode, and the signal processing method has higher time requirements and is a larger defect in practical engineering application.
Therefore, the signal processing method provided by the embodiment of the application aims at the turbulent flow response signal of the flutter test, improves the traditional frequency domain decomposition method, directly carries out the modal parameter estimation of the orthogonal polynomial in the frequency domain, directly carries out the modal parameter estimation in the frequency domain, can better avoid estimation errors caused by insufficient spectral line density, improves the result of the modal parameter estimation, and only needs to obtain the self-power spectral density function of the system according to the technical route of the modal parameter estimation of the turbulent flow response signal of the flutter test, thereby obtaining the modal parameter result of the system by fitting in the frequency domain based on the scheme.
Specifically, according to an aspect of the embodiment of the present application, a signal processing method is provided, and fig. 1 is a schematic flow chart of the signal processing method provided by the embodiment of the present application. As shown in fig. 1, the signal processing method provided by the embodiment of the application includes:
step S102, calculating a power spectral density function matrix according to the acquired multi-channel turbulence response signals;
Optionally, the step S102 of calculating the power spectrum density function matrix according to the acquired multi-channel turbulence response signals includes performing power spectrum analysis on the multi-channel turbulence response signals to obtain a power spectrum density function matrix corresponding to each signal in the multi-channel turbulence response signals, where the power spectrum density function matrix is an autocorrelation power spectrum density function matrix or a cross correlation power spectrum density function matrix corresponding to each signal.
Specifically, fig. 2 is a schematic flow chart of another signal processing method provided by the embodiment of the present application, as shown in fig. 2, in the embodiment of the present application, power spectrum analysis is performed on a multi-channel turbulence response signal to obtain a self (mutual) correlation power spectrum density function matrix of the corresponding signal, and the multi-channel turbulence response signal obtains the power spectrum density function matrix through a periodic chart method.
Step S104, obtaining a maximum singular value curve according to a power spectrum density function matrix;
Optionally, the step S104 of obtaining the maximum singular value curve according to the power spectrum density function matrix includes performing singular value decomposition on the power spectrum density function matrix at each frequency point based on frequency domain orthogonality to obtain the maximum singular value curve of each frequency band.
Optionally, the signal processing method provided by the embodiment of the application further comprises the step of carrying out singular value decomposition on the power spectrum density function matrix at each frequency point based on frequency domain orthogonality to obtain a left singular value vector corresponding to each frequency point, wherein the left singular value vector represents the mode shape of the system.
Specifically, as shown in fig. 2, based on frequency domain orthogonality, singular value decomposition is performed on the power spectrum density function matrix at each frequency point to obtain a maximum singular value curve of each frequency band and a left singular value vector corresponding to each frequency point, and based on the power spectrum density function matrix obtained in step S102, the maximum singular value curve is obtained through singular value decomposition (Singular Value Decomposition).
Step S106, obtaining a self-power spectral density function of the single degree of freedom system according to the maximum singular value curve;
Optionally, the step S106 of obtaining the self-power spectral density function of the single degree of freedom system according to the maximum singular value curve comprises analyzing the left singular value vector based on the mode shape coherence criterion to obtain the self-power spectral density function of the single degree of freedom system with corresponding frequency.
Specifically, as shown in fig. 2, the left singular value vector in step S104 represents the mode shape of the system, the left singular value vector is analyzed based on the mode shape coherence criterion to obtain a self-power spectral density function of the single degree of freedom system with corresponding frequency, and the maximum singular value curve obtained in step S104 is based on the mode frequency to be analyzed to obtain the self-power spectral density function of the single degree of freedom system according to the mode amplitude coherence condition.
Step S108, obtaining the modal parameters of the single-mode system according to the self-power spectral density function.
Optionally, obtaining the modal parameters of the single-mode system according to the self-power spectral density function in step S108 includes performing frequency domain fitting on the self-power spectral density function through an orthogonal polynomial, and performing modal parameter estimation on the single-degree-of-freedom system through polynomial fitting to obtain the modal parameters of the single-mode system, wherein the modal parameters of the single-mode system include frequency and damping of the single-degree-of-freedom system.
Specifically, as shown in fig. 2, the frequency domain fitting is performed on the self-power spectral density function of the single-degree-of-freedom system obtained in step S106 through an orthogonal polynomial, and the modal parameter estimation is directly performed on the single-degree-of-freedom system through polynomial fitting, so that the frequency and the damping of the single-degree-of-freedom system are finally obtained.
In summary, the signal processing method provided by the embodiment of the application aims at the turbulent flow response signal analysis in the flutter test flight, can improve the accuracy of modal parameter estimation, and simultaneously avoids the problem of insufficient calculation instantaneity caused by a random subspace method.
According to the embodiment of the invention, a power spectrum density function matrix is calculated according to the acquired multi-channel turbulence response signals, a maximum singular value curve is acquired according to the power spectrum density function matrix, a self-power spectrum density function of a single-degree-of-freedom system is acquired according to the maximum singular value curve, and a modal parameter of the single-mode system is acquired according to the self-power spectrum density function. That is, the embodiment of the invention can solve the problem of turbulent flow response signal analysis in the flutter test flight test in the related technology, achieves the technical effects of improving the accuracy of modal parameter estimation and avoiding the defect of calculation instantaneity caused by a random subspace method.
According to another aspect of the embodiment of the present invention, a signal processing apparatus is provided, and fig. 3 is a schematic diagram of the signal processing apparatus provided in the embodiment of the present invention. As shown in fig. 3, the system comprises a signal processing module 32 for calculating a power spectrum density function matrix according to the acquired multi-channel turbulence response signal, a first acquisition module 34 for acquiring a maximum singular value curve according to the power spectrum density function matrix, a second acquisition module 36 for acquiring a self-power spectrum density function of the single-degree-of-freedom system according to the maximum singular value curve, and a third acquisition module 38 for obtaining a modal parameter of the single-mode system according to the self-power spectrum density function.
Optionally, the signal processing module 32 includes a signal processing unit, configured to perform power spectrum analysis on the multi-channel turbulence response signal, to obtain a power spectrum density function matrix corresponding to each signal in the multi-channel turbulence response signal, where the power spectrum density function matrix is an autocorrelation power spectrum density function matrix or a cross correlation power spectrum density function matrix corresponding to each signal.
Further, the first obtaining module 34 may optionally include a first obtaining unit, configured to perform singular value decomposition on the power spectrum density function matrix at each frequency point based on the orthogonality of the frequency domains, so as to obtain a maximum singular value curve of each frequency band.
Optionally, the first obtaining module 34 further includes a decomposition unit, configured to perform singular value decomposition on the power spectrum density function matrix at each frequency point based on the frequency domain orthogonality, to obtain a left singular value vector corresponding to each frequency point, where the left singular value vector represents a mode shape of the system.
Further, optionally, obtaining the self-power spectral density function of the single degree of freedom system according to the maximum singular value curve comprises analyzing the left singular value vector based on a modal shape coherence criterion to obtain the self-power spectral density function of the single degree of freedom system of the corresponding frequency.
Optionally, obtaining the modal parameters of the single-mode system according to the self-power spectral density function comprises performing frequency domain fitting on the self-power spectral density function through an orthogonal polynomial, and performing modal parameter estimation on the single-degree-of-freedom system through polynomial fitting to obtain the modal parameters of the single-mode system, wherein the modal parameters of the single-mode system comprise frequency and damping of the single-degree-of-freedom system.
The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention.