A method for joint interference suppression of sound pressure and velocity of array element domain of column barrier under vector circular array

Abstract

The application belongs to the technical field of vector hydrophone, and particularly relates to a kind of column barrier under vector circular array element domain sound pressure vibration velocity joint anti-interference beam forming method, according to the model of vector circular array under cylindrical barrier plate, the element domain sound pressure guiding vector, radial vibration velocity guiding vector and tangential vibration velocity guiding vector are constructed, and then the spatial filtering pretreatment matrix is designed, the output data of vector array is preprocessed;Then use the sound pressure vibration velocity mutual covariance matrix generated by the filtered element domain data of each channel to combine the beam forming of each channel guiding vector, passive detection of target is realized, and the simulation experiment verifies that the achievement can improve the anti-interference ability of vector circular array under cylindrical barrier plate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vector hydrophone, and particularly relates to a method for forming a beam of sound pressure and vibration velocity of a vector circular array element domain under a column barrier. BACKGROUND

[0002] The vector hydrophone can synchronously obtain sound pressure and particle vibration information at the same point, has strong ability to suppress isotropic noise, and has greatly improved performance compared with the traditional sound pressure hydrophone. The vector hydrophone and related processing technology are gradually becoming an important force for passive detection of various sonars. At present, foreign countries have successfully used vector hydrophones in various application backgrounds. In view of the many advantages of the vector hydrophone, domestic related units have carried out related research work on the development of the vector hydrophone and the research of the vector signal processing method, have the ability of designing, manufacturing and calibrating the vector hydrophone, have been well applied in fish finders, underwater acoustic communication and the like, and are now committed to applying the detection advantages of the vector hydrophone to the sonar system installed on a ship carrier to comprehensively improve the passive detection capability of the sonar.

[0003] The sonar array installed on the ship carrier is mostly installed in the bulb bow of the carrier. In order to improve the anti-interference capability of the sonar array, a cylindrical sound barrier is usually installed in the actual engineering. However, the existence of the sound barrier makes the working environment of the vector hydrophone deviate from the free field condition, and changes the application basis of the vector hydrophone. Therefore, the research on the vector signal processing technology under the barrier condition is the key to improving the detection performance of the vector hydrophone when applied to the ship carrier. In view of the application problem of the vector hydrophone under the cylindrical barrier, domestic scholars have discussed the vector sound field characteristics under the cylindrical barrier, analyzed the influence of the barrier on the directivity of the vector hydrophone, and proposed a modal domain vector array azimuth estimation method under the cylindrical barrier, which solves the basic problem of the application of the vector hydrophone under the cylindrical barrier. However, there is still a lack of research on the vector circular array signal processing technology under the cylindrical barrier in complex environments. SUMMARY

[0004] Due to the complex actual working environment of the sonar equipment, strong interference will greatly affect the detection performance of the sonar array. In order to improve the anti-interference performance of the vector array when applied under the cylindrical barrier, the application provides a method for forming a beam of sound pressure and vibration velocity of a vector circular array element domain under a column barrier.

[0005] The specific technical scheme of the application is as follows:

[0006] A method for forming a beam of sound pressure and vibration velocity of a vector circular array element domain under a column barrier, a uniform circular array is installed on the middle surface of the cylindrical barrier, the cylindrical radius is a, the number of vector circular array elements is M, the distance between the hydrophone and the barrier is h, and the target azimuth angle is , and the specific steps are as follows:

[0007] S1, a cylindrical baffle under the vector sound field model is established, and the cylindrical baffle under the sound pressure field expression is:

[0008]

[0009] When the baffle is an absolute hard baffle, When the baffle is an absolute soft baffle, Where j is the imaginary unit, n is the modal order, k is the sound wave number, is the angle between the connecting line of the receiving point and the origin and the x-axis, and the maximum modal order , Indicates the rounding operation, , is the n-th Bessel function, is the n-th first kind Hankel function, is the first order differential of the n-th Bessel function, is the first order differential of the n-th first kind Hankel function;

[0010] The particle velocity field expression under the cylindrical baffle is:

[0011]

[0012]

[0013] Where the above particle velocity has been normalized by the parameter , is the wave impedance in water, and when the baffle is an absolute hard baffle, When the baffle is an absolute soft baffle, ;

[0014] S2, the array element domain sound pressure steering vector, radial velocity steering vector and tangential velocity steering vector are constructed respectively;

[0015] S3, according to the optimal design criterion, the space matrix filter is designed;

[0016] S4, the spatial filter matrix H is used to preprocess the vector circular array element domain data, and the filtered element domain data of each channel is outputted;

[0017] S5, the cross-covariance matrix is generated by using the sound pressure array element domain signal and the tangential velocity array element domain signal, ;

[0018] S6, the beam output energy is calculated by combining the channel steering vector, cross-covariance matrix and cross-covariance matrix .

[0019] Further, in the step S2, the method of constructing the element domain sound pressure steering vector, the element domain radial vibration velocity steering vector and the element domain tangential vibration velocity steering vector is as follows:

[0020] Element domain sound pressure steering vector:

[0021]

[0022] Element domain particle vibration velocity steering vector:

[0023]

[0024]

[0025] Where the angle between the mth element and the x-axis is , The beam steering angle.

[0026] Further, in the step S3, the method of designing the spatial domain matrix filter according to the optimal design criterion is as follows:

[0027] Suppose that the array manifold matrix composed of the passband region steering vectors is Then,

[0028]

[0029] The array manifold matrix composed of the stopband region steering vectors is Then,

[0030]

[0031] And The passband region and the stopband region incident azimuth angle set are P and S respectively, and the number of steering vectors after discretization of the passband region and the stopband region are P and S respectively, The minimum mean square criterion spatial domain matrix filter is selected as the pre-processing filter, and

[0032]

[0033]

[0034] The expression of the spatial domain filter matrix is

[0035]

[0036] Where the superscript H represents the conjugate transpose operation on the matrix, and -1 represents the inverse operation on the matrix.

[0037] Further, in the step S4, the method for pre-processing the vector circular array element domain data by using the spatial filtering matrix H is as follows:

[0038]

[0039] wherein t represents time, is the original element domain time domain data of the vector circular array, is the pre-processed element domain time domain data, is the received time domain data of the sound pressure channel, the radial vibration speed channel and the tangential vibration speed channel respectively, is the pre-processed time domain data of the sound pressure channel, the radial vibration speed channel and the tangential vibration speed channel respectively, T represents the transposition operation on the matrix.

[0040] Further, in the step S5, the method for generating the cross-covariance matrix and the cross-covariance matrix is as follows:

[0041]

[0042] .

[0043] Further, in the step S6, the method for calculating the beam output energy is as follows:

[0044] .

[0045] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0046] According to the vector circular array model under the cylindrical barrier, the present application constructs the element domain sound pressure guide vector, the radial vibration speed guide vector and the tangential vibration speed guide vector, and further designs the spatial filtering pre-processing matrix to realize the pre-processing of the vector array output data; then, the sound pressure vibration cross-covariance matrix is generated by using the filtered element domain data of each channel, the beam forming is performed in combination with the guide vectors of each channel, the passive target detection is realized, and through the simulation experiment verification, the present application can improve the anti-interference ability of the vector circular array under the cylindrical barrier. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is the vector circular array model diagram on the cylindrical barrier of the present application;

[0048] Figure 2 is the flow chart of the present application;

[0049] Figure 3 is the passive target detection result diagram of the vector circular array under the cylindrical barrier in the simulation example of the present application, Figure 3Fig. 2 is a comparison result diagram of spatial spectrum estimation of the (a) in the independent processing of the sound pressure and the vibration velocity of the array element domain of the spatial filter pretreatment front vector array and the joint processing of the sound pressure and the vibration velocity of the array element domain of the vector array before the spatial filter pretreatment, Figure 3 Fig. 2 is a comparison result diagram of spatial spectrum estimation of the (a) in the independent processing of the sound pressure and the vibration velocity of the array element domain of the spatial filter pretreatment front vector array and the joint processing of the sound pressure and the vibration velocity of the array element domain of the vector array before the spatial filter pretreatment, DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments are clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all. Based on the embodiments, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0051] The drawings are combined Figures 1-2 As shown in the drawings, a vector circular array element domain sound pressure and vibration velocity joint anti-jamming beam forming method under a column barrier, a uniform circular array is installed on the middle surface of the cylindrical barrier, the cylindrical radius is a, the number of vector circular array elements is M, the distance between the hydrophone and the barrier is h, and the target azimuth is The specific steps are as follows.

[0052] S1, a vector sound field model under a cylindrical barrier is established, and the sound pressure field expression under the cylindrical barrier is:

[0053]

[0054] When the barrier is an absolute hard barrier, When the barrier is an absolute soft barrier, Where j is the imaginary unit, n is the modal order, k is the sound wave number, is the angle between the connecting line of the receiving point and the origin and the x-axis, and the maximum modal order is , represents the rounding operation, , is the n-order Bessel function, is the n-order first kind Hankel function, is the first-order differential of the n-order Bessel function, is the first-order differential of the n-order first kind Hankel function;

[0055] The particle velocity field expression under the cylindrical barrier is:

[0056]

[0057]

[0058] Where the above particle velocity has been normalized by the parameter ​is the wave impedance in water, and when the barrier is an absolutely hard barrier, ; when the barrier is an absolutely soft barrier, ;

[0059] S2, respectively, construct an array element domain sound pressure steering vector, a radial vibration velocity steering vector and a tangential vibration velocity steering vector;

[0060] S3, design a spatial matrix filter according to an optimal design criterion;

[0061] S4, utilize the spatial filter matrix H to pre-process the vector circular array element domain data, and output filtered element domain data of each channel;

[0062] S5, utilize the sound pressure element domain signal and the tangential vibration velocity element domain signal to generate a cross-covariance matrix , utilize the sound pressure element domain signal and the radial vibration velocity element domain signal to generate a cross-covariance matrix ;

[0063] S6, combine the channel steering vectors, the cross-covariance matrix and the cross-covariance matrix to calculate the beam output energy.

[0064] Specifically, in the step S2, the method of constructing the array element domain sound pressure steering vector, the radial vibration velocity steering vector and the tangential vibration velocity steering vector is as follows:

[0065] Array element domain sound pressure steering vector:

[0066]

[0067] Array element domain particle vibration velocity steering vector:

[0068]

[0069]

[0070] Wherein the included angle between the mth array element and the x-axis is , is the beam steering angle.

[0071] Specifically, in the step S3, the method of designing a spatial matrix filter according to an optimal design criterion is as follows:

[0072] Suppose that the array manifold matrix composed of the passband region steering vectors is , then

[0073]

[0074] The array manifold matrix composed of the stopband region steering vectors is , then

[0075]

[0076] and are the incident azimuth angle sets of the passband region and the stopband region respectively, P and S are the number of steering vectors after discretization of the passband region and the stopband region respectively, , the minimum mean square criterion spatial domain matrix filter is selected as the preprocessing filter, and

[0077]

[0078]

[0079] The expression of the spatial domain filter matrix is

[0080] .

[0081] wherein the superscript H represents the conjugate transpose operation on the matrix, and -1 represents the inverse operation on the matrix.

[0082] Specifically, in the step S4, the method for preprocessing the vector circular array element domain data by using the spatial domain filter matrix H is as follows:

[0083]

[0084] wherein t represents time, is the original element domain time domain data of the vector circular array, is the element domain time domain data after preprocessing, are the received time domain data of the sound pressure channel, the radial vibration velocity channel and the tangential vibration velocity channel respectively, are the time domain data after preprocessing of the sound pressure channel, the radial vibration velocity channel and the tangential vibration velocity channel respectively, T represents the transpose operation on the matrix.

[0085] Specifically, in the step S5, the method for generating the cross-covariance matrix and the cross-covariance matrix is as follows:

[0086]

[0087] .

[0088] Specifically, in the step S6, the method for calculating the beam output energy is as follows:

[0089] .

[0090] The application is described in more detail below with reference to a simulation example:

[0091] Consider a vector circular array with M=15, a cylindrical barrier with a radius a=0.5m, and a uniform vector circular array with a distance h=0.2m from the barrier; the signal frequency is 1000Hz, the incident angle is 200°; the interference frequency is 1000Hz, the incident angle is 30°, the signal-to-noise ratio is 0dB, and the signal-to-interference ratio is 0dB. The minimum mean square criterion is used as the spatial matrix filter design criterion, and the passband angle range is set to [50°, 250°], and the stopband angle range is .

[0092] As shown in the accompanying Figure 3 is the vector circular array target detection result when the cylindrical barrier is an absolute soft barrier, wherein Figure 3 (a) in the accompanying is the comparison result of the spatial spectrum estimation of the sound pressure array element domain, the vector array element domain sound pressure and velocity independent processing, and the vector array element domain sound pressure and velocity joint processing before spatial filtering preprocessing, Figure 3 (b) in the accompanying is the comparison result of the vector array element domain sound pressure and velocity joint processing spatial spectrum estimation before and after spatial filtering preprocessing. As can be seen from Figure 3 (a), when the cylindrical barrier is an absolute soft barrier, the background noise level of the vector array spatial spectrum is significantly lower than that of the sound pressure array spatial spectrum, and the vector circular array element domain sound pressure and velocity joint processing can obtain better background noise suppression capability. As can be seen from Figure 3 (b), after spatial matrix filtering preprocessing, the interference is filtered out, further improving the anti-interference ability of the vector circular array element domain sound pressure and velocity joint processing method under the cylindrical barrier. In summary, the cylindrical barrier under the vector circular array element domain sound pressure and velocity joint anti-interference beamforming method has good anti-interference and noise interference ability.

[0093] The above is only a preferred embodiment of the application, but the protection scope of the application is not limited thereto, and any modification and replacement based on the technical solutions and inventive concepts provided by the application should be covered within the protection scope of the application.

Claims

1. A column barrier under vector circle array element domain sound pressure vibration speed joint anti-interference beam forming method, characterized by: A uniform circular array is installed on the middle surface of the cylindrical barrier, the radius of the cylinder is a, the number of elements of the vector circular array is M, the distance between the hydrophone and the barrier is h, and the target azimuth angle is The specific steps are as follows. S1, a cylindrical barrier under vector sound field model is established, the sound pressure field expression under the cylindrical barrier is: When the baffle is an absolutely hard baffle, When the baffle is an absolutely soft baffle, where j is the imaginary unit, n is the modal order, and k is the acoustic wave number, is the angle between the line connecting the receiving point and the origin and the x-axis, and the maximum modal order , denotes the rounding operation, , is the n-th Bessel function, is the n-th first kind Hankel function, is the first order differential of the n-th Bessel function, is the first order differential of the n-th first kind Hankel function; The particle vibration field expression under the cylindrical barrier is: where the above particle velocity has been expressed by the parameter normalized, is the wave impedance in water, and when the barrier is an absolutely hard barrier, when the barrier is an absolutely soft barrier, ; S2, respectively construct the element domain sound pressure guide vector, the radial vibration velocity guide vector and the tangential vibration velocity guide vector; S3, according to the optimal design criterion, design the space matrix filter; S4, the space filtering matrix H is used to pretreat the vector circle array element domain data, and the filtered element domain data of each channel is outputted; S5, generating a cross-covariance matrix using the sound pressure array element domain signal and the tangential vibration velocity array element domain signal S5, generating a cross-covariance matrix using the sound pressure array element domain signal and the radial vibration velocity array element domain signal ; S6, combine channel steering vectors, cross covariance matrices and cross covariance matrices Calculate beam output energy.

2. The method of claim 1, wherein the method is a method of joint interference suppression of acoustic pressure and velocity for a column below the vector circular array element domain. In the step S2, the method for constructing the element domain sound pressure guide vector, the radial vibration velocity guide vector and the tangential vibration velocity guide vector is as follows: Element domain sound pressure guide vector: Element domain particle vibration guide vector: where θm is the angle between the line connecting the mth array element and the origin and the x-axis , is the beam steering angle.

3. The method of claim 2, wherein the method is a method of joint interference suppression beamforming of acoustic pressure and velocity of the elements of the column below the vector circle array. In the step S3, the method for designing the space matrix filter according to the optimal design criterion is as follows: Assume that the array manifold matrix composed of the passband region steering vectors is then there are The array manifold matrix composed of the stopband region steering vectors is Then, there are and are the incident azimuth angle sets of the passband region and the stopband region, respectively, P and S are the number of steering vectors after discretization of the passband region and the stopband region, respectively, , the minimum mean square criterion spatial matrix filter is selected as the pre-processing filter, and Then the space filtering matrix expression is where the superscripts H represent a conjugate transpose operation on a matrix, and -1 represent an inverse operation on a matrix.

4. The method of claim 3, wherein the method is a method for joint interference suppression of acoustic pressure and velocity of the array element domain of the column below the vector circle array. In the step S4, the method for pretreating the vector circle array element domain data by using the space filtering matrix H is as follows: where t represents time, is the vector circular array original element domain time domain data, is the pretreated element domain time domain data, is the sound pressure channel, radial vibration velocity channel and tangential vibration velocity channel received time domain data respectively, is the sound pressure channel, radial vibration velocity channel and tangential vibration velocity channel pretreated time domain data respectively, T represents the transpose operation on the matrix.

5. The method of claim 4, wherein the method is a method of joint interference suppression beamforming of acoustic pressure and velocity of the elements of the column below the vector circle array. In the step S5, the cross-covariance matrix and the cross-covariance matrix is generated by the following method: 。 6. The method of claim 5, wherein the method is a method of joint interference rejection beamforming of acoustic pressure and velocity for elements of a cylindrical barrier under vector circular array. In the step S6, the method for calculating the beam output energy is as follows: 。

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