A DOA estimation method based on single differential pressure vector hydrophone

Abstract

The application discloses a DOA estimation method based on a single pressure difference type vector hydrophone, sound pressure signals and vibration velocity signals of a sound source are acquired through the single pressure difference type vector hydrophone, and energy envelopes of the sound pressure signals and the vibration velocity signals are obtained; since waveform distortion caused by phase noise does not need to be considered, the algorithm can search for a stable signal energy interval in the received signals which is most suitable for estimating the direction of arrival from the perspective of copying the correlation energy envelope, and the energy of the whole received signal is utilized as much as possible, so that the signal energy utilization rate of the algorithm is improved; and the application further generates a coherent demodulation value by introducing a threshold decision processing mode in communication signal processing based on the calculation of the real parts of cross spectra between channels, so that the advantage of phase noise suppression is achieved, and the shortcoming that the traditional vector DOA method is sensitive to phase noise is overcome; and the application directly calculates the vector amplitude ratio of the vector channels through an observation equation, so that the influence of environmental noise on the direction of arrival estimation is further suppressed.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of underwater acoustic positioning, and particularly relates to a DOA estimation method based on a single differential pressure type vector hydrophone. BACKGROUND

[0002] Underwater acoustic positioning plays an important role in underwater moving target navigation, deep sea oil and gas development and other fields. Currently, underwater acoustic positioning equipment that has been put into large-scale use includes long baseline positioning system, short baseline positioning system and ultra-short baseline positioning system. For small platforms that need to perform underwater cluster cooperation, such as AUV (autonomous underwater vehicle) and UUV (unmanned underwater vehicle), these underwater acoustic positioning equipment more or less have problems of too large volume and weight and difficult deployment. However, with the continuous development of vector hydrophone theory, especially the continuous development of differential pressure type vector hydrophone, a single differential pressure type vector hydrophone with smaller aperture and lighter weight can perform DOA (direction of arrival) estimation and can be easily installed on a small underwater platform.

[0003] In the prior art, due to the manufacturing process of the single differential pressure type vector hydrophone, the concave point of the directivity of the single differential pressure type vector hydrophone is not deep enough, and the phase characteristics of each processing channel in the subsequent signal processing circuit of the single differential pressure type vector hydrophone are inconsistent, so there is inevitably an error when the single differential pressure type vector hydrophone is used for DOA estimation. The traditional average sound intensity algorithm and complex sound intensity algorithm do not take into account these estimation errors, so the demand for high-precision positioning of the target cannot be met when the DOA is estimated. SUMMARY

[0004] To solve the problem that the target cannot be positioned with high precision due to the error when the single differential pressure type vector hydrophone is used for DOA estimation in the prior art, a DOA estimation method based on a single differential pressure type vector hydrophone is provided.

[0005] Step one: obtaining multiple original sound pressure signals emitted by a sound source through a single differential pressure type vector hydrophone, obtaining a sound pressure signal, an X-direction vibration velocity signal and a Y-direction vibration velocity signal at a receiving point according to the multiple original sound pressure signals, and pre-processing the sound pressure signal, the X-direction vibration velocity signal and the Y-direction vibration velocity signal;

[0006] Step two: performing copy correlation on the pre-processed sound pressure signal, the pre-processed X-direction vibration velocity signal and the pre-processed Y-direction vibration velocity signal with a known local reference signal to obtain a sound pressure signal copy correlation waveform, an X-direction vibration velocity signal copy correlation waveform and a Y-direction vibration velocity signal copy correlation waveform; performing cross spectrum on the sound pressure signal copy correlation waveform with the X-direction vibration velocity signal copy correlation waveform and the Y-direction vibration velocity signal copy correlation waveform to obtain coherence demodulation values X PSD and Y PSD ;

[0007] Step three: Hilbert transform is performed on the sound pressure signal copy correlation waveform, the X-direction velocity signal copy correlation waveform and the Y-direction velocity signal copy correlation waveform to obtain a sound pressure signal energy envelope, an X-direction velocity signal energy envelope and a Y-direction velocity signal energy envelope; the X-direction velocity signal energy envelope and the Y-direction velocity signal energy envelope are respectively subjected to twice threshold detection and discrete sampling to obtain an X-direction velocity signal discrete sampling sequence and a Y-direction velocity signal discrete sampling sequence;

[0008] Step four: a peak position Position_x of the X-direction velocity signal discrete sampling sequence and a peak position Position_y of the Y-direction velocity signal discrete sampling sequence are obtained, and a ratio σ x of a Y-direction velocity signal energy envelope value at the Position_x position and an X-direction velocity signal energy envelope value at the Position_x position is calculated y ;

[0009] Step five: whether the ratio σ x or the ratio σ y satisfies a set condition is judged, if yes, the X-direction velocity signal energy envelope and the Y-direction velocity signal energy envelope are intercepted, and an estimated value of a wave direction is calculated through an observation equation according to the intercepted X-direction velocity signal energy envelope, the intercepted Y-direction velocity signal energy envelope, the coherent demodulation value X PSD and the coherent demodulation value Y PSD , if not, an estimated value of a wave direction is calculated through an observation equation according to the X-direction velocity signal discrete sampling sequence, the Y-direction velocity signal discrete sampling sequence, the coherent demodulation value X PSD and the coherent demodulation value Y PSD ; the observation equation is

[0010] wherein is the estimated value of the wave direction, is the Y-direction velocity signal energy envelope, is the X-direction velocity signal energy envelope, N is a half window length, win vy is a Y-direction velocity signal energy envelope intercept window, win vx is an X-direction velocity signal energy envelope intercept window, and M is a point in the intercept window.

[0011] Beneficial effects

[0012] The DOA estimation method based on the single pressure difference type vector hydrophone of the application is based on the system gain brought by the optimal estimation method-copy correlation method under the maximum signal-to-noise ratio criterion, and the DOA (direction of arrival) process of the single pressure difference type vector hydrophone is divided into two parts: copy correlation energy envelope calculation and coherent demodulation value calculation. Since the waveform distortion caused by the phase noise does not need to be considered, the algorithm can find the stable signal energy interval in the received signal that is most suitable for DOA estimation from the perspective of copy correlation energy envelope, and the energy utilization rate of the algorithm is improved as much as possible. Since the method selects the received signal at the directional concave position, whether to intercept the X-direction vibration speed signal energy envelope and the Y-direction vibration speed signal energy envelope is judged according to the ratio σ x and the ratio σ y , and the estimation error caused by the manufacturing process of the pressure difference type vector hydrophone is suppressed. The application further generates the coherent demodulation value by introducing the threshold judgment processing mode in the communication signal processing based on the calculation of the real part of the cross spectrum between channels, and overcomes the disadvantage that the traditional vector DOA method is sensitive to the phase noise. It is possible to use stable signal envelope energy to perform robust DOA estimation without left and right side ambiguity. The application directly calculates the vector amplitude ratio of the vector channel through the observation equation, and further suppresses the influence of environmental noise on DOA estimation. In summary, the application can obtain more robust and reliable time-domain DOA results in the direction of arrival estimation of the single pressure difference type vector hydrophone. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The application is based on the average sound intensity device anechoic tank direction of arrival estimation result of the specific embodiment;

[0014] Figure 2 The application is based on the single pressure difference type vector hydrophone direction of arrival estimation method anechoic tank direction of arrival estimation result of the specific embodiment. DETAILED DESCRIPTION

[0015] Specific embodiment one: the technical solutions of the embodiments of the application will be described below with reference to the accompanying drawings of the embodiments of the application. Figure 1 to the accompanying Figure 2 drawings of the embodiments of the application, which clearly and completely describe the technical solutions in the embodiments of the application:

[0016] Let r be the radius of the single pressure difference type vector hydrophone, k be the cooperative signal wave number, and s(t) be the sound source signal waveform satisfying the far field condition for the pressure difference type vector hydrophone satisfying kr<<1, and the system sampling rate is Fs;

[0017] A DOA estimation method based on a single pressure difference type vector hydrophone, comprising:

[0018] Step one: obtaining the multi-path original sound pressure signals emitted by the sound source through a single differential pressure vector hydrophone, obtaining the sound pressure signal, X-direction velocity signal and Y-direction velocity signal according to the multi-path original sound pressure signals emitted by the sound source, and pre-processing the sound pressure signal, X-direction velocity signal and Y-direction velocity signal;

[0019] Specifically, the sound pressure, X-direction velocity and Y-direction velocity three-path LFM signals of the sound source radiation signals at the receiving point are obtained by the single differential pressure vector hydrophone and pre-processed;

[0020] Step two: copying correlation of the pre-processed sound pressure signal, the pre-processed X-direction velocity signal and the pre-processed Y-direction velocity signal with the known local reference signal to obtain the sound pressure signal copy correlation waveform, the X-direction velocity signal copy correlation waveform and the Y-direction velocity signal copy correlation waveform; cross spectrum of the sound pressure signal copy correlation waveform with the X-direction velocity signal copy correlation waveform and the Y-direction velocity signal copy correlation waveform is performed to obtain the coherent demodulation values X PSD and Y PSD ;

[0021] Specifically, the cross spectrum of the sound pressure channel and the two velocity channel signals is calculated respectively, and the coherent demodulation values are obtained for subsequent judgment of the quadrant where the target direction of arrival is located;

[0022] Step three: Hilbert transform is performed on the sound pressure signal copy correlation waveform, the X-direction velocity signal copy correlation waveform and the Y-direction velocity signal copy correlation waveform to obtain the sound pressure signal energy envelope, the X-direction velocity signal energy envelope and the Y-direction velocity signal energy envelope; the X-direction velocity signal energy envelope and the Y-direction velocity signal energy envelope are respectively subjected to twice threshold detection and discrete sampling to obtain the X-direction velocity signal discrete sampling sequence and the Y-direction velocity signal discrete sampling sequence;

[0023] Step four: obtaining the peak position Position_x of the X-direction velocity signal discrete sampling sequence and the peak position Position_y of the Y-direction velocity signal discrete sampling sequence, calculating the ratio σ x of the Y-direction velocity signal energy envelope value at the Position_x position and the X-direction velocity signal energy envelope value at the Position_x position; and calculating the ratio σ y of the Y-direction velocity signal energy envelope value at the Position_y position and the X-direction velocity signal energy envelope value at the Position_y position;

[0024] Specifically, the threshold of twice threshold detection is calculated according to the sound pressure signal, the X-direction velocity signal and the Y-direction velocity signal, and the envelope energy of the copy correlation waveform is cut off near the first peak value of the threshold.

[0025] Step five: judging the ratio σ x or the ratio σy whether the set condition is satisfied, if yes, intercepting the X-direction velocity signal energy envelope and the Y-direction velocity signal energy envelope, and calculating the estimate value of the wave direction according to the intercepted X-direction velocity signal energy envelope, the intercepted Y-direction velocity signal energy envelope, the coherent demodulation value X PSD and Y PSD calculating the estimate value of the wave direction through the observation equation, if no, calculating the estimate value of the wave direction according to the X-direction velocity signal discrete sampling sequence, the Y-direction velocity signal discrete sampling sequence and the coherent demodulation value X PSD and Y PSD calculating the estimate value of the wave direction through the observation equation; the observation equation is

[0026] wherein is the estimate value of the wave direction, is the Y-direction velocity signal energy envelope, is the X-direction velocity signal energy envelope, N is the half window length, win vy is the Y-direction velocity signal energy envelope intercept window, win vx is the X-direction velocity signal energy envelope intercept window, M is the point in the intercept window.

[0027] Specifically, for the data whose wave direction is near the velocity channel directivity pit, the directivity pit noise suppression of the vector hydrophone is performed to correct the X-direction velocity signal discrete sampling sequence and the Y-direction velocity signal discrete sampling sequence obtained in step three.

[0028] judging whether the ratio σ x or the ratio σ y satisfies the set condition or not; the method for judging whether the ratio σ

[0029] judging whether the ratio σ x or the ratio σ y is less than or equal to the first set value, if yes, the ratio σ x or the ratio σ y satisfies the set condition; if the ratio σ x or the ratio σ y is not less than or equal to the first set value, judging whether the ratio σ x or the ratio σ y is greater than the second set value, if yes, the set condition is satisfied.

[0030] The directional pit suppression range is determined based on the depth of the directional pit of the vector hydrophone. When taking 5° to the left and right of each theoretical pit and calculating the arctangent modulus corresponding to the endpoints of the range, the first setting value is 0.1763 and the second setting value is 5.6713.

[0031] Furthermore, based on the multiple raw sound pressure signals emitted by the sound source, sound pressure signals, X-axis vibration velocity signals, and Y-axis vibration velocity signals are obtained, including:

[0032] The sound pressure signal P(t) is obtained by averaging the multiple original sound pressure signals from the sound source.

[0033]

[0034] X-axis vibration velocity signal

[0035] Y-axis vibration velocity signal

[0036] Where v1(t), v2(t), v3(t) and v4(t) are the four original sound pressure signals, Im(·) represents the imaginary part of the complex number, τ is the integral time delay, and t is the absolute time.

[0037] s(t) is the waveform of the sound source signal received by the single-differential pressure vector hydrophone. and These are the phase differences corresponding to the channels of the differential pressure hydrophone.

[0038] It is known that the sound pressure signal P(t) of the reference signal and the sound source signal are equal in value.

[0039] Furthermore, the sound pressure signal, X-axis vibration velocity signal, and Y-axis vibration velocity signal are preprocessed, including:

[0040] The sound pressure signal P(t), the X-axis vibration velocity signal Vx(t), and the Y-axis vibration velocity signal Vy(t) are synchronized using a windowed copy correlation method to obtain the synchronized sound pressure signal, the synchronized X-axis vibration velocity signal, and the synchronized Y-axis vibration velocity signal.

[0041] A fixed number of signal time periods before the maximum value of the relevant peak are set as the noise sampling interval. The synchronized sound pressure signal, the synchronized X-axis vibration velocity signal, and the synchronized Y-axis vibration velocity signal are truncated according to the noise sampling interval to obtain the truncated sound pressure signal, the truncated X-axis vibration velocity signal, and the truncated Y-axis vibration velocity signal.

[0042] The intercepted sound pressure signal, the intercepted X-axis vibration velocity signal, and the intercepted Y-axis vibration velocity signal are respectively subjected to bandpass filtering to obtain the processed sound pressure signal, the processed X-axis vibration velocity signal, and the processed Y-axis vibration velocity signal.

[0043] Furthermore, the coherent demodulated value X is obtained by cross-spectral analysis of the sound pressure signal copy correlation waveform with the X-axis vibration velocity signal copy correlation waveform and the Y-axis vibration velocity signal copy correlation waveform, respectively. PSD and Y PSD ,include:

[0044] Copy the relevant waveform R of the sound pressure signal. sp (t) Correlation waveforms R with the X-axis velocity signal copy svx (t) and the Y-axis velocity signal copy correlation waveform R svy (t) Perform cross-spectral analysis to obtain the actual value X of the real part of the cross-spectral spectrum at the point where the absolute value of the real part of the cross-spectral spectrum is maximized. PSDmax and Y PSDmax ;

[0045] For X PSDmax and Y PSDmax Perform threshold decision, setting the threshold to zero. Values ​​greater than zero are evaluated with +1, and values ​​less than zero are evaluated with -1. This yields the results compared to X. PSDmax and Y PSDmax The corresponding coherent demodulation value X PSD and Y PSD .

[0046] Furthermore, the energy envelopes of the X-axis and Y-axis vibration velocity signals are subjected to secondary threshold detection and discrete sampling, respectively, to obtain discrete sampling sequences of the X-axis and Y-axis vibration velocity signals, including:

[0047] The first 80% of the noise sampling interval is defined as the noise calculation interval, and the energy envelope of the X-axis vibration velocity signal copy correlation waveform is calculated respectively. The energy envelope of the waveform related to the Y-axis vibration velocity signal copy The maximum value M in the noise calculation interval svx and M svy , the maximum value M svx and M svy The first threshold value is obtained by multiplying the values ​​by a set factor. Second threshold In this embodiment, the multiplier is set to be 5-10 times;

[0048] Based on the first threshold value Second threshold Copy the relevant waveform energy envelope of the X-axis vibration velocity signal respectively. The energy envelope of the waveform related to the Y-axis vibration velocity signal copy Perform secondary threshold detection; extract the X-axis vibration velocity signal and copy the relevant waveform energy envelope. According to the first threshold value the discrete sampling sequence of the energy envelope of the copy correlation waveform of the X-direction velocity signal is obtained from the m points on the left and right of the first peak the energy envelope of the copy correlation waveform of the Y-direction velocity signal is intercepted over the second threshold value the discrete sampling sequence of the energy envelope of the copy correlation waveform of the Y-direction velocity signal is obtained from the m points on the left and right of the first peak

[0049] wherein m is an integer, win vx-z is the energy envelope of the copy correlation waveform of the X-direction velocity signal is intercepted, win vy-z is the energy envelope of the copy correlation waveform of the Y-direction velocity signal is intercepted;

[0050] In the specific embodiment, the value range of m is determined according to the main peak half window length corresponding to the peak value of 3dB.

[0051] Specifically, the embodiment takes the 1215 sampling points in front of the maximum correlation peak as the noise interval.

[0052] Further, whether the X-direction velocity signal energy envelope and the Y-direction velocity signal energy envelope are intercepted is determined according to the ratio σ x and the ratio σ y If yes, the estimated value of the wave direction is calculated through the observation equation according to the intercepted X-direction velocity signal energy envelope, Y-direction velocity signal energy envelope, coherent demodulation value X PSD and Y PSD If no, the estimated value of the wave direction is calculated through the observation equation according to the X-direction velocity signal discrete sampling sequence, Y-direction velocity signal discrete sampling sequence, coherent demodulation value X PSD and Y PSD The calculation of the estimated value of the wave direction through the observation equation includes:

[0053] i is the position in the discrete sampling sequence;

[0054] Whether the ratio σ x or the ratio σ y is less than or equal to the first set value is determined, if yes, the X-direction velocity signal copy correlation waveform energy envelope and the Y-direction velocity signal copy correlation waveform energy envelope are re-intercepted with Position_x as the interception center and n as the half window length according to the intercepted X-direction velocity signal energy envelope, Y-direction velocity signal energy envelope, coherent demodulation value X PSD and Y PSD The estimated value of the wave direction is calculated through the observation equation;

[0055] wherein is the estimated value of the wave direction, is the energy envelope of the Y-direction velocity signal, is the energy envelope of the X-direction velocity signal, win vy-x is the energy envelope of the Y-direction velocity signal re-windowed with Position_x as the center and n as the half window length, win vx-x is the energy envelope of the X-direction velocity signal re-windowed with Position_x as the center and n as the half window length, j is a point in the window, j∈2n+1, n=m.

[0056] If the ratio σ x or the ratio σ y is not less than a first set value, then it is determined whether the ratio σ x or the ratio σ y is greater than a second set value, if yes, then the X-direction velocity signal copy correlation waveform energy envelope and the Y-direction velocity signal copy correlation waveform energy envelope are re-windowed with Position_y as the center and n as the half window length according to the re-windowed X-direction velocity signal energy envelope, the re-windowed Y-direction velocity signal energy envelope, the coherent demodulation value X PSD and Y PSD The estimate value of the wave direction is calculated through an observation equation.

[0057] win vy-y is the energy envelope of the Y-direction velocity signal re-windowed with Position_y as the center and n as the half window length, win vx-y is the energy envelope of the X-direction velocity signal re-windowed with Position_y as the center and n as the half window length, j is a point in the window.

[0058] If the ratio σ x or the ratio σ y is not greater than the second set value, then the X-direction velocity signal discrete sampling sequence, the Y-direction velocity signal discrete sampling sequence, the coherent demodulation value X PSD and Y PSD The estimate value of the wave direction is calculated through an observation equation.

[0059] wherein win vy-z is the energy envelope of the Y-direction velocity signal, win vx-z is the energy envelope of the X-direction velocity signal, m is the half window length of the discrete sampling, and p is a point in the window.

[0060] Specific embodiment two: a computer readable storage medium, the computer readable storage medium stores a computer program, the computer program is read and run by a processor, and the computer program realizes the DOA estimation method based on the single differential pressure type vector hydrophone as described in the specific embodiment one.

[0061] Specific embodiment three: a computer device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to realize the steps of the DOA estimation method based on the single differential pressure type vector hydrophone as described in the specific embodiment one. Specific embodiment:

[0063] Experimental conditions: the sound source radiation signal is a broadband LFM signal of 20kHz to 29kHz, the receiving end is a single differential pressure type vector hydrophone, the sound source and the hydrophone are placed in an anechoic tank, the sound field is placed to meet the far field condition, and the signal to noise ratio is 9dB to 12dB.

[0064] The positions of the transmitting transducer and the receiving differential pressure type vector hydrophone are fixed, the receiving differential pressure type vector hydrophone is rotated at certain angles, the signal is recorded, and multiple groups of data are recorded at the same angle after each rotation, the single vector hydrophone DOA estimation is performed by using the average sound intensity method and the method, the anechoic tank DOA result based on the average sound intensity method is as shown in Figure 1 The anechoic tank DOA result based on the single differential pressure type vector hydrophone DOA estimation method of the present application is as shown in Figure 2 .

[0065] Comparing the two DOA results with the true value and referring to the volatility of the two DOA results, it can be seen that the single differential pressure type vector hydrophone DOA estimation method of the present application is more robust and reliable than the traditional single vector hydrophone average sound intensity method, and the error is smaller.

[0066] Although the present application is described herein with reference to specific embodiments, it should be understood that these examples are merely illustrative of the principles and applications of the present application. It should therefore be understood that numerous modifications can be made to the exemplary embodiments, and that other arrangements can be devised without departing from the spirit and scope of the application as defined in the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways other than the original claims describe. It should also be understood that features described in connection with individual embodiments can be used in other described embodiments.

Claims

1. A DOA estimation method based on single differential pressure vector hydrophone, characterized in that, The method comprises the following steps: Step 1: obtaining multiple original sound pressure signals emitted by a sound source through a single differential vector hydrophone, obtaining a sound pressure signal, an X-direction vibration velocity signal and a Y-direction vibration velocity signal according to the multiple original sound pressure signals emitted by the sound source, and pre-processing the sound pressure signal, the X-direction vibration velocity signal and the Y-direction vibration velocity signal; Step two: copy correlate the pre-processed sound pressure signal, the processed X-direction vibration velocity signal and the processed Y-direction vibration velocity signal with a known local reference signal to obtain a sound pressure signal copy correlation waveform, an X-direction vibration velocity signal copy correlation waveform and a Y-direction vibration velocity signal copy correlation waveform; cross-spectrum the sound pressure signal copy correlation waveform with the X-direction vibration velocity signal copy correlation waveform and the Y-direction vibration velocity signal copy correlation waveform to obtain coherence demodulation values X PSD and Y PSD ; Step 3: performing Hilbert transform on the sound pressure signal copy correlation waveform, the X-direction vibration velocity signal copy correlation waveform and the Y-direction vibration velocity signal copy correlation waveform to obtain a sound pressure signal energy envelope, an X-direction vibration velocity signal energy envelope and a Y-direction vibration velocity signal energy envelope; performing twice threshold detection and discrete sampling on the X-direction vibration velocity signal energy envelope and the Y-direction vibration velocity signal energy envelope to obtain an X-direction vibration velocity signal discrete sampling sequence and a Y-direction vibration velocity signal discrete sampling sequence; Step four: obtain the peak position Position_x of the X-direction vibration velocity signal discrete sampling sequence and the peak position Position_y of the Y-direction vibration velocity signal discrete sampling sequence, and calculate the ratio σ of the Y-direction vibration velocity signal energy envelope value at Position_x position and the X-direction vibration velocity signal energy envelope value at Position_x position x ; calculate the ratio σ of the Y-direction vibration velocity signal energy envelope value at Position_y position and the X-direction vibration velocity signal energy envelope value at Position_y position y ; Step five: judging whether the ratio σ x or the ratio σ y meets the set condition, if yes, intercepting the X-direction vibration signal energy envelope and the Y-direction vibration signal energy envelope, and calculating the estimate value of the wave direction according to the intercepted X-direction vibration signal energy envelope, the intercepted Y-direction vibration signal energy envelope, the coherent demodulation value X PSD and Y PSD , if no, calculating the estimate value of the wave direction according to the X-direction vibration signal discrete sampling sequence, the Y-direction vibration signal discrete sampling sequence, the coherent demodulation value X PSD and Y PSD ; the observation equation is wherein is the estimate value of the wave direction, is the Y-direction vibration signal energy envelope, is the X-direction vibration signal energy envelope, N is the half window length, win vy is the Y-direction vibration signal energy envelope intercepting window, win vx is the X-direction vibration signal energy envelope intercepting window, and M is the point in the intercepting window.

2. The DOA estimation method based on single differential pressure vector hydrophone according to claim 1, characterized in that: The method comprises the following steps: Step 1: obtaining multiple original sound pressure signals emitted by a sound source through a single differential vector hydrophone, obtaining a sound pressure signal, an X-direction vibration velocity signal and a Y-direction vibration velocity signal according to the multiple original sound pressure signals emitted by the sound source, and pre-processing the sound pressure signal, the X-direction vibration velocity signal and the Y-direction vibration velocity signal; X-direction vibration velocity signal Y-directional vibration velocity signal Wherein, v1(t), v2(t), v3(t) and v4(t) are four original sound pressure signals, Im(·) represents the imaginary part in a complex number, τ is an integral time delay, and t is an absolute time.

3. The DOA estimation method based on single differential pressure vector hydrophone according to claim 2, characterized in that: The method comprises the following steps: Step 2: performing signal synchronization on the sound pressure signal P(t), the X-direction vibration velocity signal Vx(t) and the Y-direction vibration velocity signal Vy(t) through a windowed copy correlation method to obtain a synchronized sound pressure signal, a synchronized X-direction vibration velocity signal and a synchronized Y-direction vibration velocity signal; Step 3: setting a fixed number of signal periods in front of a maximum correlation peak as a noise sampling interval, and cutting the synchronized sound pressure signal, the synchronized X-direction vibration velocity signal and the synchronized Y-direction vibration velocity signal according to the noise sampling interval to obtain a cut sound pressure signal, a cut X-direction vibration velocity signal and a cut Y-direction vibration velocity signal; Step 4: performing band-pass filtering on the cut sound pressure signal, the cut X-direction vibration velocity signal and the cut Y-direction vibration velocity signal to obtain a processed sound pressure signal, a processed X-direction vibration velocity signal and a processed Y-direction vibration velocity signal.

4. The DOA estimation method based on single differential pressure vector hydrophone according to claim 3, characterized in that: The cross spectrum of the sound pressure signal copy correlation waveform and the X-direction vibration velocity signal copy correlation waveform and the cross spectrum of the sound pressure signal copy correlation waveform and the Y-direction vibration velocity signal copy correlation waveform are obtained to obtain coherent demodulation values X and Y PSD and Y PSD , comprising: Copy the sound pressure signal correlation waveform R sp (t) with the X-direction vibration velocity signal copy correlation waveform R svx (t) and the Y-direction vibration velocity signal copy correlation waveform R svy (t) to obtain the cross spectrum real part actual value X PSDmax and Y PSDmax at the maximum cross spectrum real part absolute value; X PSDmax and Y PSDmax decision, threshold set to zero, greater than zero decision is +1, less than zero decision is -1 to get the corresponding coherent demodulation values X PSDmax and Y PSDmax X PSD and Y PSD .

5. The DOA estimation method based on single differential pressure vector hydrophone according to claim 4, characterized in that: The method comprises the following steps: A portion of the noise sampling interval is defined as the noise calculation interval, and the energy envelope of the X-axis vibration velocity signal copy correlation waveform is calculated respectively. The energy envelope of the waveform related to the Y-axis vibration velocity signal copy The maximum value M in the noise calculation interval svx and M svy , the maximum value M svx and M svy The first threshold value is obtained by multiplying the values ​​by a set factor. Second threshold Based on the first threshold value Second threshold Copy the relevant waveform energy envelope of the X-axis vibration velocity signal respectively. The energy envelope of the waveform related to the Y-axis vibration velocity signal copy Perform secondary threshold detection; extract the X-axis vibration velocity signal and copy the relevant waveform energy envelope. According to the first threshold value The discrete sampling sequence of the energy envelope of the Be-correlation waveform of the X-direction vibration velocity signal is obtained from m points to the left and right of the first peak. Extract the Y-axis vibration velocity signal and copy the relevant waveform energy envelope. Passing the second threshold The discrete sampling sequence of the energy envelope of the Y-axis vibration velocity signal copy correlation waveform is obtained from m points to the left and right of the first peak. Wherein, m is an integer, and win is a cut window.

6. The DOA estimation method based on single differential pressure vector hydrophone according to claim 5, characterized in that: According to the ratio σ x and the ratio σ y determine whether to intercept the X-direction velocity signal energy envelope and the Y-direction velocity signal energy envelope; if yes, then according to the intercepted X-direction velocity signal energy envelope, the Y-direction velocity signal energy envelope, the coherent demodulation value X PSD and Y PSD calculate the estimate value of the wave direction through the observation equation, if not, then according to the X-direction velocity signal discrete sampling sequence, the Y-direction velocity signal discrete sampling sequence, the coherent demodulation value X PSD and Y PSD calculate the estimate value of the wave direction through the observation equation, The computer readable storage medium stores a computer program, and when the computer program is read and run by a processor, the method for estimating DOA based on a single differential vector hydrophone according to any one of claims 1 to 6 is realized. i is the position within the discrete sampled sequence; judging whether the ratio σ x or the ratio σ y is less than or equal to a first set value, if yes, re-cutting the copy correlated waveform energy envelope of the X-direction vibration signal with Position_x as the cutting center and n as the half window length and the copy correlated waveform energy envelope of the Y-direction vibration signal According to the cut X-direction vibration signal energy envelope, Y-direction vibration signal energy envelope, coherent demodulation value X PSD and Y PSD The estimated value of the wave direction is calculated by the observation equation. wherein is a wave direction estimation value, is a Y-direction vibration signal energy envelope, is an X-direction vibration signal energy envelope, win vy-x is a Y-direction vibration signal energy envelope window re-cut with Position_x as the center and n as the half window length, win vx-x is an X-direction vibration signal energy envelope window re-cut with Position_x as the center and n as the half window length, j is a point in the window, j∈2n+1, n=m; If the ratio σ x or the ratio σ y is not less than or equal to a first set value, then it is determined whether the ratio σ x or the ratio σ y is greater than a second set value, and if so, the Position_y is the center of the intercept, and n is the half-window length to re-intercept the X-direction velocity signal copy correlation waveform energy envelope and the Y-direction velocity signal copy correlation waveform energy envelope According to the intercepted X-direction velocity signal energy envelope, Y-direction velocity signal energy envelope, coherent demodulation values X PSD and Y PSD The estimated value of the wave direction is calculated by the observation equation. win vy-y is the energy envelope intercept window of the Y direction velocity signal re-intercepted with Position_y as the intercept center and n as the half window length vx-y is the energy envelope intercept window of the X direction velocity signal re-intercepted with Position_y as the intercept center and n as the half window length, and j is the point in the intercept window if the ratio σ x or the ratio σ y is not greater than a second set value, then the coherent demodulation values X PSD and Y PSD of the discrete sampling sequence of the X-direction vibration velocity signal and the Y-direction vibration velocity signal are calculated by an observation equation to calculate an estimated value of the wave direction; where win vy-z is the Y-direction velocity signal energy envelope sampling window, win vx-z is the X-direction velocity signal energy envelope sampling window, m is the discrete sampling half-window length, and p is the point within the sampling window.

7. A computer-readable storage medium, characterized in that: The processor executes the computer program to realize the steps of the method for estimating DOA based on a single differential vector hydrophone according to any one of claims 1 to 6.

8. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, ​

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