Sparse combination array measurement system and method for underwater target radiation noise measurement, program and storage medium

Abstract

The invention belongs to the technical field of underwater target radiation noise measurement, and particularly relates to a sparse combination array measurement system and method for underwater target radiation noise measurement, a program and a storage medium. A sparse combined array formed by a sound pressure spiral double-cone volume array with a sparse structure and a sound pressure vector nested vertical linear array is designed, a combined array frequency-division testing scheme of a high-frequency volume array and a low-frequency vertical linear array is adopted, a combined measurement method of a sound pressure hydrophone and a vector hydrophone is utilized, a measurement frequency band is extended, and the measurement precision is improved. And effective measurement of the full-band radiation noise of the underwater target is realized. Through a sparse array arrangement structure and an improved constant-beam-width beam forming method, a two-dimensional steady constant-beam-width beam is obtained while the number of array elements is reduced and the array complexity is reduced, and an appropriate main lobe width and a lower side lobe level can be adjusted according to a measured target and a measurement distance. According to the method, the array element redundancy of the measurement array is reduced, and the method can be flexibly applied to various application scenes of underwater radiation noise measurement.

Description

Technical Field

[0001] The present invention belongs to the technical field of underwater target radiation noise measurement, and in particular relates to a sparse combination array measurement system, method, program and storage medium for underwater target radiation noise measurement. Background Art

[0002] With the development of vibration reduction and noise reduction technology, the radiated noise level of underwater targets has gradually decreased. How to accurately evaluate the radiated noise level of underwater targets has become a difficult problem. The underwater target radiated noise measurement system has gradually developed from the traditional single sound pressure hydrophone and multi-hydrophone measurement system to the linear array and volume array measurement system. The single sound pressure hydrophone measurement system commonly used in engineering has a simple configuration, but it is seriously affected by multi-path interference and cannot meet the measurement signal-to-noise ratio requirements for low-noise target radiated noise. The use of multiple sound pressure hydrophones to form a vertical linear array of hydrophones may reduce the influence of sea surface noise and channel multi-path interference, but the vertical linear array has no horizontal directivity and the measurement gain is low; at the same time, the array aperture required for low-frequency band testing is large, which is limited by the depth of the water body, making it difficult to deploy and the formation difficult to control. The use of a volume array system for radiated noise measurement can simultaneously obtain horizontal and vertical directivity. Compared with the commonly used cylindrical volume array, the spiral biconical volume array has a wider horizontal main lobe width and a narrower vertical main lobe width. It can ensure that the target radiating surface is within the main lobe of the beam while suppressing the interference of interface reflection. It has a high measurement gain, but there are problems such as the difficulty of deployment and implementation due to the large number of array elements and the large size of the low-frequency array base.

[0003] In recent years, the successful development and engineering practice of high-reliability and high-sensitivity vector hydrophones have provided new ideas for solving the problem of low-frequency radiated noise measurement. On the one hand, vector hydrophones can form unilateral directivity and obtain horizontal and vertical spatial processing gains; on the other hand, they can obtain additional coherent signal processing gains through the joint processing technology of sound pressure and vibration velocity. Therefore, the vector hydrophone array can ensure a large measurement gain while the array aperture is small. However, as the number of array elements of the vector hydrophone array increases, the system complexity increases significantly, and the system robustness decreases sharply, which is not conducive to the accurate and reliable measurement of underwater target radiated noise. In addition, since the underwater target radiated noise is a wide-band signal, the main lobe width of conventional beamforming changes with frequency. If the main lobe width is too wide or too narrow, it will affect the accuracy of underwater target radiated noise measurement. Therefore, in broadband array signal processing, the constant beamwidth beamforming method is often used to obtain a constant width beam main lobe, so that the spectrum characteristics of the array system to the receiving response output remain unchanged, and a high broadband measurement gain is stably obtained. Summary of the invention

[0004] The object of the present invention is to provide a sparse combination array measurement system, method, program and storage medium for underwater target radiated noise measurement.

[0005] A sparse combination array comprises a sound pressure spiral double cone volume array and a sound pressure vector nested vertical line array; the sound pressure spiral double cone volume array is a cylindrical array with a fixed bottom circular ring, and the top circle is obtained by rotating a certain angle around the cylindrical axis; the cylindrical array comprises a plurality of groups of single sparse line arrays with the same number of array elements evenly arranged on the circumference; the single sparse line array adopts a cross-octave sparse nested array, and the sound pressure vector nested vertical line array adopts a 2-octave sparse nested array, the sound pressure vector nested vertical line array passes through the center of the sound pressure spiral double cone volume array, the central array element of the sound pressure vector nested vertical line array is located at the center of the circular cross-section with the smallest radius of the sound pressure spiral double cone volume array, and the central array element of the sound pressure spiral double cone volume array and the central array element of the sound pressure vector nested vertical line array are in the same plane.

[0006] Furthermore, the sound pressure spiral double cone volume array includes M1 single sparse line arrays with N1 array elements; the single sparse line array consists of M2 single sparse line arrays with N1 array elements. Tl The uniform sound pressure subarrays are concentrically nested, and the array element spacings in each uniform sound pressure subarray are d1,3d1,9d1,..., 2≤M2≤4;

[0007] The sound pressure vector nested vertical linear array consists of M3 array elements with N L The uniform sub-arrays are concentrically nested, and the element spacings in each uniform sub-array are d2, 4d2, 16d2, ..., Some uniform subarrays are combined sound pressure vector arrays, and the number of vector array elements in the combined sound pressure vector array is M. v ;2≤M3≤4.

[0008] A system for measuring radiated noise of underwater targets with a sparse combination array comprises a wet-end test platform and a dry-end data processing device, which are connected by a signal transmission optoelectronic composite cable; the wet-end test platform comprises a sparse combination array, an underwater navigation and positioning array, a depth sensor, an electronic instrument cabin, a pressure-stabilizing instrument cabin, and a float-swivel-weight mooring system; the float-swivel-weight mooring system comprises a main float, a secondary float, a mechanical swivel, an optoelectronic slip ring, a releaser, and an anchor block;

[0009] The acoustic pressure spiral double cone volume array is installed in the array frame, the upper end of the array frame is connected to the first intermediate transition mooring piece through a cable, and the lower end of the array frame is connected to the second intermediate transition mooring piece through a cable; the underwater navigation positioning base array is installed on the top of the array frame, and the electronic instrument cabin is installed at the bottom of the array frame, and a posture sensor, a signal conditioning module and a data acquisition control module are arranged inside the electronic instrument cabin; the first intermediate transition mooring piece is connected to the upper end of the acoustic pressure spiral double cone volume array, and the second intermediate transition mooring piece is connected to the lower end of the acoustic pressure spiral double cone volume array, and a depth sensor and a posture sensor are arranged inside the first intermediate transition mooring piece and the second intermediate transition mooring piece, and the first intermediate transition mooring piece and the second intermediate transition mooring piece transmit upward and downward pulling forces respectively, so that the acoustic pressure spiral double cone volume array is arranged vertically and ensures that its central array element and the central array element of the acoustic pressure vector nested vertical linear array are in the same plane;

[0010] The upper end of the sound pressure vector nested vertical linear array is connected to the mechanical swivel through a cable, the mechanical swivel is connected to the main floating body through a cable, the lower end of the sound pressure vector nested vertical linear array is connected to the photoelectric slip ring through a multi-core load-bearing electrical connector, the photoelectric slip ring, the voltage stabilizing instrument cabin, the releaser, the secondary floating body and the heavy object are connected in series in sequence through cables, and a voltage stabilizing device is provided inside the voltage stabilizing instrument cabin; the mechanical swivel and the photoelectric slip ring are used for the rotational torque of the sparse combination array to reduce the rotation of the cable with the sparse combination array.

[0011] A measurement method based on an underwater target radiation noise measurement system comprises the following steps:

[0012] Step 1: deploy an underwater target radiation noise measurement system in the measurement waters, receive the radiation noise signal of the measured target, and transform the received radiation noise signal of the measured target into the frequency domain;

[0013] Step 2: For the sound pressure spiral biconical volume array, an improved nested array constant beamwidth beamforming method is used to perform constant beamwidth beamforming on the entire sound pressure spiral biconical volume array using a convex optimization algorithm to obtain an ultra-wideband two-dimensional robust constant beamwidth beam, and then obtain the beamforming result B of the mid- and high-frequency band broadband radiation noise of the target under test. TBCA (f);

[0014] Step 3: For the sound pressure vector nested vertical linear array, an improved nested array constant beamwidth beamforming method is used, combined with the vector signal sound pressure and vibration velocity joint processing method, and the sound pressure channel and vibration velocity channel of the sound pressure vector nested vertical linear array are respectively subjected to ultra-wideband constant beamwidth beamforming using a convex optimization algorithm to obtain a two-dimensional robust constant beamwidth, thereby obtaining the beamforming result B of the low-frequency broadband radiated noise of the measured target. ULA (f);

[0015] Step 4: After combining the beamforming results of the sound pressure spiral biconical volume array and the sound pressure vector nested vertical linear array into B(f), perform spectrum analysis on B(f) to obtain the power spectrum density Q(f). Based on Q(f), calculate the 1 / 3 octave band sound pressure spectrum source level L of the measured target. pso (i) and broadband sound source level L p , to achieve effective measurement of the full-band radiated noise of the target under test;

[0016]

[0017] Where K is the number of time domain signal snapshots; f s is the signal sampling frequency; |·| represents the modulus value; i is the 1 / 3 octave frequency band number, f i is the center frequency of the i-th 1 / 3 octave frequency band; D is the distance from the reference origin to the equivalent sound center of the target under test; I is the number of 1 / 3 octave frequency bands contained in the wide band.

[0018] Furthermore, the broadband radiation noise signal s(t) of the measured target in step 1 is represented in the frequency domain as S(f), and the incoming wave direction is The incident sound wave is incident on the sparse array, and the pitch angle θ represents the angle between the incident direction of the sound wave and the z-axis. represents the angle between the incident sound wave and the x-axis after being projected on the horizontal plane. The array receiving signal model X(f) is expressed as:

[0019]

[0020] in, is the steering vector of the sparse combination array, f is the frequency of the broadband radiation noise signal of the target under test, τ is the delay of the received signal of the array element in the sparse combination array relative to the reference origin, c represents the propagation speed of underwater sound waves, r is the spatial coordinate of the array element in the sparse combination array, u is the unit direction vector of the incident sound wave,

[0021] Furthermore, the step 2 is specifically as follows: establish a sound pressure spiral double cone volume array model composed of N1×M1 isotropic array elements, and the position coordinates of the (n1, m1)th array element in the three-dimensional space are for:

[0022]

[0023] Among them, n1=1,2,K,N1; m1=1,2,…,M1; are the x-axis, y-axis, and z-axis coordinates of the (n1, m1)th array element, respectively. is the elevation angle of the (n1,m1)th array element relative to the origin; is the azimuth angle of the (n1,m1)th array element relative to the origin; Represents the geometric distance between the (n,m)th array element and the reference origin, and the specific form is:

[0024]

[0025] The delay of the received signal of the (n1,m1)th array element relative to the reference origin It is expressed as:

[0026]

[0027] Steering vector of acoustic pressure spiral biconical volume array for:

[0028]

[0029] The frequency domain output of the array is X TBCA (f) is expressed as:

[0030]

[0031] Among them, N TBCA (f) is the additive noise matrix received by each element of the acoustic pressure spiral biconical volume array; for the broadband radiation noise signal received by the acoustic pressure spiral biconical volume array, it is divided into L TBCA The frequency sub-bands are analyzed, and the lth TBCA The beamforming result on the frequency sub-band is B TBCA,lTBCA (f) is expressed as:

[0032] B TBCA,lTBCA (f) = w TBCA (f lTBCA ) H X TBCA (f), f∈F lTBCA

[0033] Among them, w TBCA (f lTBCA ) indicates the first TBCA The weighted vector of the sound pressure spiral biconical volume array of the frequency subband; f lTBCA is the center frequency of the subband; the superscript H indicates conjugate transpose; F lTBCA For the first TBCA frequency sub-band range;

[0034] The convex optimization algorithm is used to solve the acoustic pressure of the spiral biconical volume array. TBCA The weight vector w of the frequency subbands TBCA (f lTBCA ), realize constant beamwidth beamforming, the expression is:

[0035]

[0036] Where Θ is the range of the pitch angle θ, which is [0,π]; Ψ is the azimuth angle The range of B is [0,2π]; d (Θ MI ,Ψ MJ ) is the amplitude of the desired beam main lobe; Θ MI is the elevation angle range corresponding to the desired beam main lobe, Θ SI is the elevation angle range corresponding to the desired beam sidelobe, Ψ MJ is the azimuth range corresponding to the desired beam main lobe, Ψ SJ is the azimuth range corresponding to the expected beam side lobe. The expected beam main lobe can be adjusted according to the actual target size and test distance; δ s is the upper bound constraint of the azimuth beam sidelobe, η s is the upper bound constraint of the elevation angle beam sidelobe, and ζ0 is the upper bound constraint of the second norm of the weighted vector.

[0037] Furthermore, the step 3 is specifically as follows: the number of vector array elements in the sound pressure vector nested vertical line array is N v , the number of sound pressure array elements is N p , sound pressure vector nested vertical array sound pressure channel guide vector A p (f,θ) and the velocity channel guide vector They are:

[0038]

[0039]

[0040] in, is the sound pressure array element guidance vector; is the sound pressure channel guiding vector of the vector array element; r0 is the distance from the reference origin to the sound center of the measured target; For number n p The sound pressure array element steering vector, is the distance from the sound pressure array element to the sound center of the target being measured, n p =1,2,KN p ; For number n v The sound pressure channel guide vector of the vector array element, is the distance from the vector array element to the acoustic center of the target being measured, n v =1,2,KN v ; is the incoming wave direction; the sound pressure channel frequency domain output X of all sound pressure array elements and vector array elements in the sound pressure vector nested vertical linear array ULA,p (f) is expressed as:

[0041] X ULA,p (f) = A p (f,θ)S(f)+N ULA,p (f)

[0042] Among them, N ULA,p (f) is the additive noise matrix received by all sound pressure channels in the sound pressure vector nested vertical linear array;

[0043] Frequency domain output of acoustic combination velocity of vector array elements in a vertical array with sound pressure vector nesting It is expressed as:

[0044]

[0045] Among them, N ULA,v (f) is the additive noise matrix received by all vector array elements in the sound pressure vector nested vertical linear array;

[0046] For the broadband radiated noise signal received by the vertical array with sound pressure vector nesting, it is divided into L ULA The frequency sub-bands are analyzed, and the lth ULA The result of beamforming on frequency subbands It is expressed as:

[0047]

[0048] in, Indicates the center frequency is The first ULA The sound pressure vector of each frequency sub-band is embedded in the vertical linear array sound pressure channel weighting vector; Indicates the center frequency is The first ULA The sound pressure vector of each frequency sub-band is nested with the vertical linear array velocity channel weighting vector; For the first ULA frequency sub-band range;

[0049] The convex optimization algorithm is used to solve the sound pressure vector of the nested vertical array. ULA The sound pressure channel weight vector of the frequency subband and the combined velocity channel weight vector To achieve constant beamwidth beamforming, the expression is:

[0050]

[0051]

[0052] Among them, B d,p (Θ MI ) is the main lobe amplitude of the desired beam at the pitch angle; ΘMI is the pitch angle range corresponding to the desired beam main lobe; Θ SI is the pitch angle range corresponding to the expected beam side lobe. The expected beam main lobe pitch angle range can be adjusted according to the actual vertical scale of the target to be measured and the test distance; is the main lobe amplitude of the desired beam in azimuth, Ψ MJ is the azimuth range corresponding to the desired beam main lobe, Ψ SJ is the azimuth angle range corresponding to the expected beam side lobe. The azimuth angle range of the expected beam main lobe can be adjusted according to the actual horizontal scale of the target to be measured and the test distance; δ s is the upper bound constraint of the azimuth beam sidelobe, η s is the upper bound constraint of the elevation angle beam sidelobe, and ζ0 is the upper bound constraint of the second norm of the weighted vector.

[0053] A computer device / equipment / system comprises a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above-mentioned underwater target radiated noise measurement method.

[0054] A computer-readable storage medium stores a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned underwater target radiation noise measurement method.

[0055] A computer program product comprises a computer program / instruction, which implements the steps of the above-mentioned underwater target radiated noise measurement method when executed by a processor.

[0056] The beneficial effects of the present invention are:

[0057] Aiming at the problem of measuring the radiated noise of underwater low-noise targets, the present invention designs a sparse combination array formed by a sound pressure spiral double-cone volume array and a sound pressure vector nested vertical linear array with a sparse structure. By adopting a frequency band testing scheme of a combination array of a high-frequency volume array and a low-frequency vertical linear array and a combined measurement method of a sound pressure hydrophone and a vector hydrophone, the measurement frequency band is extended to achieve effective measurement of the full-band radiated noise of underwater targets. By using a sparse array structure and an improved constant beamwidth beamforming method, a two-dimensional robust constant beamwidth beam is obtained while reducing the number of array elements and the array complexity, and a suitable main lobe width and a lower sidelobe level can be adjusted according to the measured target and the measurement distance. In the mid-high frequency band, for the sound pressure spiral double cone volume array, an improved nested array constant beamwidth beamforming method is used to achieve two-dimensional robust constant beamwidth beamforming; in the low frequency band, for the sound pressure vector nested vertical linear array, an improved nested array constant beamwidth beamforming method is used in combination with a vector signal sound pressure velocity joint processing method and a near-field focusing method to obtain unilateral directivity to improve array gain, effectively expand the lower limit frequency of measurement, and improve measurement accuracy. The present invention reduces the redundancy of measurement array elements, solves the problems of limited working bandwidth and two-dimensional robust constant beamwidth beamforming in noise measurement, and achieves accurate measurement of broadband radiated noise of underwater targets. In addition, the beam directivity of the measurement system can be adjusted through signal processing methods, making it more flexible and applicable to various application scenarios of underwater radiated noise measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the deployment of an underwater target radiated noise measurement system with a sparse combination array.

[0059] FIG2( a ) is a diagram showing the position of array elements of a sound pressure vector nested vertical linear array.

[0060] FIG2( b ) is a three-dimensional view of the array element positions of the acoustic pressure spiral biconical volume array.

[0061] FIG3(a) is a diagram showing the beamforming result of a 10 Hz to 1 kHz sound pressure vector nested vertical linear array with a constant beam width in the vertical direction.

[0062] FIG3( b ) is a diagram showing the beamforming result of the spiral double-cone volume array with constant beam width in the vertical direction at 1 kHz to 50 kHz sound pressure.

[0063] FIG3(c) is a diagram showing the beamforming result of a 10 Hz to 1 kHz sound pressure vector nested vertical linear array with a constant beam width in the horizontal direction.

[0064] FIG3( d ) is a diagram showing the beamforming result of the spiral double-cone volume array with constant beam width in the horizontal direction at a sound pressure range of 1 kHz to 50 kHz.

[0065] Figure 4 This is a graph showing the relationship between the sparse combination array gain and the measurement frequency band.

[0066] Figure 5 It is a summary table of the constant beamwidth beamforming performance of sparse combination array. DETAILED DESCRIPTION

[0067] The present invention is further described below in conjunction with the accompanying drawings.

[0068] Aiming at the problem of measuring broadband radiated noise of low-noise underwater targets, the present invention proposes a sparse combination array measurement system, method, program and storage medium for underwater target radiated noise measurement. The sparse combination array measurement system adopts a frequency band test scheme: in the medium and high frequency bands, the sound pressure spiral double cone volume array is used to solve the problem of array element redundancy and difficulty in high-frequency array formation through the sparse array element arrangement of the volume array single line array, and then the horizontal beam and the vertical beam are respectively subjected to broadband robust constant beam width beamforming in combination with the constant beam width beamforming method, so as to expand the upper limit frequency of measurement and realize the measurement of broadband radiated noise in the medium and high frequency bands; in the low frequency band, the sparse structure of the vertical line array and the combined array scheme of the sound pressure hydrophone and the vector hydrophone are used, and the constant beam width beamforming method and the vector signal sound pressure vibration velocity joint processing method are combined to obtain stable unilateral directivity, and a large measurement gain is obtained while the number of array elements is small and the array aperture is small, so as to expand the lower limit frequency of measurement and realize the measurement of broadband radiated noise in the low frequency band. The present invention aims to reduce the redundancy of measurement array elements, solve the problems of limited working bandwidth and two-dimensional robust constant beamwidth beamforming in noise measurement, and realize accurate measurement of full-band radiated noise of underwater targets.

[0069] Firstly, a sparse combination array of high-frequency sound pressure spiral double cone volume array and a low-frequency large aperture sound pressure vector nested vertical linear array are designed, and the supporting hardware system and data processing module are designed to form a radiated noise measurement system. The system includes a wet-end test platform and a dry-end data processing device. The wet-end platform includes a sparse combination test array, an underwater navigation positioning device, a depth sensor, an attitude sensor, an electronic instrument cabin, a sound pressure spiral double cone volume array titanium alloy frame structure, a pressure stabilizing instrument cabin, a signal transmission optoelectronic composite cable, a float-swivel-weight mooring system and a plastic-coated steel cable.

[0070] The schematic diagram of the sparse combination array measurement system is as follows: Figure 1As shown. The system includes a wet-end test platform and a dry-end data processing device. The wet-end platform includes a sparse combination test array, an underwater navigation and positioning device, a depth sensor, an attitude sensor, an electronic instrument cabin, a sound pressure spiral double-cone volume array titanium alloy array frame structure, a pressure-stabilizing instrument cabin, a signal transmission optoelectronic composite cable, a float-swivel-weight mooring system and a plastic-coated steel cable; the sparse combination test array includes a high-frequency sound pressure spiral double-cone volume array and a low-frequency large-aperture sound pressure vector nested vertical linear array (with depth sensors embedded at both ends of the array); the underwater navigation and positioning device includes a synchronous acoustic beacon and an underwater navigation and positioning base array; the electronic instrument cabin is equipped with a signal conditioning module and a data acquisition control module, and contains an attitude sensor; the sound pressure spiral double-cone volume array adopts a high-strength, lightweight, corrosion-resistant mesh frame structure, and the volume array frame structure is moored to the sound pressure vector nested by 8 plastic-coated steel cables on the upper and lower ends. The intermediate transfer mooring parts of the vertical linear array realize the combined installation of the sound pressure vector nested vertical linear array and the high-frequency sound pressure spiral double-cone volume array; the underwater navigation positioning array and the electronic instrument cabin are fixed on the array frame; the voltage stabilizing device is installed inside the voltage stabilizing instrument cabin; the signal transmission optoelectronic composite cable connects the wet end test platform and the dry end data processing device, which is used to supply power to the wet end test platform and transmit data and control commands; the float-swivel-weight mooring system includes a main float, a secondary float, a mechanical swivel, an intermediate transfer mooring part (containing a depth sensor and an attitude sensor), an optoelectronic slip ring, a releaser and an anchor block; the sparse combination test array is vertically suspended in the water through the float-swivel-weight mooring system to ensure its vertical attitude in the water, and the mechanical swivel at the upper end and the optoelectronic slip ring at the lower end of the sparse combination test array are used to release the rotational torque of the measurement array and reduce the rotation of the optical cable with the measurement array.

[0071] The core part of the sparse combination array measurement system is the sparse combination test array, which is composed of a sound pressure spiral double cone volume array with a sparse structure and a sound pressure vector nested vertical linear array. The sound pressure vector nested vertical linear array passes through the center of the sound pressure spiral double cone volume array, and its array center array element is located at the center of the circular cross section with the smallest radius of the sound pressure spiral double cone volume array and is perpendicular to the cross section, that is, the geometric centers of the two coincide; the upper end of the sound pressure spiral double cone volume array is connected to the mooring ring of the intermediate transition mooring component 1 through a plastic-coated steel cable, and the lower end is connected to the mooring ring of the intermediate transition mooring component 2 through a plastic-coated steel cable. The two mooring components transmit upward and downward pulling forces respectively to make the spiral double cone volume array vertically arranged and ensure that its central array element is in the same plane as the central array element of the sound pressure vector nested vertical linear array; the upper end of the sound pressure vector nested vertical linear array is connected to the mechanical swivel through the plastic-coated steel cable, and the lower end is connected to the photoelectric slip ring through a multi-core load-bearing electrical connector. The mechanical swivel and the photoelectric slip ring transmit upward and downward pulling forces respectively to make the sound pressure vector nested vertical linear array vertically arranged.

[0072] The sound pressure spiral double-cone volume array is used to measure the radiated noise of underwater targets in the mid- and high-frequency bands. M1 single sparse line arrays with the same number of array elements and N1 are evenly arranged on a circle with a radius of R to form a cylindrical array with a radius of R and a height of L. Then the bottom circle is fixed and the top circle is rotated counterclockwise around the cylindrical axis by an angle α, where the value of α is between 0° and 180°.

[0073] The single sparse linear array adopts a cross-octave sparse nested array, which consists of M2 array elements and N Tl The uniform sound pressure subarrays are concentrically nested, and the array element spacings in each uniform sound pressure subarray are d1,3d1,9d1,..., 2≤M2≤4.

[0074] For example, a single sparse linear array can be composed of three array elements with N Tl The uniform sound pressure subarrays are concentrically nested, and the array element spacings of subarray 1, subarray 2 and subarray 3 are d1, 3d1, and 9d1 respectively. The total length of the linear array is 9(N1-1)d1.

[0075] The sound pressure vector nested vertical linear array is used to measure the low-frequency radiation noise of underwater targets. The sound pressure vector nested vertical linear array adopts a 2-octave sparse nested array, which consists of M3 array elements and N L The uniform sub-arrays are concentrically nested, and the element spacings in each uniform sub-array are d2, 4d2, 16d2, ..., Some uniform subarrays are combined sound pressure vector arrays, and the number of vector array elements in the combined sound pressure vector array is M. v ;2≤M3≤4.

[0076] For example, the sound pressure vector nested vertical array can be composed of two array elements with N L The uniform sub-arrays are concentrically nested. The array element spacings of sub-array 1 and sub-array 2 are d2 and 4d2 respectively. Sub-array 1 (high-frequency sub-array) is a sound pressure vector combination array. The number of vector array elements is N v , the number of sound pressure array elements is N L -N v , subarray 2 is the sound pressure array, and the total length of the sound pressure vector nested vertical linear array is 4(N2-1)d2.

[0077] The sparse combination array measurement system is used to measure the radiation noise of the target under test, obtain the radiation noise signal of the target under test received by the sparse combination array, and transform the received radiation noise signal of the target under test into the frequency domain.

[0078] Assume that the broadband radiation noise signal of the measured target is s(t), and its frequency domain expression is S(f). The incident sound wave is incident on the sparse array, where the pitch angle θ represents the angle between the incident direction of the sound wave and the z-axis, and the azimuth angle It represents the angle between the incident sound wave and the x-axis after being projected on the horizontal plane. At this time, the unit direction vector u of the incident sound wave of the base array is:

[0079]

[0080] Then the time delay τ of the received signal of the base array element relative to the reference origin can be expressed as:

[0081]

[0082] In the formula, c represents the propagation speed of underwater sound waves. The sound speed c is a function of depth, but in general, to simplify the calculation, the sound speed can be approximately considered to be a constant value; r is the spatial coordinate of the base array element. After obtaining the time delay, the steering vector of the base array can be obtained. for:

[0083]

[0084] Where f is the frequency of the radiated noise signal to be measured. Let X(f) be the received signal of each array element, which generally includes the sound source signal and the noise signal after propagation through the channel. Then the array received signal model X(f) can be expressed as:

[0085]

[0086] Where N(f) is the receiving noise matrix of each array element.

[0087] Using the acoustic pressure spiral biconical volume array, combined with the sparse array scheme and the improved nested array constant beamwidth beamforming method, the convex optimization algorithm is used to solve the weighted vectors at different inherent frequencies of the volume array as a whole to obtain an ultra-wideband two-dimensional robust constant beamwidth beam, and then the mid- and high-frequency broadband radiation noise of the target obtained in step 1 is measured.

[0088] Establish a sound pressure spiral double cone volume array model composed of N1×M1 isotropic array elements to receive the radiation noise signal of the target under test. The position coordinates of the (n1,m1)th array element in three-dimensional space are for:

[0089]

[0090] In the formula, are the x-axis, y-axis, and z-axis coordinates of the (n1, m1)th array element, respectively. is the pitch angle of the (n1,m1)th array element relative to the origin, is the azimuth angle of the (n1,m1)th array element relative to the origin, Represents the geometric distance between the (n,m)th array element and the reference origin, and the specific form is:

[0091]

[0092] In the formula, there exists a relationship of n1=1,2,K,N1; m1=1,2,…,M1. Then the delay of the received signal of the (n1,m1)th array element relative to the reference origin is It can be expressed as:

[0093]

[0094] Then, the steering vector of the acoustic pressure spiral biconical volume array is for:

[0095]

[0096] The frequency domain output of the array is X TBCA (f) is expressed as:

[0097]

[0098] Where N TBCA (f) is the additive noise matrix received by each element of the acoustic pressure spiral biconical volume array. The broadband radiation noise signal received by the acoustic pressure spiral biconical volume array is divided into L TBCA The frequency sub-bands are analyzed, and the lth TBCA The result of beamforming on frequency subbands It can be simply expressed as:

[0099]

[0100] In the formula, Indicates the center frequency is The first TBCA The weighted vector of the sound pressure spiral biconical volume array of the frequency subband, H represents the conjugate transpose, For the first TBCA The convex optimization algorithm is used to solve the sound pressure of the spiral biconical volume array. TBCA The weight vector of the frequency subbands

[0101]

[0102] Where Θ is the range of the pitch angle θ, which is generally [0,π]; Ψ is the azimuth angle The range is usually [0,2π]; B d (Θ MI ,Ψ MJ ) is the amplitude of the desired beam main lobe; Θ MI is the elevation angle range corresponding to the desired beam main lobe, Θ SI is the elevation angle range corresponding to the desired beam sidelobe, Ψ MJis the azimuth range corresponding to the desired beam main lobe, Ψ SJ is the azimuth range corresponding to the expected beam side lobe. The expected beam main lobe can be adjusted according to the actual target size and test distance; δ s is the upper bound constraint of the azimuth beam sidelobe, η s is the upper bound constraint of the elevation angle beam sidelobe, and ζ0 is the upper bound constraint of the second norm of the weighted vector.

[0103] The measurement gain of the sound pressure spiral double-cone volume array is mainly divided into array gain and time processing gain, which can be expressed as:

[0104] G A,TBCA =AG TBCA +G T,TBCA

[0105] In the formula, AG TBCA represents the spatial gain of the sound pressure spiral biconical volume array, G T,TBCA Represents the time processing gain of the sound pressure spiral biconical volume array.

[0106] Assume that the signal field, noise field and directivity function of the sound pressure spiral double cone volume array are represented by functions and Indicates that, then from the spatial azimuth Within the unit spatial angle Ω incident on the base array, the power of the signal and noise can be expressed by the result of the mutual integration of the three functions. At this time, the array gain is:

[0107]

[0108] The time processing gain of the sound pressure spiral biconical volume array is the gain that can be obtained by integrating in the frequency domain and can be expressed as:

[0109] G T,TBCA =5lgBT

[0110] Where B is the bandwidth and T is the integration time length.

[0111] Using the sound pressure vector nested vertical linear array, based on the sparse structure and the combined array scheme of sound pressure hydrophones and vector hydrophones, an improved nested array constant beamwidth beamforming method is adopted to combine the vector signal sound pressure velocity joint processing method with the near-field focusing beamforming method to form an ultra-wideband two-dimensional robust constant beamwidth beam. The beamforming method is combined with the acoustic vector array test technology to obtain additional coherent signal processing gain, and the low-frequency wide-band radiated noise of the target obtained in step 1 is measured.

[0112] The vector hydrophone can synchronously pick up the three orthogonal components of the sound pressure signal p(t) and the particle velocity v(t) in the sound field at a point in space. x(t),v y (t),v z (t)}. In space, the far-field plane wave is The signal s(t) can be projected into a three-dimensional rectangular coordinate system according to the direction of the incoming wave. The sound pressure signal p(t) and the three-directional vibration velocity signal components can be written as:

[0113] p(t)=s(t),

[0114]

[0115]

[0116] v z (t) = s(t)cosθ

[0117] In the formula, {v x (t),v y (t),v z (t)} are the projections of s(t) on the three orthogonal directions of x, y, and z axes in three-dimensional space, that is, the acoustic signals received by the vector hydrophone velocity channel. If the three mutually orthogonal velocity signals are combined, the combined velocity v can be obtained. c (t):

[0118]

[0119] In the formula, represents the horizontal guidance azimuth angle, and θ0 represents the vertical guidance pitch angle.

[0120] Assume that the number of sound pressure vector nested vertical linear array vector elements is N v , the number of sound pressure array elements is N p , then the sound pressure vector is nested in the vertical array sound pressure channel guide vector A p (f,θ) and the velocity channel guide vector They are:

[0121]

[0122] In the formula, is the sound pressure array element guidance vector; is the sound pressure channel guiding vector of the vector array element; r0 is the distance from the reference origin to the sound center of the measured target; For number n p The sound pressure array element steering vector, is the distance from the sound pressure array element to the sound center of the target being measured, n p =1,2,KN p ; For number n v The sound pressure channel guide vector of the vector array element, is the distance from the vector array element to the acoustic center of the target being measured, n v =1,2,KN v ; is the steering vector of a single vector hydrophone; The frequency domain output of all sound pressure channels (including sound pressure array elements and vector array element sound pressure channels) in the sound pressure vector nested vertical linear array is X ULA,p (f) is expressed as:

[0123] X ULA,p (f) = A p (f,θ)S(f)+N ULA,p (f)

[0124] Where N ULA,p (f) is the additive noise matrix received by all sound pressure channels in the sound pressure vector nested vertical linear array. The frequency domain output of the vector array element acoustic combination velocity in the sound pressure vector nested vertical linear array It is expressed as:

[0125]

[0126] Where N ULA,v (f) is the additive noise matrix received by all vector array elements in the sound pressure vector nested vertical linear array.

[0127] The sound pressure channel and the combined vibration velocity are combined into "(p+v c ) 2 "The combined processing of the form of " divides the broadband radiated noise signal received by the sound pressure vector nested vertical linear array into L ULA The frequency sub-bands are analyzed, and the lth ULA The result of beamforming on frequency subbands It can be simply expressed as:

[0128]

[0129] In the formula, Indicates the center frequency is The first ULA The sound pressure vector of the frequency sub-band is embedded in the vertical array sound pressure channel weighting vector, Indicates the center frequency is The first ULA The sound pressure vector of the frequency sub-band is embedded in the vertical linear array vibration channel weight vector, H represents the conjugate transpose, For the first ULA The convex optimization algorithm is used to solve the sound pressure vector of the nested vertical linear array. ULA The sound pressure channel weight vector of the frequency subband and the combined velocity channel weight vector To achieve constant beamwidth beamforming, the expressions are:

[0130]

[0131] In the formula, B d,p (Θ MI ) is the amplitude of the main lobe of the desired beam at the pitch angle, and the main lobe of the desired beam can be adjusted according to the actual size of the target to be measured and the test distance; Θ MI is the elevation angle range corresponding to the main lobe of the beam; Θ SI The pitch angle range corresponding to the beam side lobe is determined according to the size of the target and the test distance; is the main lobe amplitude of the desired beam in azimuth, Ψ MJ is the azimuth range corresponding to the main lobe of the beam, Ψ SJ is the azimuth angle range corresponding to the beam sidelobe; δ s is the upper bound constraint of the azimuth beam sidelobe, η s is the upper bound constraint of the elevation angle beam sidelobe, and ζ0 is the upper bound constraint of the second norm of the weighted vector.

[0132] The sound pressure vector nested vertical linear array measurement gain can be expressed as:

[0133] G A,ULA =AG ULA +G T,ULA

[0134] In the formula, AG ULA represents the spatial gain of the sound pressure vector nested vertical array, G T,ULA The spatial gain AG of the sound pressure vector nested vertical line array. ULA Calculation method and spatial gain AG of acoustic pressure spiral biconical volume array TBCA The calculation method is the same. The time processing gain G of the sound pressure vector nested vertical linear array T,ULA The expression is as follows:

[0135] G T,ULA =5lgBT+k

[0136] In the formula, k is the joint processing gain of sound pressure and vibration velocity, and its expression is:

[0137]

[0138] In the formula, and are the acoustic pressure velocity coherence coefficients of the signal field and the noise field at frequency f0. The noise is completely isotropic When , the joint processing gain tends to infinity. The actual ocean environmental noise is not completely isotropic. When the coherence coefficient of the noise field When the values ​​are 0.5, 0.25 and 0.1 respectively, the joint processing gain k is 6dB, 12dB and 20dB.

[0139] After obtaining the beamforming results of the sparse combination array, a spectrum analysis is performed on it to calculate and obtain parameter information such as the 1 / 3 octave band sound pressure spectrum source level and broadband sound source level of the target under test, so as to achieve effective measurement of the full-band radiation noise of the target under test; among them, the radiation noise in the medium and high frequency bands is measured by the sound pressure spiral double-cone volume array noise measurement, and the radiation noise in the low frequency band is measured by the sound pressure vector nested vertical linear array.

[0140] The beamforming result B(f) of the sparse combination array can be expressed as:

[0141]

[0142] Perform power spectrum analysis on it and obtain the power spectrum density Q(f):

[0143]

[0144] Where K is the number of time domain signal snapshots, f s is the signal sampling frequency, and |·| represents the modulus value.

[0145] Calculate the 1 / 3 octave band sound pressure spectrum source level L based on the power spectrum density pso (i)

[0146]

[0147] Where i is the 1 / 3 octave frequency band number, f i is the center frequency of the i-th 1 / 3 octave frequency band, and D is the distance from the reference origin to the equivalent sound center of the target being measured.

[0148] Broadband sound source level L p The calculation formula is as follows:

[0149]

[0150] Where I is the number of 1 / 3 octave bands contained in the wideband.

[0151] The actual effect of the present invention is analyzed below in conjunction with a simulation example.

[0152] Simulation 1: Design sparse combination array to cover the frequency range [10Hz, 50kHz]. Design the sound pressure vector nested vertical array to work in the range [10Hz, 1kHz]. Combined with the improved nested array constant beamwidth beamforming method, the working frequency band of a single subarray is set to 2 octaves. Considering the limitations of array potting, transportation, engineering deployment, etc., the sound pressure vector nested vertical array consists of 2 array elements with N L =17 uniform sub-arrays are concentrically nested, the array element spacings of sub-array 1 and sub-array 2 are d2=1m and 4d2=4m respectively, sub-array 1 is a sound pressure vector combination array, and the number of vector array elements is N v =9, the number of sound pressure array elements is 8, subarray 2 is the sound pressure array, the total length of the sound pressure vector nested vertical linear array is 64m, the total number of array elements is 29, and the position diagram of the sound pressure vector nested vertical linear array elements is shown in Figure 2(a), where the red array elements are vector array elements and the black array elements are sound pressure array elements. The sound pressure spiral biconical volume array is designed, and the operating frequency range is [1kHz, 50kHz]. Combined with the improved nested array constant beamwidth beamforming method, the single sparse linear array of the sound pressure spiral biconical volume array adopts a cross-octave sparse nested array. The number of single sparse linear array elements is N1=29, which consists of 3 array elements N. Tl =13 uniform sound pressure subarrays are concentrically nested, and the array element spacings of subarray 1, subarray 2 and subarray 3 are d1=0.04m, 3d1=0.12m, 9d1=0.36m respectively. The total length of the linear array is 4.32m. The sound pressure spiral double cone volume array is formed by twisting M1=12 single sparse linear arrays of sound pressure spiral double cone volume arrays by 160°. The maximum radius is R=0.72m, the overall height is 4.08m, and the total number of array elements is 348. The three-dimensional view of the array element position of the sound pressure spiral double cone volume array is shown in Figure 2(b).

[0153] Simulation 2: The simulation frequency range is [10Hz, 50kHz], and the incoming wave direction is For the sound pressure vector nested vertical linear array, the simulation frequency range is [10Hz, 1kHz]. The improved nested array constant beamwidth beamforming method is combined with the vector signal sound pressure velocity joint processing method and the near-field focusing method to form a two-dimensional robust constant beamwidth. The results are shown in Figure 3(a) and Figure 3(c). For the sound pressure spiral double cone volume array, the simulation frequency range is [1kHz, 50kHz]. The improved nested array constant beamwidth beamforming method is used to perform convex optimization constraints on the entire volume array to achieve constant beamwidth beamforming in the vertical and horizontal directions of the volume array. The results are shown in Figure 3(b) and Figure 3(d). The array gain of the sparse combination array with a frequency range of [10Hz, 50kHz] is calculated as follows Figure 4 The beamforming performance of sparse combination array with constant beam width is shown in Figure 5As shown in the figure, the simulation results show that the sparse combination array measurement has a relatively stable beam width in the [50Hz, 25kHz] frequency band and a high array gain in the [10Hz, 1kHz] frequency band, which can achieve effective measurement of underwater low-noise targets.

[0154] Aiming at the problem of measuring the radiated noise of underwater low-noise targets, the present invention designs a sparse combination array formed by a sound pressure spiral double-cone volume array and a sound pressure vector nested vertical linear array with a sparse structure. By adopting a frequency band testing scheme of a combination array of a high-frequency volume array and a low-frequency vertical linear array and a combined measurement method of a sound pressure hydrophone and a vector hydrophone, the measurement frequency band is extended to achieve effective measurement of the full-band radiated noise of underwater targets. By using a sparse array structure and an improved constant beamwidth beamforming method, a two-dimensional robust constant beamwidth beam is obtained while reducing the number of array elements and the array complexity, and a suitable main lobe width and a lower sidelobe level can be adjusted according to the measured target and the measurement distance. In the mid-high frequency band, for the sound pressure spiral double cone volume array, an improved nested array constant beamwidth beamforming method is used to achieve two-dimensional robust constant beamwidth beamforming; in the low frequency band, for the sound pressure vector nested vertical linear array, an improved nested array constant beamwidth beamforming method is used in combination with a vector signal sound pressure velocity joint processing method and a near-field focusing method to obtain unilateral directivity to improve array gain, effectively expand the lower limit frequency of measurement, and improve measurement accuracy. The present invention reduces the redundancy of measurement array elements, solves the problems of limited working bandwidth and two-dimensional robust constant beamwidth beamforming in noise measurement, and achieves accurate measurement of broadband radiated noise of underwater targets. In addition, the beam directivity of the measurement system can be adjusted through signal processing methods, making it more flexible and applicable to various application scenarios of underwater radiated noise measurement.

[0155] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sparse combination array, characterized in that: It includes a sound pressure spiral double cone volume array and a sound pressure vector nested vertical linear array; the sound pressure spiral double cone volume array is a cylindrical array with a fixed bottom circular ring, and the top circle is obtained by rotating a certain angle around the cylindrical axis; the cylindrical array includes multiple groups of single sparse linear arrays with the same number of array elements evenly arranged on the circumference; the single sparse linear array adopts a cross-octave sparse nested array, and the sound pressure vector nested vertical linear array adopts a 2-octave sparse nested array, the sound pressure vector nested vertical linear array passes through the center of the sound pressure spiral double cone volume array, the central array element of the sound pressure vector nested vertical linear array is located at the center of the circular cross-section with the smallest radius of the sound pressure spiral double cone volume array, and the central array element of the sound pressure spiral double cone volume array is in the same plane as the central array element of the sound pressure vector nested vertical linear array.

2. A sparse combination array according to claim 1, characterized in that: The sound pressure spiral double cone volume array includes M1 single sparse line arrays with N1 array elements; the single sparse line array consists of M2 array elements with N Tl The uniform sound pressure subarrays are concentrically nested, and the array element spacing in each uniform sound pressure subarray is d1,3d1,9d1,...,3 M2-1 d1;2≤M2≤4; The sound pressure vector nested vertical linear array consists of M3 array elements with N L The uniform sub-arrays are concentrically nested, and the element spacings in each uniform sub-array are d2,4d2,16d2,...,4 M3-1 d2, where some uniform subarrays are combined sound pressure vector arrays, and the number of vector array elements in the combined sound pressure vector array is M v ;2≤M3≤4.

3. An underwater target radiated noise measurement system with the sparse combination array according to claim 2, characterized in that: It includes a wet-end test platform and a dry-end data processing device, which are connected by a signal transmission optoelectronic composite cable; the wet-end test platform includes a sparse combination array, an underwater navigation and positioning array, a depth sensor, an electronic instrument cabin, a pressure-stabilizing instrument cabin, and a floating body-swivel-weight mooring system; the floating body-swivel-weight mooring system includes a main floating body, a secondary floating body, a mechanical swivel, an optoelectronic slip ring, a releaser, and an anchor block; The acoustic pressure spiral double cone volume array is installed in the array frame, the upper end of the array frame is connected to the first intermediate transition mooring piece through a cable, and the lower end of the array frame is connected to the second intermediate transition mooring piece through a cable; the underwater navigation positioning base array is installed on the top of the array frame, and the electronic instrument cabin is installed at the bottom of the array frame, and a posture sensor, a signal conditioning module and a data acquisition control module are arranged inside the electronic instrument cabin; the first intermediate transition mooring piece is connected to the upper end of the acoustic pressure spiral double cone volume array, and the second intermediate transition mooring piece is connected to the lower end of the acoustic pressure spiral double cone volume array, and a depth sensor and a posture sensor are arranged inside the first intermediate transition mooring piece and the second intermediate transition mooring piece, and the first intermediate transition mooring piece and the second intermediate transition mooring piece transmit upward and downward pulling forces respectively, so that the acoustic pressure spiral double cone volume array is arranged vertically and ensures that its central array element and the central array element of the acoustic pressure vector nested vertical linear array are in the same plane; The upper end of the sound pressure vector nested vertical linear array is connected to the mechanical swivel through a cable, the mechanical swivel is connected to the main floating body through a cable, the lower end of the sound pressure vector nested vertical linear array is connected to the photoelectric slip ring through a multi-core load-bearing electrical connector, the photoelectric slip ring, the voltage stabilizing instrument cabin, the releaser, the secondary floating body and the heavy object are connected in series in sequence through cables, and a voltage stabilizing device is provided inside the voltage stabilizing instrument cabin; the mechanical swivel and the photoelectric slip ring are used for the rotational torque of the sparse combination array to reduce the rotation of the cable with the sparse combination array.

4. A measurement method based on the underwater target radiation noise measurement system according to claim 3, characterized in that: The following steps are involved: Step 1: deploy an underwater target radiation noise measurement system in the measurement waters, receive the radiation noise signal of the measured target, and transform the received radiation noise signal of the measured target into the frequency domain; Step 2: For the sound pressure spiral biconical volume array, an improved nested array constant beamwidth beamforming method is used to perform constant beamwidth beamforming on the entire sound pressure spiral biconical volume array using a convex optimization algorithm to obtain an ultra-wideband two-dimensional robust constant beamwidth beam, and then obtain the beamforming result B of the mid- and high-frequency band broadband radiation noise of the target under test. TBCA (f); Step 3: For the sound pressure vector nested vertical linear array, an improved nested array constant beamwidth beamforming method is used, combined with the vector signal sound pressure and vibration velocity joint processing method, and the sound pressure channel and vibration velocity channel of the sound pressure vector nested vertical linear array are respectively subjected to ultra-wideband constant beamwidth beamforming using a convex optimization algorithm to obtain a two-dimensional robust constant beamwidth, thereby obtaining the beamforming result B of the low-frequency broadband radiated noise of the measured target. ULA (f); Step 4: After combining the beamforming results of the sound pressure spiral biconical volume array and the sound pressure vector nested vertical linear array into B(f), perform spectrum analysis on B(f) to obtain the power spectrum density Q(f). Based on Q(f), calculate the 1 / 3 octave band sound pressure spectrum source level L of the measured target. pso (i) and broadband sound source level L p , to achieve effective measurement of the full-band radiated noise of the target under test; Where K is the number of time domain signal snapshots; f s is the signal sampling frequency; |·| represents the modulus value; i is the 1 / 3 octave frequency band number, f i is the center frequency of the i-th 1 / 3 octave frequency band; D is the distance from the reference origin to the equivalent sound center of the target under test; I is the number of 1 / 3 octave frequency bands contained in the wide band.

5. The method for measuring underwater target radiated noise according to claim 4, characterized in that: The broadband radiation noise signal s(t) of the measured target in step 1 is represented by S(f) in the frequency domain. The incident sound wave is incident on the sparse array, and the pitch angle θ represents the angle between the incident direction of the sound wave and the z-axis. represents the angle between the incident sound wave and the x-axis after being projected on the horizontal plane. The array receiving signal model X(f) is expressed as: in, is the steering vector of the sparse combination array, f is the frequency of the broadband radiation noise signal of the target under test, τ is the delay of the received signal of the array element in the sparse combination array relative to the reference origin, c represents the propagation speed of underwater sound waves, r is the spatial coordinate of the array element in the sparse combination array, u is the unit direction vector of the incident sound wave, 6. The method for measuring underwater target radiated noise according to claim 5, characterized in that: The step 2 is specifically as follows: establish a sound pressure spiral double cone volume array model composed of N1×M1 isotropic array elements, and the position coordinates of the (n1, m1)th array element in the three-dimensional space are for: Among them, n1=1,2,K,N1; m1=1,2,…,M1; are the x-axis, y-axis, and z-axis coordinates of the (n1, m1)th array element, respectively. is the elevation angle of the (n1,m1)th array element relative to the origin; is the azimuth angle of the (n1,m1)th array element relative to the origin; Represents the geometric distance between the (n,m)th array element and the reference origin, and the specific form is: The delay of the received signal of the (n1,m1)th array element relative to the reference origin It is expressed as: Steering vector of acoustic pressure spiral biconical volume array for: The frequency domain output of the array is X TBCA (f) is expressed as: Among them, N TBCA (f) is the additive noise matrix received by each element of the acoustic pressure spiral biconical volume array; for the broadband radiation noise signal received by the acoustic pressure spiral biconical volume array, it is divided into L TBCA The frequency sub-bands are analyzed, and the lth TBCA The result of beamforming on frequency subbands It is expressed as: in, Indicates the first TBCA The weighted vector of the sound pressure spiral biconical volume array of the frequency subband; is the center frequency of the subband; the superscript H represents the conjugate transpose; For the first TBCA frequency sub-band range; The convex optimization algorithm is used to solve the acoustic pressure of the spiral biconical volume array. TBCA The weight vector of frequency subbands To achieve constant beamwidth beamforming, the expression is: Where Θ is the range of the pitch angle θ, which is [0,π]; Ψ is the azimuth angle The range of B is [0,2π]; d (Θ MI ,Ψ MJ ) is the expected beam main lobe amplitude; Θ MI is the elevation angle range corresponding to the desired beam main lobe, Θ SI is the elevation angle range corresponding to the desired beam sidelobe, Ψ MJ is the azimuth range corresponding to the desired beam main lobe, Ψ SJ is the azimuth range corresponding to the expected beam side lobe. The expected beam main lobe can be adjusted according to the actual target size and test distance; δ s is the upper bound constraint of the azimuth beam sidelobe, η s is the upper bound constraint of the elevation angle beam sidelobe, and ζ0 is the upper bound constraint of the second norm of the weighted vector.

7. The method for measuring underwater target radiated noise according to claim 6, characterized in that: The step 3 is specifically as follows: the number of vector array elements in the sound pressure vector nested vertical linear array is N v , the number of sound pressure array elements is N p , sound pressure vector nested vertical array sound pressure channel guide vector A p (f,θ) and the velocity channel guide vector They are: in, is the sound pressure array element guidance vector; is the sound pressure channel guiding vector of the vector array element; r0 is the distance from the reference origin to the sound center of the measured target; For number n p The sound pressure array element steering vector, is the distance from the sound pressure array element to the sound center of the target being measured, n p =1,2,KN p ; For number n v The sound pressure channel guide vector of the vector array element, is the distance from the vector array element to the acoustic center of the target being measured, n v =1,2,KN v ; is the incoming wave direction; the sound pressure channel frequency domain output X of all sound pressure array elements and vector array elements in the sound pressure vector nested vertical linear array ULA,p (f) is expressed as: X ULA,p (f)=A p (f,θ)S(f)+N ULA,p (f) Among them, N ULA,p (f) is the additive noise matrix received by all sound pressure channels in the sound pressure vector nested vertical linear array; Frequency domain output of acoustic combination velocity of vector array elements in a vertical array with sound pressure vector nesting It is expressed as: Among them, N ULA,v (f) is the additive noise matrix received by all vector array elements in the sound pressure vector nested vertical linear array; For the broadband radiated noise signal received by the vertical array with sound pressure vector nesting, it is divided into L ULA The frequency sub-bands are analyzed, and the lth ULA The result of beamforming on frequency subbands It is expressed as: in, Indicates the center frequency is The first ULA The sound pressure vector of each frequency sub-band is embedded in the vertical linear array sound pressure channel weighting vector; Indicates the center frequency is The first ULA The sound pressure vector of each frequency sub-band is nested with the vertical linear array velocity channel weighting vector; For the first ULA frequency sub-band range; The convex optimization algorithm is used to solve the sound pressure vector of the nested vertical array. ULA The sound pressure channel weight vector of the frequency subband and the combined velocity channel weight vector To achieve constant beamwidth beamforming, the expression is: Among them, B d,p (Θ MI ) is the main lobe amplitude of the desired beam at the pitch angle; Θ MI is the pitch angle range corresponding to the desired beam main lobe; Θ SI is the pitch angle range corresponding to the expected beam side lobe. The expected beam main lobe pitch angle range can be adjusted according to the actual vertical scale of the target to be measured and the test distance; is the main lobe amplitude of the desired beam in azimuth, Ψ MJ is the azimuth range corresponding to the desired beam main lobe, Ψ SJ is the azimuth angle range corresponding to the expected beam side lobe. The azimuth angle range of the expected beam main lobe can be adjusted according to the actual horizontal scale of the target to be measured and the test distance; δ s is the upper bound constraint of the azimuth beam sidelobe, η s is the upper bound constraint of the elevation angle beam sidelobe, and ζ0 is the upper bound constraint of the second norm of the weighted vector.

8. A computer device / equipment / system comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 4 to 7.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 4 to 7 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 4 to 7 are implemented.

Images