A dual-line array focused beamforming passive positioning method based on deconvolution

Abstract

The present application discloses a dual-line array focused beamforming passive positioning method based on deconvolution, which relates to the technical field of passive positioning. The method utilizes a receiving array of a dual-line array structure in combination with focused beamforming to obtain a sound source distribution map. Compared with the conventional method of using a single-line array structure, the left and right distinguishing capability can be improved, and the positioning accuracy can be improved. The obtained sound source distribution map is not directly used for positioning, but is deconvolved with a near-field directivity function calculated according to the formation parameters of the receiving array to finally obtain a sound source positioning result, which further improves the positioning accuracy and precision, has higher resolution, lower side lobes, and better weak target resolution capability.

Description

Technical Field

[0001] The present application relates to the technical field of passive positioning, and in particular to a dual-line array focused beamforming passive positioning method based on deconvolution. Background Art

[0002] Vibration reduction and noise reduction have always been a hot topic in the field of underwater acoustics. Common noise source measurement methods include time domain analysis (i.e., using the characteristics of the autocorrelation function to separate the periodic components hidden in the noise), frequency domain analysis, time-frequency analysis, wavelet analysis, sound intensity measurement, acoustic holography, and beamforming. Various noise identification methods are applicable to different distances and frequencies, and each has its own advantages and disadvantages.

[0003] Focused beamforming technology is a typical technology for noise identification using the beamforming method. Focused beamforming technology is a high-precision passive positioning algorithm mainly for near-field targets. The focused beamforming algorithm can be used to perform spherical wave compensation on the received signal of a single-line array at different directions and distances in the measurement area, thereby providing a sound source distribution map of the target distribution and achieving passive positioning. However, the positioning accuracy of this approach is relatively low. Summary of the invention

[0004] In view of the above problems and technical requirements, the applicant proposes a dual-line array focused beamforming passive positioning method based on deconvolution. The technical solution of this application is as follows:

[0005] A dual-line array focused beamforming passive positioning method based on deconvolution, the method comprising:

[0006] The near-field directivity function of the receiving array is calculated according to the array parameters of the receiving array, and the near-field directivity function indicates the response of the receiving array to the sound waves at different spatial positions. The receiving array is a dual-line array structure, including two single-line arrays arranged in parallel and spaced apart.

[0007] The received signals acquired by the receiving array are combined with focused beam forming to obtain a sound source distribution map, where the sound source distribution map indicates the sound wave output at different spatial positions;

[0008] The sound source distribution diagram and the near-field directivity function of the receiving array are deconvolved to obtain the sound source localization result.

[0009] A further technical solution is to calculate the near-field directivity function of the receiving array to correspond to the spatial position of the sound source. The near-field directivity function corresponding to the sound source at different spatial positions has a different function shape, and the near-field directivity function of the receiving array is a shift function.

[0010] A further technical solution is that a method for performing a deconvolution operation on a sound source distribution diagram and a near-field directivity function of a receiving array comprises:

[0011] The two-dimensional extended RL algorithm is used to perform deconvolution operation on the near-field directivity function of the sound source distribution pattern receiving array.

[0012] A further technical solution is that the method for obtaining the sound source localization result by using the two-dimensional extended RL algorithm includes:

[0013] according to Iterate the solution until the iteration termination condition is reached, and then the sound source localization result q obtained by the r+1th iteration is (r+1) (x,y) is the sound source localization result;

[0014] Among them, q (r) (x,y) is the sound source localization result obtained by the rth iteration. represents the normalized acoustic wave output at any point (ξ,η) on the acoustic image scanning plane where the sound source and scanning point are located and B(ξ,η) is the sound wave output at (ξ,η) on the sound image scanning plane in the sound source distribution diagram, p(ξ,η|x,y) is the near-field directivity function at (ξ,η) on the acoustic image scanning plane, is the normalized near-field directivity function at (ξ,η) on the acoustic image scanning plane and

[0015] A further technical solution is that when a predetermined number of iterations is reached, or the sound source localization result q obtained by the r+1th iteration is (r+1) (x, y) and the sound source localization result q obtained by the rth iteration (r) When the error between (x, y) is less than the error threshold, it is determined that the iteration termination condition is met.

[0016] A further technical solution is that, when calculating the near-field directivity function of the receiving array, the array parameters of the receiving array used include the number of array elements in the receiving array and the spatial position coordinates of each array element.

[0017] A further technical solution is to calculate the receiving array and any spatial position (x 0 ,y 0 ,z 0 ) at the sound source s 0 (t) The corresponding near-field directivity function method includes:

[0018] According to the spatial position of each array element in the receiving array, the sound source s received by each array element of the receiving array is respectively 0The signal of (t) is subjected to spherical wave phase compensation according to the spatial position of the scanning point to obtain the compensation output at the scanning point, and the compensation output of each array element at the scanning point is weightedly summed to obtain the response of the receiving array to the sound wave at the scanning point; the focusing effect of the receiving array on the sound source at the scanning points at different spatial positions on the acoustic image scanning plane is obtained respectively, and the near-field directivity function is obtained, and the sound source and the scanning point are located in the same acoustic image scanning plane.

[0019] A further technical solution is that the response of the near-field directivity function of the receiving array to the sound wave at any scanning point is:

[0020]

[0021] The first single-line array in the receiving array includes N1 array elements arranged at intervals, and the second single-line array includes N2 array elements arranged at intervals. n1 is the sound source s received by the n1th array element in the first single-line array 0 (t) signal amplitude, A n2 is the sound source s received by the n2th array element in the second single-line array 0 (t) signal amplitude, d n1 is the spatial position (x 0 ,y 0 ,z 0 ) at the sound source s 0 (t) The distance to the n1th array element in the first single-line array, d n2 is the spatial position (x 0 ,y 0 ,z 0 ) at the sound source s 0 (t) The distance to the n2th array element in the second single-line array, d′ n1 is the distance between the scanning point and the n1th array element in the first single-line array, d′ n2 is the distance from the scanning point to the n2th array element in the second single-line array, and c represents the speed of sound.

[0022] A further technical solution is that the method for obtaining the sound source distribution map includes:

[0023] According to the spatial position of each array element in the receiving array, the receiving signals of each array element of the receiving array are respectively subjected to spherical wave phase compensation according to the spatial position of the scanning point to obtain the compensation output at the scanning point, and the compensation output of each array element at the scanning point is weighted summed to obtain the sound wave output at the scanning point, and the sound wave output at each scanning point on the acoustic image scanning plane is respectively obtained to obtain a sound source distribution map, and the sound source and the scanning point are located on the same acoustic image scanning plane.

[0024] A further technical solution is that the sound wave output at any scanning point in the sound source distribution diagram is obtained as follows:

[0025]

[0026] The first single-line array in the receiving array includes N1 array elements arranged at intervals, and the second single-line array includes N2 array elements arranged at intervals. n1,i is the i-th sound source s received by the n1-th array element in the first single-line array i (t) signal amplitude, A n2,i is the i-th sound source s received by the n2-th array element in the second single-line array i (t), i∈[1,I], where I is the number of sound sources involved, each of which is located at a different spatial position and has a different sound source signal; d n1 is the spatial position (x i ,y i ,z i ,) at the sound source s i (t) The distance to the n1th array element in the first single-line array, d n2 is the spatial position (x i ,y i ,z i ,) at the sound source s i (t) The distance to the n2th array element in the second single-line array, d′ n1 is the distance between the scanning point and the n1th array element in the first single-line array, d′ n2 is the distance from the scanning point to the n2th array element in the second single-line array, and c represents the speed of sound.

[0027] The beneficial technical effects of this application are:

[0028] The present application discloses a dual-line array focused beamforming passive positioning method based on deconvolution. The method utilizes a receiving array of a dual-line array structure in combination with focused beamforming to obtain a sound source distribution map. Compared with the conventional method of using a single-line array structure, the left and right discrimination capabilities can be improved, and the positioning accuracy can be improved. The obtained sound source distribution map is not directly used for positioning, but is deconvolved with the near-field directivity function of the receiving array to obtain a sound source positioning result, which further improves the positioning accuracy and precision, has higher resolution, lower side lobes, and better weak target resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a method flow chart of a passive positioning method in an embodiment.

[0030] Figure 2 The diagram is a schematic diagram of an application scenario of a passive positioning method in an embodiment.

[0031] Figure 3 It is a schematic diagram of the response of the sound wave at each scanning point corresponding to the near-field directivity function of the sound source with a spatial position of (10, -10, h) in a simulation example.

[0032] Figure 4 It is a schematic diagram of the response of the sound wave at each scanning point corresponding to the near-field directivity function of the sound source with a spatial position of (10,0,h) in a simulation example.

[0033] Figure 5 It is a schematic diagram of the response of the sound wave at each scanning point corresponding to the near-field directivity function of the sound source with a spatial position of (10, 10, h) in a simulation example.

[0034] Figure 6 It is a schematic diagram of the sound source distribution diagram obtained by using a single line array in a simulation example.

[0035] Figure 7 yes Figure 6 A schematic diagram of the sound source distribution diagram obtained using a dual-line array in the simulation example shown.

[0036] Figure 8 Yes Figure 7 The sound source distribution diagram shown is a sound source localization result obtained by performing a deconvolution operation on the passive localization method of the present application and the near-field directivity function. DETAILED DESCRIPTION

[0037] The specific implementation of the present application is further described below in conjunction with the accompanying drawings.

[0038] This application discloses a dual-line array focused beamforming passive positioning method based on deconvolution, please refer to Figure 1 The method flow chart shown in the figure comprises the following steps:

[0039] Step 120: Calculate the near-field directivity function of the receiving array according to the array parameters of the receiving array.

[0040] Please refer to Figure 2 As shown in the application scenario diagram of the method, the receiving array in the present application is a dual-line array structure, including two single-line arrays, which are respectively denoted as the first single-line array and the second single-line array. The first single-line array includes N1 array elements 1 that are arranged in sequence and at intervals to form a linear array structure, and the second single-line array includes N2 array elements 2 that are arranged in sequence and at intervals to form a linear array structure. The first single-line array and the second single-line array are located on the same horizontal plane XY and are parallel and spaced to form a receiving array of the dual-line array structure of the present application. The receiving array is arranged under the sea, generally on the seabed, and the vertical distance between the plane where the receiving array is located and the sea surface is H. The array depth of the receiving array can be denoted as H. In the present application, if Figure 2As shown, the plane where the sea surface is located is the OXY plane, and the direction perpendicular to the sea surface to the seabed is the Z direction, thereby forming a virtual coordinate system OXYZ. The acoustic image scanning plane of the receiving array and the sound source 3 are located on the same horizontal plane XY. The vertical distance between the acoustic image scanning plane and the sea surface is h, so the scanning depth of the receiving array is h. The acoustic image scanning plane is generally divided into a scanning grid, which includes a number of scanning points 4 at different positions.

[0041] The near-field directivity function of the receiving array indicates the response of multiple array elements to sound waves at different spatial positions. The near-field directivity function of the receiving array reflects the ability of the sound source to be located at different positions through the receiving array to gather the sound energy to the position. The receiving array in the present application is a near-field array. The directivity of the near-field array is not like a far-field linear array or a far-field rectangular array. There is a fixed calculation formula that can directly express the directivity function of the array in a concise manner. Therefore, in one embodiment, the following method for calculating the near-field directivity function is provided. When calculating the near-field directivity function of the receiving array, the array parameters of the receiving array used include the number of array elements in the receiving array and the spatial position coordinates of each array element.

[0042] Assumptions Figure 2 The sound source signal is s 0 The sound source 3 of (t) is located at the spatial position (x 0 ,y 0 ,z 0 ), then calculate the receiving array and the spatial position (x 0 ,y 0 ,z 0 ) at the sound source s 0 (t) The corresponding near-field directivity function method includes:

[0043] According to the spatial position of each array element in the receiving array, the sound source s received by each array element of the receiving array is respectively 0 The signal of (t) is subjected to spherical wave phase compensation according to the spatial position of the scanning point to obtain the compensation output at the scanning point, and the compensation output of each array element at the scanning point is weighted and summed to obtain the response of the receiving array to the sound wave at the scanning point. The focusing effect of the receiving array on the sound source at the scanning point at different spatial positions on the acoustic image scanning plane is obtained respectively, thereby obtaining the near-field directivity function. The explanation is as follows:

[0044] Located at the spatial position (x 0 ,y 0 ,z 0 ) and the distance between any n1th array element in the first single-line array The distance between the sound source 3 and the n2th array element in the second single-line array Among them, n1∈[1,N1], n2∈[1,N2], the spatial position of any n1th array element in the first single-line array is recorded as (x n1 ,y n1 ,z n1 ), the spatial position of any n2th array element in the second single-line array is recorded as (x n2 ,y n2 ,z n2 ). Then under ideal conditions, the sound source s received by the receiving array 0 The signal (t) can be expressed as A n1 is the sound source s received by the n1th array element in the first single-line array 0 (t) signal amplitude, A n2 is the sound source s received by the n2th array element in the second single-line array 0 (t) is the signal amplitude, and c is the speed of sound.

[0045] The distance between the scanning point at any spatial position (x, y, z) in the acoustic image scanning plane and any n1th array element in the first single-line array The distance between this scanning point and the n2th array element in the second single-line array The signals received by each array element are subjected to spherical wave phase compensation according to the spatial position (x, y, z) of the scanning point, and the outputs of each array element are weighted and summed. The dual-line array can be regarded as the superposition of the results of two single-line arrays. The beamforming output at the scanning point is: Since the sound source s 0 (t) and the scanning point are both located on the acoustic image scanning plane, so the sound source s 0 The Z-direction coordinate of the spatial position of (t) is equal to the Z-direction coordinate of the scanning point, both of which are scanning depth h. Therefore, the different spatial positions in this application actually refer to the different coordinates in the X-direction and Y-direction.

[0046] Then the response of the near-field directivity function of the receiving array to the sound wave at the scanning point of the spatial position (x, y, z) is:

[0047]

[0048] Based on the near-field directivity function of the receiving array, it can be seen that when the spatial position (x, y, z) of the scanning point and the sound source s 0 The spatial position (x) of (t) 0 ,y 0 ,z 0 ) coincide with each other, the phases of the array elements are superimposed in phase, and the response of the sound wave at the scanning point reaches its maximum value.

[0049] The calculated near-field directivity function of the receiving array and the spatial position of the sound source (x0 ,y 0 ,z 0 ) corresponds to different spatial positions (x 0 ,y 0 ,z 0 ) has a different function shape of the near-field directivity function of the sound source, resulting in the obtained near-field directivity function of the receiving array being a shift function.

[0050] Please refer to Figure 3-5 The simulation test results shown in FIG. 1 are in meters. For a sound source 3 whose spatial position is (10, -10, h), the near-field directivity function of the receiving array obtained based on the above method is shown in FIG. 1 at each scanning point. Figure 3 As shown, Figure 3 The dotted line in the middle is the peak position of the sound wave response. For the sound source 3 with the spatial position (10, 0, h), the near-field directivity function of the receiving array at each scanning point is shown in the following figure: Figure 4 As shown, Figure 4 The dotted line in the middle is the peak position of the sound wave response. For the sound source 3 with the spatial position (10,10,h), the near-field directivity function of the receiving array at each scanning point is shown in the following figure: Figure 5 As shown, Figure 5 The dotted line in the middle shows the peak of the sound wave response. Figure 3-5 It can be determined from the simulation result diagram that when the sound source 3 is located at different spatial positions, the shape of the corresponding near-field directivity function is different, which cannot be regarded as a shift of the natural directivity function, and the peak position of the response of each near-field directivity function sound wave corresponds to the spatial position of the sound source.

[0051] Step 140 , combining the received signals acquired by the receiving array with focused beamforming to obtain a sound source distribution map, where the sound source distribution map indicates the sound wave output at different spatial positions.

[0052] In one embodiment, the method for obtaining the sound source distribution map includes: according to the spatial position of each array element in the receiving array, performing spherical wave phase compensation on the received signals of each array element of the receiving array according to the spatial position of the scanning point, obtaining the compensation output at the scanning point, performing weighted summation on the compensation output of each array element at the scanning point, obtaining the sound wave output at the scanning point, and obtaining the sound wave output at each scanning point on the acoustic image scanning plane, thereby obtaining the sound source distribution map. The method for obtaining the sound source distribution map in this step is similar to step 120, except that in step 120, only one sound source s is used. 0 (t) scenario, and the receiving array may actually need to receive signals from I sound sources, each of which is located at a different spatial position and has a different sound source signal.

[0053] Located at the spatial position (x i ,y i ,z i ,) for any i-th sound source s i (t) The distance to the n1th element in the first single-line array The spatial position (x i ,y i ,z i ,) for any i-th sound source s i (t) The distance to the n2th element in the second single-line array By superimposing the signals of multiple sound sources, the received signal obtained by the receiving array can be expressed as A n1,i is the i-th sound source s received by the n1-th array element in the first single-line array i (t) signal amplitude, A n2,i is the i-th sound source s received by the n2-th array element in the second single-line array i (t) is the signal amplitude, i∈[1,I].

[0054] Similarly, the distance between a scanning point at any spatial position (x, y, z) in the acoustic image scanning plane and any n1th array element in the first single-line array is The distance between this scanning point and the n2th array element in the second single-line array The signal received by each array element is compensated for the spherical wave phase according to the spatial position (x, y, z) of the scanning point, and the output of each array element is weighted and summed. The dual-line array can be regarded as the superposition of the results of two single-line arrays. The beamforming output at any scanning point (x, y, z) in the sound source distribution diagram is obtained as follows: From this, we can get the sound wave output at any scanning point (x, y, z) in the sound source distribution diagram:

[0055]

[0056] Similarly, when the spatial position of the scanning point coincides with the spatial position of the sound source, the phases of the array elements are superimposed in phase, and the sound wave output at the scanning point reaches a peak value, which is generally reflected as a bright spot in the sound source distribution diagram. Since the receiving array in this application is a dual-line array, compared with a single-line array, it can solve the problem of port and starboard ambiguity, and has a certain port and starboard resolution capability, and can determine whether the sound source signal is on the port or starboard side of the receiving array.

[0057] Please refer to Figure 6 and 7 The simulation comparison diagram is shown in meters, assuming that there is only one sound source located at (0,10,h). Taking the first single-line array as an example, the sound source distribution diagram is as follows: Figure 6 As shown in FIG. 1 , two target sources of equal intensity appear in the sound source distribution diagram, located at (0,10,h) and (0,-10,h) respectively, as shown by the dotted line, resulting in the problem of port and starboard blur. When the receiving array of the dual-line array structure of the present application is used, the sound source distribution diagram obtained is as follows Figure 7 As shown, a target source with the largest sound wave output appears in the sound source distribution diagram at (0,10,h)(0,-10,h) as shown by the dotted line. In the sound source distribution diagram, the sound wave output at (0,10,h) is much greater than the sound wave output at (0,-10,h), so that a certain left and right side discrimination capability can be achieved.

[0058] Step 160 , performing a deconvolution operation on the sound source distribution diagram and the near-field directivity function of the receiving array to obtain a sound source localization result.

[0059] Please refer to Figure 7 In the simulation diagram shown, although the dual-line array can improve the left and right resolution to a certain extent, the location with the largest sound wave output in the sound source distribution diagram is usually an area with a large coverage area, so the positioning accuracy is low. Therefore, in this application, the sound source distribution diagram and the near-field directivity function of the receiving array are further deconvolved to obtain a more accurate sound source localization result.

[0060] As described above, the near-field directivity function of the receiving array in the present application is a shift function. In order to adapt to the characteristics of the shift function, in one embodiment, a two-dimensional extended RL algorithm is used to perform a deconvolution operation on the near-field directivity function of the receiving array of the sound source distribution diagram. Iterate the solution until the iteration termination condition is reached, and then the sound source localization result q obtained by the r+1th iteration is (r+1) (x,y) is used as the sound source localization result.

[0061] During the iteration process, when the predetermined number of iterations is reached, or the sound source localization result q obtained by the r+1th iteration is (r+1) (x, y) and the sound source localization result q obtained by the rth iteration (r) When the error between (x, y) is less than the error threshold, it is determined that the iteration termination condition is met.

[0062] Among them, q (r) (x,y) is the sound source localization result obtained by the rth iteration. represents the normalized acoustic wave output at any point (ξ,η) on the acoustic image scanning plane where the sound source and scanning point are located and B(ξ,η) is the sound wave output at (ξ,η) on the sound image scanning plane in the sound source distribution diagram, p(ξ,η|x,y) is the near-field directivity function at (ξ,η) on the acoustic image scanning plane, is the normalized near-field directivity function at (ξ,η) on the acoustic image scanning plane and

[0063] exist Figure 7 In the simulation example shown, the obtained Figure 7 The sound source localization result obtained by deconvolution operation of the sound source distribution diagram shown and the near-field directivity function of the receiving array is as follows Figure 8 As shown, the final sound source localization result is Figure 8 There is a bright spot at (0,10,h) in Figure 8 The bright spot in the white dotted frame is contrasted Figure 7 The result can only locate the area near (0,10,h). The sound source localization result obtained by this method is more accurate, has higher resolution, lower side lobes, and better weak target resolution.

[0064] The above is only a preferred embodiment of the present application, and the present application is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present application should be considered to be included in the protection scope of the present application.

Claims

1. A dual-line array focused beamforming passive positioning method based on deconvolution, characterized in that: The method comprises: A near-field directivity function of the receiving array is calculated according to the array parameters of the receiving array, wherein the near-field directivity function indicates the response of the receiving array to sound waves at different spatial positions, and the receiving array is a dual-line array structure, including two single-line arrays arranged in parallel and spaced apart; The received signals acquired by the receiving array are combined with focused beamforming to obtain a sound source distribution map, wherein the sound source distribution map indicates the sound wave output at different spatial positions; Performing a deconvolution operation on the sound source distribution diagram and the near-field directivity function of the receiving array to obtain a sound source localization result; The method for obtaining a sound source distribution diagram comprises: performing spherical wave phase compensation on the received signals of each array element of the receiving array according to the spatial position of each array element in the receiving array according to the spatial position of a scanning point, obtaining a compensation output at the scanning point, performing weighted summation on the compensation output of each array element at the scanning point, obtaining a sound wave output at the scanning point, respectively obtaining a sound wave output at each scanning point on a sound image scanning plane, obtaining the sound source distribution diagram, wherein the sound source and the scanning point are located on the same sound image scanning plane; the sound wave output at any scanning point in the sound source distribution diagram is obtained as follows: The first single-line array in the receiving array includes N1 array elements arranged at intervals, and the second single-line array includes N2 array elements arranged at intervals. n1,i is the i-th sound source s received by the n1-th array element in the first single-line array i (t) signal amplitude, A n2,i is the i-th sound source s received by the n2-th array element in the second single-line array i (t), i∈[1,I], where I is the number of sound sources involved, each of which is located at a different spatial position and has a different sound source signal; d n1 is the spatial position (x i ,y i ,z i ,) at the sound source s i (t) The distance to the n1th array element in the first single-line array, d n2 is the spatial position (x i ,y i ,z i ,) at the sound source s i (t) The distance to the n2th array element in the second single-line array, d′ n1 is the distance between the scanning point and the n1th array element in the first single-line array, d′ n2 is the distance from the scanning point to the n2th array element in the second single-line array, and c represents the speed of sound.

2. The method according to claim 1, characterized in that The near-field directivity function of the receiving array obtained by calculation corresponds to the spatial position of the sound source. The function shapes of the near-field directivity functions corresponding to sound sources at different spatial positions are different. The near-field directivity function of the receiving array is a shift function.

3. The method according to claim 2, characterized in that The method of performing a deconvolution operation on the sound source distribution diagram and the near-field directivity function of the receiving array comprises: A two-dimensional extended RL algorithm is used to perform a deconvolution operation on the near-field directivity function of the receiving array of the sound source distribution diagram.

4. The method according to claim 3, characterized in that Methods for obtaining sound source localization results using a two-dimensional extended RL algorithm include: according to Iterate the solution until the iteration termination condition is reached, and then the sound source localization result q obtained by the r+1th iteration is (r+1) (x, y) as the sound source localization result; Among them, q (r) (x,y) is the sound source localization result obtained by the rth iteration. represents the normalized acoustic wave output at any point (ξ,η) on the acoustic image scanning plane where the sound source and scanning point are located and B(ξ,η) is the sound wave output at (ξ,η) on the sound image scanning plane in the sound source distribution map, p(ξ,η|x,y) is the near-field directivity function at (ξ,η) on the acoustic image scanning plane, is the normalized near-field directivity function at (ξ,η) on the acoustic image scanning plane and 5. The method according to claim 4, characterized in that When the predetermined number of iterations is reached, or the sound source localization result q obtained by the r+1th iteration is (r+1) (x, y) and the sound source localization result q obtained by the rth iteration (r) When the error between (x, y) is less than the error threshold, it is determined that the iteration termination condition is met.

6. The method according to claim 1, characterized in that When calculating the near-field directivity function of the receiving array, the array parameters of the receiving array used include the number of array elements in the receiving array and the spatial position coordinates of each array element.

7. The method according to claim 2, characterized in that: The method for calculating the near-field directivity function corresponding to the receiving array and the sound source s0(t) at any spatial position (x0, y0, z0) includes: According to the spatial position of each array element in the receiving array, the signal of the sound source s0(t) received by each array element of the receiving array is respectively subjected to spherical wave phase compensation according to the spatial position of the scanning point to obtain the compensation output at the scanning point, and the compensation output of each array element at the scanning point is weighted summed to obtain the response of the receiving array to the sound wave at the scanning point; the focusing effect of the receiving array on the sound source at the scanning point at different spatial positions on the acoustic image scanning plane is respectively obtained to obtain the near-field directivity function, and the sound source and the scanning point are located in the same acoustic image scanning plane.

8. The method according to claim 7, characterized in that The response of the near-field directivity function of the receiving array to the sound wave at any scanning point is obtained as follows: The first single-line array in the receiving array includes N1 array elements arranged at intervals, and the second single-line array includes N2 array elements arranged at intervals. n1 is the signal amplitude of the sound source s0(t) received by the n1th array element in the first single-line array, A n2 is the signal amplitude of the sound source s0(t) received by the n2th array element in the second single-line array, d n1 is the distance between the sound source s0(t) at the spatial position (x0, y0, z0) and the n1th array element in the first single-line array, d n2 is the distance between the sound source s0(t) at the spatial position (x0, y0, z0) and the n2th array element in the second single-line array, d n '1 is the distance between the scanning point and the n1th array element in the first single-line array, d n '2 is the distance from the scanning point to the n2th array element in the second single-line array, and c represents the speed of sound.

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