A method for acoustic target positioning and an acoustic target detection device

Abstract

The present application relates to a kind of acoustic target positioning method and acoustic target detection device, it is related to target detection and acoustic measurement technical field.Positioning method is realized based on three-dimensional acoustic detection array, including horizontal detection array and vertical detection array, horizontal detection array includes the multiple circular ring detection array of multiple microphone, vertical detection array includes the linear detection array of multiple microphone, is arranged in the multiple circular ring detection array upper;For any one acoustic target, positioning method includes: obtaining the spatial position coordinate of each microphone;Determine reference microphone, estimate the acoustic signal delay time of other arbitrary microphone and reference microphone between acoustic signal at preset frequency, and calculate the distance difference of the preset frequency sound propagation of acoustic target radiation;Based on the minimum solution of the residual sum of squares of equation system, the spatial position of acoustic target is obtained.Compared with prior art, it can improve the resolution of pitch direction, and be suitable for unmanned aerial vehicle detection demand.

Description

Technical Field

[0001] This invention relates to the fields of target detection and acoustic measurement technology, specifically to a method for locating acoustic targets and a device for detecting acoustic targets. Background Technology

[0002] Helicopters, drones, and other low-altitude aircraft typically utilize terrain features to fly at low altitudes, effectively evading radar and optoelectronic equipment detection, posing a serious safety threat to the public. However, the noise emitted by low-altitude aircraft is readily detectable by acoustic instruments and even the human ear. Acoustic target detection is currently an effective means of countering the threat posed by low-altitude aircraft. Acoustic target detection arrays are key equipment in acoustic target detection, and high integration, flexible deployment, and ease of use are the design goals of acoustic target detection arrays.

[0003] In current acoustic target detection arrays, individual arrays, such as planar arrays, are mainly used for acoustic target direction finding. However, they have low resolution in the pitch direction and require rotating the microphone array to achieve target detection. Therefore, it is necessary to optimize the acoustic target detection array structure, develop single-array localization methods, and improve the performance and applicability of acoustic target detection arrays to support the safety flight monitoring needs of the rapidly emerging low-altitude economic low-altitude aircraft. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide a method for locating acoustic targets and an acoustic target detection device, which can improve pitch resolution and positioning efficiency and is suitable for UAV detection.

[0005] In a first aspect, one embodiment provides a method for locating acoustic targets, based on a three-dimensional acoustic detection array. The three-dimensional acoustic detection array includes a horizontal detection array and a vertical detection array. The horizontal detection array includes a multi-ring detection array composed of multiple microphones, and the vertical detection array includes a linear detection array composed of multiple microphones positioned above the multi-ring detection array. For any acoustic target, the method for locating the acoustic target includes:

[0006] Obtain the spatial coordinates of each microphone;

[0007] Determine a reference microphone and estimate the acoustic signal delay time between any other microphone and the reference microphone at a preset frequency.

[0008] Based on the acoustic signal delay time, calculate the distance difference between the sound of the preset frequency radiated by the acoustic target propagating to any other microphone and the distance propagating to the reference microphone.

[0009] The spatial position of the acoustic target is obtained by minimizing the sum of squared residuals of the equation system. Any one of the equations in the equation system is an equation established based on the spatial position coordinates of the reference microphone and any other microphone, the distance difference between the sound radiated by the acoustic target at a preset frequency and the distance to the other microphone and the distance to the reference microphone, and the propagation geometry of the sound radiated by the acoustic target.

[0010] Secondly, in one embodiment, an acoustic target detection device is provided, which detects acoustic targets based on the above-mentioned acoustic target positioning method. The device includes a three-dimensional acoustic detection array, a GPS positioning module, a wireless communication module, a data acquisition module, and a cylindrical housing.

[0011] The three-dimensional acoustic detection array includes a vertical microphone arm and multiple horizontal microphone arms. The microphones are mounted on the microphone arms via mounting bases. The vertical microphone arm is coaxial with the cylindrical housing to facilitate the extension of the vertical microphone arm out of the cylindrical housing. The extended vertical microphone arm is locked by a clamp provided on the top cover plate of the cylindrical housing. The multiple horizontal microphone arms are evenly distributed in the same horizontal plane. The root of each horizontal microphone arm is connected to the top cover plate of the cylindrical housing via a hinge and a telescopic support rod, so that the horizontal microphone arm is perpendicular to the axis of the cylindrical housing after being adjusted into position.

[0012] The GPS positioning module includes a base station located at the end of the vertical microphone arm and a rover station located at the end of each horizontal microphone arm to obtain GPS coordinates.

[0013] The data acquisition module employs multi-channel synchronous data acquisition to achieve synchronous acquisition of sound signals from all microphones;

[0014] The wireless communication module is used to realize long-distance wireless transmission of the collected sound signals and GPS positioning data.

[0015] The beneficial effects of this invention are:

[0016] The three-dimensional acoustic detection array includes a horizontal detection array and a vertical detection array. The horizontal detection array comprises a multi-ring detection array consisting of multiple microphones, while the vertical detection array includes a linear detection array consisting of multiple microphones positioned above the multi-ring array. This allows any horizontal linear detection array to form an L-shaped array with the vertical linear detection array, improving lateral resolution in the pitch direction. Consequently, high-precision detection of a large area of ​​acoustic targets can be achieved without rotating the microphone array during use. Furthermore, the positioning method is based on minimizing the sum of squared residuals of a system of equations to obtain the spatial position of the acoustic target. Each equation in this system is based on the spatial coordinates of a reference microphone and any other microphone, the distance difference between the propagation of the target's radiated sound at a preset frequency to any other microphone and to the reference microphone, and the propagation geometry of the target's radiated sound. This allows the positioning method to be suitable for time delay estimation methods in complex environments and for nonlinear equations relating the spatial position of acoustic targets, thereby improving the positioning accuracy of acoustic targets. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an acoustic target detection device according to an embodiment of this application;

[0018] Figure 2 This is a partial structural schematic diagram of a acoustic target detection device according to an embodiment of this application;

[0019] Figure 3 This is a schematic diagram of a horizontal microphone arm support structure according to an embodiment of this application;

[0020] Figure 4 This is a schematic flowchart of a method for optimizing the spatial position setting of microphones in a three-dimensional acoustic detection array according to an embodiment of this application;

[0021] Figure 5 This is a schematic flowchart of a sound target localization method according to an embodiment of this application;

[0022] Figure 6 This is a schematic diagram of the propagation of sound waves radiated by an acoustic target to a three-dimensional acoustic detection array according to an embodiment of this application.

[0023] In the diagram: 1. Vertical microphone arm, 2. Horizontal microphone arm, 3. Microphone, 4. Mounting base, 5. Microphone slot, 6. Arm clamp, 7. Base station, 8. Rover station, 9. Transmitter directional antenna, 10. Power module, 11. Data acquisition module, 12. Columnar housing, 13. Leg, 14. Two-axis level, 15. Hinge, 16. Telescopic support rod. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0025] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0026] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0027] In view of the problems of the prior art, this application provides a method for locating acoustic targets and an acoustic target detection device, which is based on a three-dimensional acoustic detection array. Since the three-dimensional acoustic detection array includes a horizontal detection array and a vertical detection array, wherein the horizontal detection array includes a multi-ring detection array composed of multiple microphones, and the vertical detection array includes a linear detection array composed of multiple microphones positioned above the multi-ring detection array, any horizontal linear detection array can form an L-shaped array with the vertical linear detection array, improving the lateral resolution in the pitch direction. Therefore, high-precision detection of a wide range of acoustic targets can be achieved without rotating the microphone array during use. Furthermore, in the positioning method, the spatial position of the acoustic target is obtained by minimizing the sum of squared residuals of the equation system. Each equation in the equation system is based on the spatial coordinates of the reference microphone and any other microphone, the distance difference between the sound radiated by the acoustic target at a preset frequency and the distance to the other microphone and the reference microphone, and the propagation geometry of the sound radiated by the acoustic target. This makes the positioning method of this application suitable for time delay estimation methods in complex environments and for nonlinear equation systems of the spatial position of the acoustic target, thereby improving the positioning accuracy of the acoustic target.

[0028] For ease of understanding, the acoustic target detection device of the present application embodiment will be described below.

[0029] An embodiment of this application provides an acoustic target detection device, which includes a three-dimensional acoustic detection array, a GPS positioning module, a wireless communication module, a data acquisition module, and a cylindrical housing.

[0030] Please refer to Figure 1 and Figure 2 The three-dimensional acoustic detection array includes a vertical microphone arm 1 and multiple horizontal microphone arms 2. Microphones 3 are mounted on the microphone arms (including the vertical microphone arm 1 and the horizontal microphone arms 2) via mounting bases 4. The vertical microphone arm 1 is coaxial with the cylindrical housing 12, allowing it to extend beyond the housing 12. A clamp 6 on the top cover of the housing 12 secures the extended vertical microphone arm 1. The multiple horizontal microphone arms 2 are evenly distributed in the same horizontal plane. (Please refer to...) Figure 3 The root of each horizontal microphone arm 2 is connected to the top cover of the cylindrical housing 12 via a hinge 15 and a telescopic support rod 16, so that the horizontal microphone arm 2 is perpendicular to the axis of the cylindrical housing 12 after being adjusted into place.

[0031] In this embodiment, an odd number of horizontal microphone arms 2 are used to solve the problem of low spatial resolution caused by symmetry failure when there are even numbers. In one specific implementation of this application, there are 5 horizontal microphone arms. In other embodiments, there may be 3, 7, 9, etc.

[0032] Since the base of each horizontal microphone arm 2 is connected to the top cover of the cylindrical housing 12 via hinges 15 and telescopic struts 16, the multiple horizontal microphone arms 2 are arranged radially. Each horizontal microphone arm 2 is equipped with the same number of microphones 3, and the microphones 3 on each horizontal microphone arm 2 are positioned in the same location, so that the horizontal detection array includes a multi-ring detection array composed of multiple microphones 3. Furthermore, since the vertical microphone arm 1 is coaxial with the cylindrical housing 12, and the horizontal microphone arms 2 are perpendicular to the axis of the cylindrical housing 12 after adjustment, the multiple microphones 3 on the vertical microphone arm 1 form a linear detection array, located above the multi-ring detection array. This allows any horizontal linear detection array to form an L-shaped array with the vertical linear detection array, improving the lateral resolution in the pitch direction. Thus, high-precision detection of a large range of targets can be achieved without rotating the microphone array during use.

[0033] In one embodiment, the number of microphones 3 installed on the vertical microphone arm 1 is the same as that installed on any horizontal microphone arm 2.

[0034] The applicant discovered in their research that the spatial position of each microphone in a three-dimensional acoustic detection array has a significant impact on the direction finding and localization performance of acoustic targets. To improve the direction finding and localization efficiency of a three-dimensional acoustic detection array, this application provides a method for optimizing the spatial position of each microphone in the array, setting each microphone based on the optimized spatial position. Please refer to... Figure 4 The optimization method includes:

[0035] Step S10: Construct an optimized model for the three-dimensional acoustic detection array.

[0036] Let the spatial coordinates of the microphone in the three-dimensional acoustic detection array be... ,in, m Represents the index of any microphone, 1 ≤ m ≤ M , M P represents the total number of microphones, and P represents the spatial coordinate matrix of the microphones. Represents any microphone m Spatial location coordinates, T This indicates transpose.

[0037] If there is a frequency in space... f The reference plane acoustic wave is incident on the three-dimensional acoustic detection array at an angle of incidence of θ. The wavenumber vector of the reference incident sound wave is ,in, Indicates the pitch angle of the incident sound wave. Let represent the azimuth angle of the incident sound wave. Then, the array response of this three-dimensional acoustic detection array can be expressed as:

[0038] ;

[0039] ;

[0040] ;

[0041] in, The modulus of a complex number, This represents the response value of all microphones to the incident sound wave. This represents the wavenumber vector of the reference incident sound wave. Let exp denote the wavenumber vector of any incident sound wave, and let exp denote the expression in terms of natural numbers. e Logarithm with base 0, i represents an imaginary number, c Indicates the speed of sound. Represents pi (π). Represents the pitch angle of any incident sound wave. It represents the azimuth angle of any incident sound wave.

[0042] The optimized model of the three-dimensional acoustic detection array can then be obtained, which can be expressed as:

[0043] ;

[0044] in, and These represent the preset minimum pitch angle and maximum pitch angle, respectively. and These represent the preset minimum and maximum azimuth angles, respectively.

[0045] The constraints of the above-mentioned three-dimensional acoustic detection array optimization model include:

[0046] ;

[0047] in, This represents the main lobe width of the three-dimensional acoustic detection array. This indicates the upper limit of the preset three-dimensional acoustic detection array main lobe. E These are constants related to the array configuration of the three-dimensional acoustic detection array. R This indicates the preset detection distance. D This indicates the aperture of the three-dimensional acoustic detection array. Indicates the wavelength of the sound wave being detected.

[0048] Step S20: Optimize the spatial position of each microphone in the three-dimensional acoustic detection array based on the three-dimensional acoustic detection array optimization model.

[0049] Based on the three-dimensional acoustic detection array optimization model obtained in step S10, the spatial position of each microphone in the three-dimensional acoustic detection array can be solved by using the conjugate gradient method or particle swarm optimization algorithm, thereby obtaining the optimal position of each microphone.

[0050] Based on the spatial position of each microphone in the three-dimensional acoustic detection array obtained from the above-mentioned optimized model, the three-dimensional spatial lateral and positioning resolution of the acoustic target is improved, thereby obtaining a more accurate acoustic target position.

[0051] In one embodiment of this application, each microphone arm is provided with a microphone slot 5 corresponding to a microphone, so that the microphone can be folded into the microphone slot 5. The mounting base 4 allows the microphone to be quickly unfolded or folded into the microphone slot 5. In addition, an adjustment and limiting device is provided to ensure that the microphone 3 is perpendicular to the microphone arm when unfolded.

[0052] Based on the above embodiments, the three-dimensional acoustic detection array in this application has multiple microphones arranged in a horizontal plane, which takes into account the performance of a planar array. At the same time, any horizontal microphone arm and a vertical microphone arm can form a vertical L-shaped matrix, which improves the lateral resolution in the pitch direction. It does not require rotating the acoustic array during use, thus improving the spatial lateral performance of the three-dimensional acoustic detection array.

[0053] In the embodiments of this application, the GPS positioning module includes a base station 7 located at the end of the vertical microphone arm 1 and a rover 8 located at the end of each horizontal microphone arm 2 to obtain GPS coordinates. During use, both the base station and the rover are vertically oriented to ensure the accuracy of GPS signal reception and positioning.

[0054] In the embodiments of this application, the data acquisition module 11 adopts multi-channel synchronous data acquisition to achieve synchronous acquisition of sound signals from all microphones.

[0055] In one embodiment of this application, the data acquisition module 11 can be placed above the power supply module 10 for easy power supply. The power supply module 10 can be placed at the bottom of the housing, with sealed and shock-absorbing treatment, and a charging interface is provided on the surface of the housing.

[0056] In the embodiments of this application, the wireless communication module is used to realize long-distance transmission of the collected acoustic signals and GPS positioning data.

[0057] In one embodiment of this application, the transmitting directional antenna 9 of the wireless communication module is mounted on the top of the cylindrical housing 12, and the receiving directional antenna is configured according to user requirements. Those skilled in the art will understand that the transmitting and receiving directional antennas must be arranged facing each other, and there must be no obstructions between them.

[0058] In some embodiments of this application, three retractable and foldable support legs 13 are installed at the lower part of the cylindrical housing, and a two-axis level 14 is installed on the top cover. The height of the support legs 13 can be flexibly adjusted and fixed, facilitating flexible adjustment of the housing on complex terrain to keep the upper surface of the housing level and improve the spatial positioning accuracy of the three-dimensional sound array. The measurement cables of the microphone and GPS positioning module are connected to the data acquisition module 11 and the power module 10 through the wiring channels inside the support arm and the cylindrical housing 12, and waterproof and dustproof treatment is applied to key parts.

[0059] The acoustic target localization method provided in this application embodiment can be implemented based on the acoustic target detection device provided in any of the above embodiments. Please refer to... Figure 5 The acoustic target localization method may include:

[0060] Step S100: Obtain the spatial coordinates of each microphone.

[0061] As one embodiment of this application, a three-dimensional acoustic detection array coordinate system can be established. Please refer to [reference needed]. Figure 6 This coordinate system is defined based on the structure of the three-dimensional acoustic detection array itself, with the origin at... O Located at the center of the three-dimensional acoustic detection array, which is positioned at the intersection of all microphone arms, the X-axis points to a pre-defined horizontal microphone arm, the Z-axis points vertically upward, and the Y-axis is determined by the right-hand rule. Based on the known positional relationships between the microphones, the spatial coordinates of each microphone in the three-dimensional acoustic detection array coordinate system can be obtained.

[0062] Step S200: Determine the reference microphone and estimate the acoustic signal delay time between any other microphone and the reference microphone at a preset frequency.

[0063] This application presents a novel method for estimating the acoustic signal delay time. In this method, the acoustic signal delay time is obtained by solving for the maximum value of a weighted generalized cross-correlation function; where the weighting coefficients include both signal-to-noise ratio (SNR) and reverberation noise. This allows the estimation of the acoustic signal delay time to comprehensively consider the effects of high SNR and reverberation noise, thus enabling the construction of an acoustic signal delay time estimate suitable for complex environments.

[0064] The following section provides a detailed introduction to the novel acoustic signal delay time estimation method.

[0065] Please refer to Figure 6 Assuming the acoustic target S n ( For the sound target S n The angle of incidence of the sound wave radiated by the projection of the horizontal detection array onto the plane of the horizontal detection array in the three-dimensional acoustic detection array is: ,in, and They represent the first n The elevation and azimuth angles of the three-dimensional acoustic detection array incident on the sound waves radiated by the acoustic target, 1≤ n ≤ N , N This represents the total number of acoustic targets. Based on the theory of planar sound wave propagation, the number of targets in a three-dimensional acoustic detection array is... m A microphone t Sound pressure signal received at any time It can be represented as:

[0066] ;

[0067] in, Indicates the first n The intensity of the acoustic signal radiated by a single acoustic target Indicates the first n The angular frequency of the sound waves radiated by a sound target Indicates the first n The sound target to the first m The propagation time of each microphone Indicates the first m The noise signal measured by each microphone. Then, It can be represented as:

[0068] .

[0069] Let the third sound in the three-dimensional acoustic detection array be... m The and the first m + j (1- m ≤ j ≤ M - m The sound pressure signals received by the sound source by the microphones are respectively and Its generalized cross-spectral power function is:

[0070] ;

[0071] in, express and The generalized cross-power spectral function between them; This represents a weighting function to adapt to environments with low signal-to-noise ratios and severe echoes; and They represent and Fourier transform, e Represents natural numbers, d To represent the differential, Indicates conjugate. Then we have:

[0072] ;

[0073] ;

[0074] in, This represents the weighting coefficient, which is related to the signal-to-noise ratio (SNR), and 0 ≤ ≤1, The scaling factor representing the ratio of background noise to reverberation noise, 0 ≤ ≤1, This is an intermediate quantity; Indicates sound pressure signal The self-power spectrum, ; Indicates sound pressure signal and The cross power spectrum between them ; Indicates sound pressure signal The self-power spectrum, .

[0075] Therefore, we can obtain The maximum value of is the sound propagation delay between any two microphones.

[0076] Step S300: Based on the acoustic signal delay time, calculate the distance difference between the sound of the preset frequency radiated by the acoustic target propagating to any other microphone and the distance propagating to the reference microphone.

[0077] By pre-setting a microphone as a reference microphone, the spatial coordinates of the reference microphone can be obtained. The following will use the first... u (1≤ u ≤ M The following explanation will be based on a single microphone as a reference microphone.

[0078] Let the spatial coordinates of the acoustic target be... Any microphone m Spatial position coordinates are The origin of the coordinate system and any microphone m The distance is The sound radiated from the target at a preset frequency propagates to any other microphone. m With propagation to the reference microphone u Distance difference ,in m ≠ u Then any other microphone m With reference microphone u The delay time of the sound signal at the preset frequency is Then there is .

[0079] Step S400: Minimize the sum of squared residuals of the equation set to obtain the spatial position of the acoustic target. Each equation in the equation set is established based on the spatial coordinates of the reference microphone and any other microphone, the distance difference between the distance the sound radiated by the acoustic target at a preset frequency propagates to any other microphone and to the reference microphone, and the propagation geometry of the sound radiated by the acoustic target.

[0080] Based on the geometric relationship of sound wave propagation, the coordinates of the sound target, the first... m The microphone is relative to the first u The sound propagation delay of each microphone is Then we have:

[0081] ;

[0082] ;

[0083] ;

[0084] in, Represents the spatial coordinates of the acoustic target. Indicates reference microphone u Spatial location coordinates, Indicates any other microphone m Spatial location coordinates, and All are intermediate quantities. This indicates the coordinate system origin and any microphone. m The distance between them Indicates the coordinate system origin and reference microphone. u The distance between them.

[0085] set up Then, the spatial location of the acoustic target can be obtained by minimizing the sum of squared residuals of the system of equations, which can be expressed as:

[0086] ;

[0087] in, Represents the matrix of the system of equations. Represents the modulus of a matrix. Indicates a reference microphone u any other microphone m Distance difference Equations were established based on the geometric relationship of sound propagation from the target acoustic radiation.

[0088] In the above specific implementation, since the acoustic target localization result is based on the three-dimensional acoustic detection array coordinate system, it is necessary to transform the three-dimensional acoustic detection array coordinate system to the GPS coordinate system in order to achieve the fusion of the acoustic target localization result and geographical location information. Therefore, the acoustic target localization method of this application further includes:

[0089] Step S500: Convert the spatial coordinates of the acoustic target into GPS coordinates.

[0090] The GPS coordinate system is a geocentric-fixed (ECEF) coordinate system, with the origin located at the Earth's center of mass. The Z-axis points towards the North Pole along the Earth's rotation axis, the X-axis points to the intersection of the Prime Meridian (0° longitude) and the equator, and the Y-axis is determined by the right-hand rule. Since the coordinate system of the three-dimensional acoustic target detection array is not consistent with the GPS coordinate system, a coordinate transformation is required. Let the coordinate system of the acoustic target detection array be denoted as coordinate system [missing information]. I GPS coordinate system is a coordinate system J The coordinate transformation relationship between the two coordinates is:

[0091] ;

[0092] ;

[0093] in, coordinate system I coordinates in coordinate system J In the coordinates, R is a 3×3 rotation matrix and S is a 3×1 translation matrix; This is a coordinate transformation matrix, which can be used to calculate the transformation from a coordinate system. I To coordinate system J Coordinate transformation.

[0094] coordinate transformation matrix The key to the coordinate transformation of acoustic targets is the three-dimensional acoustic detection array based on this application, which is also a technical challenge. As a specific implementation of this application, a method for obtaining the coordinate transformation matrix is ​​provided. The specific method, which is based on setting up three or more non-collinear rover stations, includes:

[0095] Step S1000: Calculate the center of the rover.

[0096] In one embodiment, step S1000 can be represented as:

[0097] ;

[0098] ;

[0099] in, hIndicates the index of the rover station. H Indicates the number of mobile stations, 1 ≤ h ≤ H , Represents any rover station h In coordinate system I coordinates Represents any rover station h In coordinate system J coordinates Represents all rover stations in the coordinate system I The center coordinates, Represents all rover stations in the coordinate system J The center coordinates.

[0100] Step S2000: Obtain the decentralized coordinates of each rover station.

[0101] In one embodiment, step S2000 can be represented as:

[0102] ;

[0103] ;

[0104] in, Represents any rover station h In coordinate system I Decentralized coordinates Represents any rover station h In coordinate system J Decentralized coordinates.

[0105] Step S3000: Based on the decentralized coordinates of any rover station in the two coordinate systems, calculate the covariance matrix of all rover stations.

[0106] In one embodiment, step S3000 can be represented as:

[0107] ;

[0108] in, This represents the covariance matrix of all rover stations.

[0109] Step S4000: Perform singular value decomposition on the covariance matrix.

[0110] In one embodiment, step S4000 can be represented as:

[0111] ;

[0112] The U matrix determines the direction of the data; The matrices are singular values, which determine the strength of the data in each direction; the V matrix is ​​orthogonal to the U matrix and is used to help define the spatial structure.

[0113] Step S5000: Calculate the rotation matrix and translation matrix.

[0114] In one embodiment, step S5000 can be represented as:

[0115] ;

[0116] ;

[0117] in, Represents the rotation matrix. This represents the translation matrix.

[0118] It is important to note that when calculating the rotation matrix, you need to first determine whether the determinant of the rotation matrix is ​​equal to -1. If it is equal to -1, it means that the obtained rotation matrix is ​​a reflection matrix, and you need to take the negative value of the last column of the V matrix to correct it.

[0119] Step S6000: Obtain the coordinate transformation matrix.

[0120] Based on the rotation and translation matrices obtained above, the transformation matrix from coordinate system I to coordinate system B can be calculated. .

[0121] The above method converts the spatial coordinates of the acoustic target into GPS coordinates, thereby integrating the acoustic target location results with geographical location information and improving the applicability of acoustic target detection.

[0122] One embodiment of this application provides a computer-readable storage medium storing a program, the stored program including methods that can be loaded by a processor and processed in any of the above embodiments.

[0123] Those skilled in the art will understand that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, which may include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to achieve the above functions. For example, the program can be stored in the memory of a device, and when the program in the memory is executed by the processor, all or part of the above functions can be achieved. In addition, when all or part of the functions in the above embodiments are implemented by computer programs, the program can also be stored in a server, another computer, disk, optical disk, flash drive, or external hard drive, etc., and can be downloaded or copied to the memory of a local device, or the system of the local device can be updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be achieved.

[0124] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A method for locating acoustic targets, characterized in that, This is achieved using a three-dimensional acoustic detection array, which includes a horizontal detection array and a vertical detection array. The horizontal detection array includes a multi-ring detection array composed of multiple microphones, and the vertical detection array includes a linear detection array composed of multiple microphones positioned above the multi-ring detection array. The horizontal detection array includes multiple radially arranged, uniformly distributed horizontal microphone arms, each with the same number of microphones. The vertical detection array is positioned on a vertical microphone arm that radiates vertically upwards from the center of the rings, and the vertical microphone arm has the same number of microphones as any horizontal microphone arm. For any acoustic target, the acoustic target localization method includes: Obtain the spatial coordinates of each microphone; Determine a reference microphone and estimate the acoustic signal delay time between any other microphone and the reference microphone at a preset frequency. Based on the acoustic signal delay time, calculate the distance difference between the sound of the preset frequency radiated by the acoustic target propagating to any other microphone and the distance propagating to the reference microphone. The spatial position of the acoustic target is obtained by minimizing the sum of squared residuals of the equation system. Any one of the equations in the equation system is an equation established based on the spatial position coordinates of the reference microphone and any other microphone, the distance difference between the sound of the preset frequency radiated by the acoustic target propagating to any other microphone and to the reference microphone, and the propagation geometry of the sound radiated by the acoustic target. The method further includes optimizing the spatial position of each microphone in the three-dimensional acoustic detection array, and setting each microphone based on the optimized microphone spatial position. The optimization method includes: calculating the response of the three-dimensional acoustic detection array, constructing a three-dimensional acoustic detection array optimization model, and optimizing the spatial position of each microphone in the three-dimensional acoustic detection array based on the three-dimensional acoustic detection array optimization model. The three-dimensional acoustic detection array optimization model can be expressed as: ； ； ； ； in, Represents the pitch angle of any incident sound wave. and These represent the preset minimum pitch angle and maximum pitch angle, respectively. This represents the azimuth angle of any incident sound wave. and These represent the preset minimum and maximum azimuth angles, respectively. The modulus of a complex number, This represents the response value of all microphones to any incident sound wave. This represents the wavenumber vector of the reference incident sound wave. Denotes the wavenumber vector of any incident sound wave. m Represents the index of any microphone, 1 ≤ m ≤ M , M The total number of microphones is represented by exp, which is a natural number. e Logarithm with base 0, i represents an imaginary number, Indicates the first m The spatial coordinates of each microphone c Indicates the speed of sound. and These represent the elevation and azimuth angles of the incident sound wave, respectively. f Indicates the frequency of the incident sound wave. Represents pi; The constraints of the optimized model for the three-dimensional acoustic detection array include: ； in, This represents the main lobe width of the three-dimensional acoustic detection array. This indicates the upper limit of the preset three-dimensional acoustic detection array main lobe. E These are constants related to the array configuration of the three-dimensional acoustic detection array. R This indicates the preset detection distance. D This indicates the aperture of the three-dimensional acoustic detection array. Indicates the wavelength of the sound wave being detected.

2. The acoustic target localization method as described in claim 1, characterized in that, The estimation of the acoustic signal delay time at a preset frequency between any other microphone and the reference microphone includes: obtaining it by solving for the maximum value of the weighted generalized cross-correlation function; wherein the weighting coefficients include the signal-to-noise ratio and reverberation noise; the calculation of the distance difference between the sound radiated from the acoustic target at the preset frequency propagating to any other microphone and propagating to the reference microphone includes: ； in, m Represents the index of any microphone, 1 ≤ m ≤ M , M Indicates the total number of microphones. u This represents the index of the preset reference microphone among all microphones, 1≤ u ≤ M , u ≠ m , The preset frequency of sound radiation from the target is used to propagate to any other microphone. m With propagation to the reference microphone u The distance difference Indicates any other microphone m With reference microphone u The delay time of the sound signal at the preset frequency. c It indicates the speed of sound.

3. The acoustic target localization method as described in claim 2, characterized in that, The method of obtaining the spatial location of the acoustic target by minimizing the sum of squared residuals of the equation system includes: ； ； ； ； in, Represents the matrix of the system of equations. Represents the modulus of a matrix. The modulus of a complex number, Represents the spatial coordinates of the acoustic target. Indicates a reference microphone u any other microphone m Distance difference The equations establishing the geometric relationships of sound propagation from the target acoustic radiation are as follows: Indicates reference microphone u Spatial location coordinates, Indicates any other microphone m Spatial location coordinates, and All are intermediate quantities. This indicates the coordinate system origin and any microphone. m The distance between them Indicates the coordinate system origin and reference microphone. u The distance between them.

4. The acoustic target localization method as described in claim 1, characterized in that, The method further includes: converting the spatial coordinates of the acoustic target into GPS coordinates, based on a GPS module, wherein the GPS module includes a base station and a rover station, wherein the base station is located at the end of the vertical microphone arm and the rover station is located at the end of each horizontal microphone arm; the method for converting the spatial coordinates of the acoustic target into GPS coordinates includes: ； ； in, coordinate system I coordinates in coordinate system J Coordinates in, coordinate system I Let the coordinate system be the coordinate system of the acoustic target detection array. J Let R be a 3×3 rotation matrix and S be a 3×1 translation matrix, which is a GPS coordinate system. This is the coordinate transformation matrix, used to calculate the transformation from the coordinate system. I To coordinate system J Coordinate transformation.

5. The acoustic target localization method as described in claim 4, characterized in that, Methods for calculating coordinate transformation matrices include: The center of the computational rover station; Obtain the decentralized coordinates of each rover station; Calculate the covariance matrix of all rover stations based on the decentralized coordinates of any rover station in the two coordinate systems. Perform singular value decomposition on the covariance matrix; Calculate the rotation and translation matrices; Obtain the coordinate transformation matrix.

6. A sound target detection device, characterized in that, The sound target localization method according to any one of claims 1 to 5 is used to detect sound targets. The device includes a three-dimensional sound detection array, a GPS positioning module, a wireless communication module, a data acquisition module, and a cylindrical housing. The three-dimensional acoustic detection array includes a vertical microphone arm and multiple horizontal microphone arms. The microphones are mounted on the microphone arms via mounting bases. The vertical microphone arm is coaxial with the cylindrical housing to facilitate the extension of the vertical microphone arm out of the cylindrical housing. The extended vertical microphone arm is locked by a clamp provided on the top cover plate of the cylindrical housing. The multiple horizontal microphone arms are evenly distributed in the same horizontal plane. The root of each horizontal microphone arm is connected to the top cover plate of the cylindrical housing via a hinge and a telescopic support rod, so that the horizontal microphone arm is perpendicular to the axis of the cylindrical housing after being adjusted into position. The GPS positioning module includes a base station located at the end of the vertical microphone arm and a rover station located at the end of each horizontal microphone arm to obtain GPS coordinates. The data acquisition module employs multi-channel synchronous data acquisition to achieve synchronous acquisition of sound signals from all microphones; The wireless communication module is used to realize long-distance wireless transmission of the collected sound signals and GPS positioning data.

7. The acoustic target detection device as described in claim 6, characterized in that, Each microphone arm has a microphone slot that corresponds to a microphone, so that the microphone can be folded into the microphone slot.

Images