Target detection method and device, storage medium and electronic equipment

Abstract

The invention discloses a target detection method and device, a storage medium and electronic equipment. The method comprises the steps of determining each target array element in the towed linear array sonar, processing signal information received by each target array element to generate a target beam pattern, and processing signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern. And then, according to the target beam pattern, adjusting the basic beam pattern to obtain a final beam pattern, and according to the final beam pattern, carrying out target detection.

Description

Technical Field

[0001] The present invention relates to the field of sonar signal processing, and in particular to a target detection method, device, storage medium and electronic device. Background Art

[0002] Sonar is an electronic device that uses underwater sound waves to detect and locate underwater target devices. It is divided into active and passive types. The active type is that after the sound waves are emitted, they are reflected back when they encounter the target device. After the receiver receives the echo, the direction and distance of the target device can be known through data analysis and comparison. The passive type does not emit sound waves, but relies on receiving the sound of the target device's propeller rotation or other mechanical work to detect the target device.

[0003] In the application of passive towed linear array sonar, hydrophones are embedded in cables to form a linear array. The towed cable is dragged in the water behind the stern of the ship to detect the sound waves of the target equipment. It is mainly used to monitor the noise of submarines for long-range surveillance, direction finding, identification, ranging, etc.

[0004] The operating frequency band of the towed linear array sonar covers multiple octaves. In order to avoid the direction estimation error caused by the grating lobe effect, when the towed linear array sonar works omnidirectionally, the distance between adjacent array elements in the linear array must meet the condition of being less than the half wavelength corresponding to the sound wave. Therefore, the towed linear array sonar is usually composed of several sub-arrays, and the array element spacing in each sub-array is different. Each sub-array corresponds to a certain octave in the operating frequency band of the towed linear array sonar. Among them, the grating lobe effect refers to the phenomenon that in the radiation or reception process of the linear array or ultrasonic probe, in addition to the main lobe (i.e., the beam in the direction of maximum radiation or reception), a strong radiation or reception beam is formed in other directions. These additional beams are called grating lobes. Simply put, when the signal received by the towed linear array generates a beam pattern, a signal appears in the direction with a directional angle of 30 degrees. Due to the existence of the grating lobe effect, a signal may also appear in the direction with a directional angle of 60 degrees, resulting in the inability to identify the direction of the target device.

[0005] That is to say, the towed linear array sonar is composed of several array elements, and the distance between the array elements gradually increases or decreases. For lower frequency signals, the longer the wavelength, the more available array elements in the linear array that meet the requirement that the distance between adjacent array elements is less than half a wavelength. For higher frequency signals, the shorter the wavelength, the fewer available array elements in the linear array that meet the requirement that the distance between adjacent array elements is less than half a wavelength.

[0006] Therefore, for high-frequency signals, the existing technology cannot obtain an accurate beam pattern, and thus cannot perform effective detection.

[0007] Based on this, how to improve the accuracy of the beam pattern to improve the detection performance of the towed linear array sonar is an urgent problem to be solved. Summary of the invention

[0008] This specification provides a target detection method, device, storage medium and electronic device to partially solve the above-mentioned problems existing in the prior art.

[0009] This manual adopts the following technical solutions:

[0010] This specification provides a target detection method, including:

[0011] Determining target array elements in a towed linear array sonar, wherein the target array elements refer to array elements in the towed linear array sonar for receiving signals of a preset frequency, and the array elements in the towed linear array sonar are arranged in a linear manner;

[0012] Processing the signal information received by each target array element to generate a target beam diagram, and processing the signal information received by all array elements in the towed linear array sonar to generate a basic beam diagram, wherein the target beam diagram is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam diagram is used to characterize the intensity distribution of the signal received by all array elements in the towed linear array sonar in an omnidirectional angle;

[0013] According to the target beam pattern, the basic beam pattern is adjusted to obtain a final beam pattern;

[0014] Target detection is performed according to the final beam pattern.

[0015] Optionally, determining each target array element in the towed linear array sonar specifically includes:

[0016] Determine the array element spacing threshold according to the preset frequency;

[0017] According to the array element spacing threshold and the spacing between adjacent array elements in the towed linear array sonar, each target array element in the towed linear array sonar is determined.

[0018] Optionally, determining each target array element in the towed linear array sonar according to an array element spacing threshold and a spacing between adjacent array elements in the towed linear array sonar specifically includes:

[0019] For each array element in the towed linear array sonar, if the distance between the array element and an adjacent array element in a preset direction is less than the array element spacing threshold, the array element is used as a target array element.

[0020] Optionally, processing the signal information received by each target array element to generate a target beam pattern specifically includes:

[0021] According to the positional relationship between the array elements in the towed linear array sonar, a first coordinate system is established, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the first coordinate system are used to represent the position of each array element in the towed linear array sonar;

[0022] Determine a target output result obtained after Fourier transform of the signal received by each target array element;

[0023] For each directional angle, determine a target strength value of the signal for the directional angle according to the corresponding coordinates of each target array element on the horizontal axis in the first coordinate system, the preset frequency, and the target output result;

[0024] A target beam pattern is generated according to the target strength value of the signal at each directional angle.

[0025] Optionally, processing the signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern specifically includes:

[0026] According to the positional relationship between the array elements in the towed linear array sonar, a second coordinate system is established, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the second coordinate system are used to represent the position of each array element in the towed linear array sonar;

[0027] Determine a basic output result obtained after Fourier transform of the signal received by each array element in the towed linear array sonar;

[0028] For each directional angle, determine a basic strength value of the signal for the directional angle according to the corresponding coordinates of each array element in the towed linear array sonar on the horizontal axis in the second coordinate system, the preset frequency and the basic output result;

[0029] A basic beam pattern is generated according to the basic strength value of the signal at each directional angle.

[0030] Optionally, processing the signal information received by each target array element to generate a target beam pattern specifically includes:

[0031] Processing the signal information received by each target array element to generate an initial beam pattern;

[0032] The initial beam pattern is processed with high resolution to determine a target beam pattern.

[0033] Optionally, performing high-resolution processing on the initial beam pattern to determine a target beam pattern specifically includes:

[0034] According to the positional relationship between the array elements in the towed linear array sonar, a third coordinate system is established, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the third coordinate system are used to represent the position of each array element in the towed linear array sonar;

[0035] Determine the response strength of each target array element to the signal at each direction angle according to the corresponding coordinates of each target array element on the horizontal axis in the third coordinate system and the preset frequency;

[0036] A target beam pattern is determined according to the response strength and the initial beam pattern.

[0037] This specification provides a target detection device, comprising:

[0038] A determination module, used for determining each target array element in a towed linear array sonar, wherein each target array element refers to an array element in the towed linear array sonar for receiving a signal of a preset frequency, and the array elements in the towed linear array sonar are arranged in a linear manner;

[0039] a processing module, configured to process the signal information received by each target array element to generate a target beam diagram, and to process the signal information received by all array elements in the towed linear array sonar to generate a basic beam diagram, wherein the target beam diagram is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam diagram is used to characterize the intensity distribution of the signal received by all array elements in the towed linear array sonar in an omnidirectional angle;

[0040] An adjustment module, configured to adjust the basic beam pattern according to the target beam pattern to obtain a final beam pattern;

[0041] An execution module is used to perform target detection according to the final beam pattern.

[0042] This specification provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned target detection method is implemented.

[0043] This specification provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned target detection method when executing the program.

[0044] At least one of the above technical solutions adopted in this specification can achieve the following beneficial effects:

[0045] In the target detection method provided in this specification, each target array element in the towed linear array sonar is determined, and the signal information received by each target array element is processed to generate a target beam diagram, and the signal information received by all array elements in the towed linear array sonar is processed to generate a basic beam diagram. Then, according to the target beam diagram, the basic beam diagram is adjusted to obtain a final beam diagram, and target detection is performed according to the final beam diagram.

[0046] It can be seen from the above method that in the target detection method provided in this specification, the basic beam pattern is adjusted according to the target beam pattern to obtain the final beam pattern. The final beam pattern obtained in this way is more accurate, and can more clearly reflect the intensity distribution of the signal in the omnidirectional angle, especially for higher frequency signals, which can be more effectively detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of this specification and constitute a part of this specification. The illustrative embodiments and descriptions of this specification are used to explain this specification and do not constitute an improper limitation on this specification. In the drawings:

[0048] Figure 1 A schematic diagram of a target detection method provided in this specification;

[0049] Figure 2 A schematic diagram of a method for obtaining a final beam pattern provided in this specification;

[0050] Figure 3 A schematic diagram of a target detection device provided in this specification;

[0051] Figure 4 A method provided in this specification corresponding to Figure 1 Schematic diagram of electronic equipment. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of this specification more clear, the technical solutions of this specification will be clearly and completely described below in combination with the specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.

[0053] In the application of passive towed linear array sonar, when the towed linear array sonar works omnidirectionally, in order to avoid the direction estimation error caused by the grating lobe effect, the distance between adjacent array elements in the linear array must meet the condition of being less than half the wavelength of the sound wave.

[0054] For low-frequency signals, there are more available array elements in the towed linear array sonar that satisfy the requirement that the distance between adjacent array elements is less than half a wavelength, while for high-frequency signals, there are fewer available array elements in the towed linear array sonar that satisfy the requirement that the distance between adjacent array elements is less than half a wavelength. Therefore, for high-frequency signals, the existing technology cannot obtain an accurate beam pattern, and thus cannot perform effective detection.

[0055] Based on this, this specification provides a target detection method, which determines each target array element in a towed linear array sonar, processes the signal information received by each target array element, generates a target beam diagram, and processes the signal information received by all array elements in the towed linear array sonar to generate a basic beam diagram. Then, according to the target beam diagram, the basic beam diagram is adjusted to obtain a final beam diagram, and target detection is performed according to the final beam diagram.

[0056] The final beam pattern obtained in this way is more accurate, and can more clearly reflect the intensity distribution of the signal in the omnidirectional angle, especially for more effective detection of higher frequency signals.

[0057] The technical solutions provided by the embodiments of this specification are described in detail below in conjunction with the accompanying drawings.

[0058] Figure 1 A flow chart of a target detection method provided in this specification includes the following steps:

[0059] S101: Determine each target array element in the towed linear array sonar.

[0060] In this specification, the execution entity used to implement a target detection method can be a terminal device such as a laptop computer, a tablet computer, or of course, a server. For the sake of ease of description, this specification only takes the server as an execution entity as an example to illustrate a target detection method provided in this specification.

[0061] The server determines each target array element in the towed linear array sonar, wherein a number of array elements are arranged linearly in the towed linear array, and the distances between these array elements can be from large to small or from small to large. Here, from large to small and from small to large do not mean a simple gradual increase or decrease, but means that the distances between adjacent array elements in a certain continuous section of array elements can be the same, but the distances between adjacent array elements in the next continuous section of array elements in a preset direction can be greater than or less than the distances between adjacent array elements in the previous continuous section of array elements.

[0062] For example, there are 12 array elements in a towed linear array, where the distance between adjacent array elements in the 1st to 4th array elements is 0.1, the distance between adjacent array elements in the 4th to 8th array elements is 0.15, and the distance between adjacent array elements in the 8th to 12th array elements is 0.2. Each target array element refers to an array element in the towed linear array sonar that can be used to receive a signal of a preset frequency, that is, when the frequency corresponding to the signal is the preset frequency, the beam pattern generated after receiving the signal through each target array element will not produce a grating lobe effect.

[0063] For a preset frequency, a beam pattern is generated based on the signal information received by the towed linear array. If the generated beam pattern is to not produce a grating lobe effect, each target array element needs to satisfy the condition that the distance between adjacent array elements is less than the array element spacing threshold. Specifically, the array element spacing threshold can be expressed by the formula:

[0064]

[0065] Among them, d max represents the element spacing threshold; c represents the propagation speed of sound waves in water when the signal is sound waves, which is generally 1540m / s; f represents the preset frequency; θ represents the observation range of the towed linear array. If you want the beam pattern generated by the towed linear array to not produce grating lobe effect during omnidirectional observation (θ can be 0-180 degrees during omnidirectional observation), you need to make sinθ take the maximum value, that is, when θ = 90 degrees and sinθ = 1,

[0066] Further, the server determines the preset frequency, that is, the frequency of the signal for which the final beam pattern generated this time is specifically targeted. Then, the server can calculate the preset frequency and the above formula (that is, c=1540m / s), determine the array element spacing threshold.

[0067] In addition, the server can also obtain the wavelength corresponding to the preset frequency according to the preset frequency, and determine the array element spacing threshold through the wavelength. The specific process can be expressed by the formula:

[0068]

[0069] Wherein, c represents the propagation speed of sound waves in water when the signal is a sound wave, which is generally 1540 m / s; f represents the preset frequency; λ represents the wavelength corresponding to the preset frequency; d max Indicates the array element spacing threshold.

[0070] Furthermore, for each array element in the towed linear array sonar, if the distance between the array element and an adjacent array element in a preset direction is less than an array element spacing threshold, the server may use the array element as a target array element.

[0071] In order to explain more clearly how to determine each target array element, the server can establish a target coordinate system based on the positional relationship between the array elements in the towed linear array sonar, wherein the first array element in the towed linear array can be used as the origin of the horizontal axis in the target coordinate system, and the coordinates corresponding to each array element recorded on the horizontal axis in the target coordinate system are used to represent the position of each array element in the towed linear array sonar. For example, if there are M array elements in total, the coordinates corresponding to each array element recorded on the horizontal axis in the target coordinate system can be marked as x k , k = 0, 1, 2, ..., M-1, where x0 represents the coordinate of the first array element on the horizontal axis in the target coordinate system, x1 represents the coordinate of the second array element on the horizontal axis in the target coordinate system, and x k Represents the coordinate of the k+1th array element on the horizontal axis in the target coordinate system.

[0072] Then, for each array element, the server determines whether the array element can be used as the target array element according to the coordinates corresponding to the array element on the horizontal axis in the target coordinate system and the coordinates corresponding to the array element adjacent to the array element in the preset direction on the horizontal axis in the target coordinate system (the preset direction may refer to the direction of the horizontal axis in the target coordinate system), which can be specifically expressed by the formula:

[0073] s d [k] = x k+1 -x k

[0074] s d[k] <d max

[0075] Among them, s d [k] represents the distance between the kth array element and the k+1th array element, x k represents the coordinate of the kth array element on the horizontal axis in the target coordinate system, x k+1 represents the coordinate of the k+1th array element on the horizontal axis in the target coordinate system; d max Indicates the array element spacing threshold.

[0076] The server can determine whether the distance between the kth array element and the k+1th array element is less than the array element spacing threshold. If so, the kth array element is used as the target array element. Since all array elements in the dragging linear array are arranged in a way that the distance between adjacent array elements is from large to small or from small to large, the obtained k value is also continuous, and there is a maximum value of k, which is recorded as K max , the minimum value of k, denoted as K min , that is, in the drag line array, from the Kth min Element to Kth max The array elements are the determined target array elements.

[0077] S102: Processing the signal information received by each target array element to generate a target beam pattern, and processing the signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern.

[0078] The server processes the signal information received by each target array element to generate a target beam diagram, and processes the signal information received by all array elements in the towed linear array sonar to generate a basic beam diagram. The target beam diagram is used to characterize the intensity distribution of the signal received by each target array element in the omnidirectional angle, and the basic beam diagram is used to characterize the intensity distribution of the signal received by all array elements in the towed linear array sonar in the omnidirectional angle.

[0079] Specifically, the server can establish a first coordinate system according to the positional relationship between the array elements in the towed linear array sonar, wherein the first array element in the towed linear array can be used as the origin of the horizontal axis in the first coordinate system, and the coordinates corresponding to each array element recorded on the horizontal axis in the first coordinate system are used to represent the position of each array element in the towed linear array sonar. Then, the server determines the target output result obtained after the signal received by each target array element is Fourier transformed, and for each directional angle, the target intensity value of the signal for the directional angle is determined according to the corresponding coordinates of each target array element on the horizontal axis in the first coordinate system, the preset frequency, and the target output result. And a target beam pattern is generated according to the target intensity value of the signal at each directional angle.

[0080] In this specification, the process of the server generating the target beam pattern according to the signal information received by each target array element can be expressed by the formula:

[0081]

[0082] Where θ represents the direction angle; B sub (θ) represents the target beam pattern; x k is the coordinate of the horizontal axis of the kth array element in the first coordinate system; c represents the propagation speed of the sound wave in water when the signal is a sound wave, which is generally 1540 m / s; f represents the preset frequency; Represents the phase delay factor, which is used to compensate for the phase difference of signals from the same direction received by different array elements; X k [f] represents the output result obtained at the preset frequency after the signal received by the kth array element is Fourier transformed; K max Indicates the maximum value of k corresponding to each target array element; K min Indicates the minimum value of k corresponding to each target array element; the value of k in this formula is K min To K max .

[0083] At the same time, the server can establish a second coordinate system based on the positional relationship between the array elements in the towed linear array sonar, wherein the first array element in the towed linear array can be used as the origin of the horizontal axis in the second coordinate system, and the coordinates corresponding to each array element recorded on the horizontal axis in the second coordinate system are used to represent the position of each array element in the towed linear array sonar. Then, the server determines the basic output result obtained after Fourier transform of the signal received by each array element in the towed linear array sonar, and for each directional angle, determines the basic strength value of the signal for the directional angle according to the corresponding coordinates of each array element in the towed linear array sonar on the horizontal axis in the second coordinate system, the preset frequency, and the basic output result. And generate a basic beam pattern based on the basic strength value of the signal at each directional angle.

[0084] In this specification, the process of generating a basic beam pattern by the server according to the signal information received by all array elements in the towed linear array can be expressed as:

[0085]

[0086] Where θ represents the direction angle; B full (θ) represents the basic beam pattern; x k is the coordinate of the kth array element on the horizontal axis in the second coordinate system; c represents the propagation speed of the sound wave in water when the signal is a sound wave, which is generally 1540 m / s; f represents the preset frequency; Represents the phase delay factor, which is used to compensate for the phase difference of signals from the same direction received by different array elements; X k [f] represents the output result obtained at the preset frequency after the signal received by the kth array element is Fourier transformed; M represents a total of M array elements, and the value of k in the formula ranges from 0 to M-1.

[0087] It should be noted that in order to obtain a target beam diagram with higher resolution and to better adjust the basic beam diagram, the server can further process the target beam diagram. Specifically, the server can establish a third coordinate system based on the positional relationship between the array elements in the towed linear array sonar, wherein the first array element in the towed linear array can be used as the origin of the horizontal axis in the third coordinate system, and the coordinates corresponding to each array element recorded on the horizontal axis in the third coordinate system are used to represent the position of each array element in the towed linear array sonar.

[0088] Further, the server determines the response strength of each target array element to the signal at each direction angle according to the corresponding coordinates of each target array element on the horizontal axis in the third coordinate system and the preset frequency. Then, the server determines the target beam pattern according to the response strength and the initial beam pattern.

[0089] In this specification, the server determines the response strength of each target array element to the signal at each direction angle according to the coordinate of the horizontal axis of each target array element in the third coordinate system and the preset frequency. Here, the response strength of each target array element for each direction angle can be determined by a PSF function, and the PSF function can be expressed as:

[0090]

[0091] Among them, θ represents the direction angle; PSF(θ) represents the response strength of each target array element to the signal at each direction angle, that is, the function value of the PSF function represents the response strength of each target array element when the direction angle is θ. If the function value of the PSF function at a certain direction angle is large, it means that the gain of each target array element in this direction is high and the signal in this direction can be better detected; x k is the coordinate of the kth array element on the horizontal axis in the third coordinate system; c represents the propagation speed of the sound wave in water when the signal is a sound wave, which is generally 1540 m / s; f represents the preset frequency; K represents the phase delay factor, which is used to compensate for the phase difference of signals from the same direction received by different array elements; max Indicates the maximum value of k corresponding to each target array element; K min Indicates the minimum value of k corresponding to each target array element; the value of k in this formula is K min To K max .

[0092] Furthermore, the server determines the target beam pattern according to the response strength of each target array element to the signal at each direction angle and the initial beam pattern. Specifically, the server can use the PSF function to deconvolute the initial beam pattern, thereby reducing the main lobe width and side lobe level, and improving the performance of the towed linear array sonar. Among them, the main lobe refers to the direction with the greatest intensity when the signal is radiated or received, and the main lobe width refers to how wide this strongest directional area is. The narrower the main lobe width means the better the directivity. The side lobe level refers to the strength of the side lobe signal, which is usually the ratio between the main lobe signal strength and the side lobe signal strength. Reducing the side lobe level and weakening the side lobe signal strength can concentrate more energy on the main lobe.

[0093] That is to say, the server can use the response strength of each target array element to the signal at each direction angle to deconvolute the initial beam pattern. The deconvoluting process here can refer to one or more times, and its specific process can be expressed by the formula:

[0094]

[0095] in, represents the target beam pattern obtained after the nth unconvolution process, represents the target beam pattern obtained after the n+1th deconvolution process. When n=0, is the initial beam pattern, and PSF(θ) represents the response strength of each target array element to the signal at each directional angle. It should be noted that in the above formula, the target beam pattern and the PSF function can be represented in the form of a vector. For example, if the target beam pattern is used to represent the intensity distribution of the signal received by each target array element in the omnidirectional angle, then each element in the vector form of the target beam pattern can refer to the target intensity value of the received signal for each directional angle; if PSF(θ) is used to represent the response strength of each target array element to the signal at each directional angle, then each element in the vector form of the PSF function can refer to the magnitude of the response strength of each target array element to the signal at each directional angle.

[0096] In this manual, .* represents a dot multiplication operation, . / represents a dot division operation, Represents a convolution operation. Specifically, for two vectors of equal length, the dot product operation represents the multiplication of the corresponding elements in the two vectors. For example, for the vector [2,3,5] and the vector [6,2,1], the result of the dot product operation is also a vector, which is the vector [2*6,3*2,5*1], that is, [12,6,5]. For two vectors of equal length, the dot division operation represents the division of the corresponding elements in the two vectors. For example, for the vector [2,3,5] and the vector [6,2,1], the result of the dot division operation is also a vector, which is the vector [2 / 6,3 / 2,5 / 1], that is,

[0097] Convolution operations usually involve two vectors: an input vector and a kernel vector. The convolution process is to flip the kernel vector (in some cases, flipping may not be necessary), then translate it on the input vector, and multiply and sum it with the corresponding element of the input vector at each translation position. This process is repeated until the kernel vector covers all possible positions of the input vector.

[0098] For example, when performing a convolution operation on two vectors of equal length, a = [1, 2, 3], b = [1, 0, -1].

[0099] When the first element of vector b is aligned with the first element of vector a: 1×1+0×2+(-1)×3=1-3=-2;

[0100] Translate vector b so that the first element of vector b is aligned with the second element of vector a: 1×2+0×3+(-1)×1=2-1=1;

[0101] Translate vector b again, when the first element of vector b is aligned with the third element of vector a: 1×3+0×1+(-1)×2=3-2=1;

[0102] Therefore, the result of the convolution operation of vector a and vector b is a new vector c = [-2, 1, 1]. It should be noted that in the above example of convolution operation, in the process of translating b, the wrap-around processing method is used, that is, when the first element of vector b is aligned with the second element of vector a, the second element of vector b is aligned with the third element of vector a, and the third element of vector b is aligned with the first element of vector a. In practical applications, it is more common to use a filling processing method (such as zero filling, edge copy filling, etc.), that is, when the first element of vector b is aligned with the second element of vector a, the second element of vector b is aligned with the third element of vector a, and zero is added before the first element of vector b, so the value aligned with the first element of vector a is zero.

[0103] In this specification, the number of deconvolution processing may be 3 to 5 times. For example, if the number of deconvolution processing is 3 times, the target beam pattern obtained by the server after the third deconvolution processing is If the number of deconvolution processes is 5, the target beam pattern obtained by the server after the 5th deconvolution process is final, and Can be used It is represented as a target beam diagram after high-resolution processing.

[0104] In addition to the above-mentioned high-resolution processing method, this specification also provides a method in which the server can process the signal information received by each target array element through minimum variance distortionless response (MVDR). Among them, MVDR is an adaptive filtering technology used in signal processing, which plays an important role in beam pattern processing. The core goal of the MVDR method is to minimize the variance of noise or interference without distorting the target signal. Specifically, it achieves this goal by calculating weighting coefficients, which are determined by the covariance matrix of the received signal (i.e., the statistical characteristics of the signal). In this way, it can ensure that the target signal (such as a voice signal from a specific direction) is transmitted without distortion while maximizing the suppression of background noise. In the process of generating the target beam pattern, the MVDR method adjusts the weighting coefficients of each target array element so that the system has the desired response to the sound waves in a specific direction. This can not only enhance the signal from the target direction, but also suppress noise and interference in other directions. In short, the server can obtain a clear target beam pattern through MVDR, in which the signal strength in the target direction is significantly enhanced, while the signals in other directions are effectively suppressed.

[0105] In addition, in addition to the MVDR method mentioned in the above process, generating a target beam diagram under other criteria can also obtain a target beam diagram with higher resolution, such as the maximum signal-to-noise ratio criterion, the minimum mean square error criterion, the linear constrained minimum variance criterion, etc., as long as the method in this specification can be completed, no specific limitation is made here.

[0106] It should be noted that the first coordinate system, the second coordinate system, the third coordinate system and the target coordinate system mentioned in the above process can refer to exactly the same coordinate system or different coordinate systems. When these four coordinate systems refer to different coordinate systems, the server needs to first standardize these four coordinate systems to complete the task of generating target beam diagrams and basic beam diagrams. For example, for the same array element in a towed linear array sonar, the coordinates corresponding to the array element in these four coordinate systems can be integer multiples. In this way, the coordinates corresponding to the same array element in these four coordinate systems can be more conveniently and quickly converted to each other.

[0107] S103: According to the target beam pattern, the basic beam pattern is adjusted to obtain a final beam pattern.

[0108] The server adjusts the basic beam pattern according to the target beam pattern to obtain the final beam pattern. In other words, the server uses the target beam pattern to offset the errors in the basic beam pattern and strengthen the correct parts, thereby completing the adjustment of the basic beam pattern. For example, for each directional angle, the server can adjust the basic intensity value of the signal in the basic beam pattern for the directional angle by the target intensity value of the signal in the target beam pattern for the directional angle to obtain a more accurate final beam pattern.

[0109] Here, the process of adjusting the basic beam pattern by the target beam pattern can be specifically expressed by the formula:

[0110] B=B full (θ).*B sub (θ)

[0111] Where θ represents the direction angle; B represents the final beam pattern; B full (θ) represents the basic beam pattern; B sub (θ) represents the target beam pattern; .* represents the dot multiplication operation, that is, for each directional angle, the intensity value corresponding to the directional angle in the final beam pattern is equal to the basic intensity value corresponding to the directional angle in the basic beam pattern multiplied by the target intensity value corresponding to the directional angle in the target beam pattern. The server generates the final beam pattern according to the intensity value corresponding to each directional angle in the final beam pattern.

[0112] In the above process, the server can perform high-resolution processing on the target beam pattern in advance, and adjust the basic beam pattern according to the beam pattern after high-resolution processing to obtain the final beam pattern. The specific process can be expressed by the formula:

[0113]

[0114] Where θ represents the direction angle; B represents the final beam pattern; B full (θ) represents the basic beam pattern; represents the target beam pattern after high-resolution processing; .* represents the dot multiplication operation, that is, in this formula, for each directional angle, the intensity value corresponding to the directional angle in the final beam pattern is equal to the basic intensity value corresponding to the directional angle in the basic beam pattern multiplied by the target intensity value corresponding to the directional angle in the target beam pattern after high-resolution processing. The server generates the final beam pattern according to the intensity value corresponding to each directional angle in the final beam pattern.

[0115] S104: Perform target detection according to the final beam pattern.

[0116] The server performs target detection based on the final beam pattern. Target detection belongs to the field of underwater detection and imaging. The server can more accurately determine the location and nature of underwater target devices through the final beam pattern. The target devices here can refer to submarines, sunken ships, underwater obstacles, etc.

[0117] In order to explain the method in this specification more clearly, this specification provides a complete example to illustrate the above method, such as Figure 2 shown.

[0118] Figure 2 A schematic diagram of a method for obtaining a final beam pattern provided in this specification.

[0119] from Figure 2 It can be seen that the server obtains the signal information and preset frequency received by each array element in the towed linear array sonar, and determines each target array element from all array elements. Then, the server generates an initial beam diagram based on the signal information received by each target array element, and further determines the response strength of each target array element to the signal at each direction angle based on the determined target array elements, and then obtains the target beam diagram based on the initial beam diagram and the response strength of each target array element to the signal at each direction angle. At the same time, the server can generate a basic beam diagram based on the signal information received by all array elements in the towed linear array sonar. Furthermore, the server obtains the final beam diagram based on the target beam diagram and the basic beam diagram.

[0120] In this specification, the basic beam pattern is adjusted through the target beam pattern, and the final beam pattern obtained can more accurately characterize the intensity distribution corresponding to the received signal, thereby improving the accuracy of towed linear array sonar detection, especially for higher frequency signals, which can be more effectively detected.

[0121] In this method, before adjusting the basic beam pattern through the target beam pattern, the target beam pattern can also be processed with high resolution, that is, the signal from the target direction is enhanced and the noise and interference from other directions are suppressed to obtain a more accurate target beam pattern.

[0122] In addition, when determining each target array element, the array element spacing threshold can be obtained according to the preset frequency, so as to determine which array elements can be used as target array elements according to the array element spacing threshold. In this way, each target array element determined is more in line with the requirements of the actual scene, thereby generating a more accurate target beam diagram.

[0123] The above are one or more target detection methods of this specification. Based on the same idea, this specification also provides a corresponding target detection device, such as Figure 3 shown.

[0124] Figure 3 A schematic diagram of a target detection device provided in this specification includes:

[0125] A determination module 301 is used to determine each target array element in a towed linear array sonar, wherein each target array element refers to an array element in the towed linear array sonar for receiving a signal of a preset frequency, and the array elements in the towed linear array sonar are arranged in a linear manner;

[0126] The processing module 302 is used to process the signal information received by each target array element to generate a target beam diagram, and to process the signal information received by all array elements in the towed linear array sonar to generate a basic beam diagram, wherein the target beam diagram is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam diagram is used to characterize the intensity distribution of the signal received by all array elements in the towed linear array sonar in an omnidirectional angle;

[0127] An adjustment module 303, configured to adjust the basic beam pattern according to the target beam pattern to obtain a final beam pattern;

[0128] The execution module 304 is configured to perform target detection according to the final beam pattern.

[0129] Optionally, the determination module 301 is specifically configured to determine an array element spacing threshold according to a preset frequency; and determine each target array element in the towed linear array sonar according to the array element spacing threshold and a spacing between adjacent array elements in the towed linear array sonar.

[0130] Optionally, the determination module 301 is specifically configured to, for each array element in the towed linear array sonar, if the distance between the array element and an adjacent array element in a preset direction is less than the array element spacing threshold, take the array element as a target array element.

[0131] Optionally, the processing module 302 is specifically used to establish a first coordinate system according to the positional relationship between the array elements in the towed linear array sonar, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the first coordinate system are used to represent the position of each array element in the towed linear array sonar; determine a target output result obtained after Fourier transform of the signal received by each target array element; for each directional angle, determine a target strength value of the signal for the directional angle according to the coordinates corresponding to the target array elements on the horizontal axis in the first coordinate system, the preset frequency and the target output result; and generate a target beam pattern according to the target strength value of the signal at each directional angle.

[0132] Optionally, the processing module 302 is specifically used to establish a second coordinate system according to the positional relationship between the array elements in the towed linear array sonar, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the second coordinate system are used to represent the position of each array element in the towed linear array sonar; determine a basic output result obtained after Fourier transform of the signal received by each array element in the towed linear array sonar; for each directional angle, determine a basic strength value of the signal for the directional angle according to the coordinates corresponding to each array element in the towed linear array sonar on the horizontal axis in the second coordinate system, the preset frequency and the basic output result; and generate a basic beam pattern according to the basic strength value of the signal at each directional angle.

[0133] Optionally, the processing module 302 is specifically configured to process the signal information received by each target array element to generate an initial beam pattern; and perform high-resolution processing on the initial beam pattern to determine a target beam pattern.

[0134] Optionally, the processing module 302 is specifically used to establish a third coordinate system according to the positional relationship between the array elements in the towed linear array sonar, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the third coordinate system are used to represent the position of each array element in the towed linear array sonar; determine the response strength of each target array element to the signal at each direction angle according to the coordinates corresponding to the target array elements on the horizontal axis in the third coordinate system and the preset frequency; and determine the target beam pattern according to the response strength and the initial beam pattern.

[0135] This specification also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 A target detection method is provided.

[0136] This manual also provides Figure 4 The one shown corresponds to Figure 1 A schematic diagram of the electronic device. Figure 4 As mentioned above, at the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 Of course, in addition to the software implementation, this specification does not exclude other implementations, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0137] For the improvement of a technology, it can be clearly distinguished whether it is a hardware improvement (for example, improvement of the circuit structure of diodes, transistors, switches, etc.) or a software improvement (improvement of the method flow). However, with the development of technology, many improvements of the method flow today can be regarded as direct improvements of the hardware circuit structure. Designers almost always obtain the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow cannot be implemented with a hardware entity module. For example, a programmable logic device (PLD) (such as a field programmable gate array (FPGA)) is such an integrated circuit whose logical function is determined by the user's programming of the device. Designers can "integrate" a digital system on a PLD by programming themselves, without having to ask chip manufacturers to design and make dedicated integrated circuit chips. Moreover, nowadays, instead of manually making integrated circuit chips, this kind of programming is mostly implemented by "logic compiler" software, which is similar to the software compiler used when developing and writing programs, and the original code before compilation must also be written in a specific programming language, which is called hardware description language (HDL). There is not only one HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should also know that it is only necessary to program the method flow slightly in the above-mentioned hardware description languages ​​and program it into the integrated circuit, and then it is easy to obtain the hardware circuit that implements the logic method flow.

[0138] The controller can be implemented in any appropriate manner, for example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing a computer-readable program code (such as software or firmware) that can be executed by the (micro)processor, a logic gate, a switch, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in a purely computer-readable program code manner, the controller can be implemented in the form of a logic gate, a switch, an application-specific integrated circuit, a programmable logic controller, and an embedded microcontroller by logically programming the method steps. Therefore, this controller can be considered as a hardware component, and the devices included therein for implementing various functions can also be regarded as structures within the hardware component. Or even, the devices for implementing various functions can be regarded as both software modules for implementing the method and structures within the hardware component.

[0139] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0140] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0141] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems, or computer program products. Therefore, this specification may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0142] This specification is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of this specification. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0143] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0144] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0145] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0146] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0147] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0148] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0149] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems or computer program products. Therefore, this specification may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0150] This specification may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. This specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0151] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0152] The above description is only an embodiment of the present specification and is not intended to limit the present specification. For those skilled in the art, the present specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present specification shall be included in the scope of the claims of the present specification.

Claims

1. A target detection method, characterized in that: include: Determining target array elements in a towed linear array sonar, wherein the target array elements refer to array elements in the towed linear array sonar for receiving signals of a preset frequency, and the array elements in the towed linear array sonar are arranged in a linear manner; Processing the signal information received by each target array element to generate a target beam diagram, and processing the signal information received by all array elements in the towed linear array sonar to generate a basic beam diagram, wherein the target beam diagram is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam diagram is used to characterize the intensity distribution of the signal received by all array elements in the towed linear array sonar in an omnidirectional angle; According to the target beam pattern, the basic beam pattern is adjusted to obtain a final beam pattern; Target detection is performed according to the final beam pattern.

2. The method according to claim 1, characterized in that Determine the target array elements in the towed linear array sonar, including: Determine the array element spacing threshold according to the preset frequency; According to the array element spacing threshold and the spacing between adjacent array elements in the towed linear array sonar, each target array element in the towed linear array sonar is determined.

3. The method according to claim 2, characterized in that Determining target array elements in the towed linear array sonar according to an array element spacing threshold and a spacing between adjacent array elements in the towed linear array sonar specifically includes: For each array element in the towed linear array sonar, if the distance between the array element and an adjacent array element in a preset direction is less than the array element spacing threshold, the array element is used as a target array element.

4. The method according to claim 1, characterized in that Processing the signal information received by each target array element to generate a target beam pattern specifically includes: According to the positional relationship between the array elements in the towed linear array sonar, a first coordinate system is established, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the first coordinate system are used to represent the position of each array element in the towed linear array sonar; Determine a target output result obtained after Fourier transform of the signal received by each target array element; For each directional angle, determine a target strength value of the signal for the directional angle according to the corresponding coordinates of each target array element on the horizontal axis in the first coordinate system, the preset frequency, and the target output result; A target beam pattern is generated according to the target strength value of the signal at each directional angle.

5. The method according to claim 1, characterized in that The signal information received by all array elements of the towed linear array sonar is processed to generate a basic beam pattern, specifically including: According to the positional relationship between the array elements in the towed linear array sonar, a second coordinate system is established, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the second coordinate system are used to represent the position of each array element in the towed linear array sonar; Determine a basic output result obtained after Fourier transform of the signal received by each array element in the towed linear array sonar; For each directional angle, determine a basic strength value of the signal for the directional angle according to the corresponding coordinates of each array element in the towed linear array sonar on the horizontal axis in the second coordinate system, the preset frequency and the basic output result; A basic beam pattern is generated according to the basic strength value of the signal at each directional angle.

6. The method according to claim 1, characterized in that Processing the signal information received by each target array element to generate a target beam pattern specifically includes: Processing the signal information received by each target array element to generate an initial beam pattern; The initial beam pattern is processed with high resolution to determine a target beam pattern.

7. The method according to claim 6, characterized in that The initial beam pattern is processed with high resolution to determine a target beam pattern, specifically comprising: According to the positional relationship between the array elements in the towed linear array sonar, a third coordinate system is established, wherein the coordinates corresponding to each array element recorded on the horizontal axis in the third coordinate system are used to represent the position of each array element in the towed linear array sonar; Determine the response strength of each target array element to the signal at each direction angle according to the corresponding coordinates of each target array element on the horizontal axis in the third coordinate system and the preset frequency; A target beam pattern is determined according to the response strength and the initial beam pattern.

8. A target detection device, characterized in that: include: A determination module, used for determining each target array element in a towed linear array sonar, wherein each target array element refers to an array element in the towed linear array sonar for receiving a signal of a preset frequency, and the array elements in the towed linear array sonar are arranged in a linear manner; a processing module, configured to process the signal information received by each target array element to generate a target beam diagram, and to process the signal information received by all array elements in the towed linear array sonar to generate a basic beam diagram, wherein the target beam diagram is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam diagram is used to characterize the intensity distribution of the signal received by all array elements in the towed linear array sonar in an omnidirectional angle; An adjustment module, configured to adjust the basic beam pattern according to the target beam pattern to obtain a final beam pattern; An execution module is used to perform target detection according to the final beam pattern.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

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