Target detection method, device, storage medium and electronic equipment

Abstract

This specification discloses a target detection method, apparatus, storage medium, and electronic device. The method includes: identifying each target element in a towed linear array sonar, processing the signal information received by each target element to generate a target beam pattern, and processing the signal information received by all elements in the towed linear array sonar to generate a basic beam pattern. The basic beam pattern is then adjusted based on the target beam pattern to obtain a final beam pattern, and target detection is performed based on the final beam pattern.

Description

Technical Field

[0001] This specification 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 can be divided into active and passive types. Active sonar transmits sound waves, which are reflected by the target device. The receiver then analyzes and compares the echoes to determine the target device's location and distance. Passive sonar does not transmit sound waves, but instead detects the target device by receiving the sounds of its propellers or other mechanical operations.

[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 a towed linear array sonar covers multiple octaves. To avoid directional errors caused by the grating lobe effect, the distance between adjacent elements in the array must be less than half the wavelength of the sound wave when the towed linear array sonar operates omnidirectionally. Therefore, a towed linear array sonar is typically composed of several subarrays, each with a different spacing between elements. Each subarray corresponds to a specific octave within the towed linear array sonar's operating frequency band. The grating lobe effect refers to the phenomenon in which, in addition to the main lobe (the beam in the direction of maximum radiation or reception), stronger radiation or reception beams are formed in other directions during the radiation or reception process of a linear array or ultrasonic probe. These additional beams are called grating lobes. Simply put, when a beam pattern is generated from the signal received by a towed linear array, a signal appears in the direction of a 30-degree angle. Due to the grating lobe effect, a signal may also appear in the direction of a 60-degree angle, making it impossible 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, where the target array elements are 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 pattern, and processing the signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern, wherein the target beam pattern is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam pattern 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] Adjusting the basic beam pattern according to the target beam pattern 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] The target array elements in the towed linear array sonar are determined according to the array element spacing threshold and the spacing between adjacent array elements in the towed linear array sonar.

[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 regarded 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] Establishing a first coordinate system based on 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 of 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 based on the target strength value of the signal at each direction angle.

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

[0026] Establishing a second coordinate system based on 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 of 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 by Fourier transforming a signal received by each array element in the towed linear array sonar;

[0028] For each directional angle, determining a basic signal strength value for the directional angle based on 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 direction 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] Establishing a third coordinate system based on 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 of the third coordinate system are used to represent the position of each array element in the towed linear array sonar;

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

[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, configured to determine target array elements in a towed linear array sonar, wherein the target array elements are array elements in the towed linear array sonar configured to receive signals of a preset frequency, wherein 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 pattern, and to process the signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern, wherein the target beam pattern is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam pattern 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 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 herein, each target element in a towed linear array sonar is identified and the signal information received by each target element is processed to generate a target beam pattern. Furthermore, the signal information received by all elements in the towed linear array sonar is processed to generate a basic beam pattern. The basic beam pattern is then adjusted based on the target beam pattern to obtain a final beam pattern, and target detection is performed based on the final beam pattern.

[0046] As can be seen from the above method, 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. This method produces a more accurate final beam pattern, which can more clearly reflect the intensity distribution of the signal in all directions, especially for more effective detection of higher-frequency signals. 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 exemplary embodiments and descriptions of this specification are used to explain this specification and do not constitute an improper limitation of this specification. In the drawings:

[0048] Figure 1 A flowchart 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 This specification provides a corresponding Figure 1 Schematic diagram of electronic equipment. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of this specification more clear, the following will clearly and completely describe the technical solutions of this specification in conjunction with the specific embodiments of this specification and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without making any creative efforts 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 direction estimation errors caused by grating lobe effects, 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, a towed linear array sonar has more available elements that meet the requirement of keeping the distance between adjacent elements less than half a wavelength. However, for high-frequency signals, this requirement is limited. Therefore, existing technologies cannot generate accurate beam patterns for high-frequency signals, and thus cannot effectively detect them.

[0055] Based on this, this specification provides a target detection method that identifies each target element in a towed linear array sonar, processes the signal information received by each target element to generate a target beam pattern, and processes the signal information received by all elements in the towed linear array sonar to generate a basic beam pattern. The basic beam pattern is then adjusted based on the target beam pattern to obtain a final beam pattern, and target detection is performed based on the final beam pattern.

[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 with reference to the accompanying drawings.

[0058] Figure 1 This is a flow chart of a target detection method provided in this specification, which 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 the 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 plurality 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, a towed linear array has 12 elements, where the distance between adjacent elements 1-4 is 0.1, the distance between adjacent elements 4-8 is 0.15, and the distance between adjacent elements 8-12 is 0.2. Each target element refers to an element in the towed linear array sonar that can receive signals at a preset frequency. In other words, when the frequency corresponding to the signal is the preset frequency, the beam pattern generated by receiving the signal through each target element will not produce grating lobe effects.

[0063] For a preset frequency, based on the signal information received by the towed linear array, a beam pattern is generated. To prevent grating lobe effects, the distance between each target element and its adjacent elements must be less than the element spacing threshold. Specifically, the element spacing threshold can be expressed as:

[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 1540 m / 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 effects during omnidirectional observation (θ can be 0-180 degrees during omnidirectional observation), you need to maximize sinθ, that is, when θ = 90 degrees and sinθ = 1,

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

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

[0071] In order to more clearly explain 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. The first array element in the towed linear array can be used as the origin of the horizontal axis of the target coordinate system. The coordinates corresponding to each array element recorded on the horizontal axis of 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 of 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 Indicates 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 based on the coordinate corresponding to the array element on the horizontal axis in the target coordinate system and the coordinate corresponding to the array element adjacent to it 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). The specific formula can be expressed as follows:

[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 Indicates 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 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 drag 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 pattern, and also processes the signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern. The target beam pattern is used to represent the intensity distribution of the signal received by each target array element in the omnidirectional angle, while the basic beam pattern is used to represent 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 based on the positional relationship between the array elements in the towed linear array sonar. The first array element in the towed linear array can be used as the origin of the horizontal axis of the first coordinate system. The coordinates corresponding to each array element recorded on the horizontal axis of the first coordinate system are used to represent the position of each array element in the towed linear array sonar. The server then determines the target output result obtained by Fourier transforming the signals received by each target array element. For each directional angle, the server determines the target strength value of the signal for that directional angle based on the coordinates corresponding to each target array element on the horizontal axis of the first coordinate system, the preset frequency, and the target output result. A target beam pattern is then generated based on the target strength value of the signal for each directional angle.

[0080] In this specification, the process of the server generating the target beam pattern based on the signal information received by each target array element can be expressed as follows:

[0081]

[0082] Where θ represents the direction angle; B sub (θ) represents the target beam pattern; x k is the coordinate of the kth array element on the horizontal axis 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 k-th 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. The first array element in the towed linear array can be used as the origin of the horizontal axis of the second coordinate system. The coordinates corresponding to each array element recorded on the horizontal axis of the second coordinate system represent the position of each array element in the towed linear array sonar. The server then determines the basic output results obtained by Fourier transforming the signals received by each array element in the towed linear array sonar. For each directional angle, the server determines the basic signal strength value for that directional angle based on the corresponding coordinates of each array element in the towed linear array sonar on the horizontal axis of the second coordinate system, the preset frequency, and the basic output results. A basic beam pattern is then generated based on the basic signal strength values ​​for each directional angle.

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

[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 k-th array element is Fourier transformed; M represents the total number of M array elements, and the value of k in this formula ranges from 0 to M-1.

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

[0088] Furthermore, the server determines the response strength of each target element to the signal at each direction angle based on the corresponding coordinate of each target element on the horizontal axis in the third coordinate system and the preset frequency. The server then determines the target beam pattern based on 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 based on 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, which 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 to say, 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 that direction is high and it can better detect the signal in that direction; 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 based on the response strength of each target array element to the signal at various directional angles and the initial beam pattern. Specifically, the server can use the PSF function to deconvolute the initial beam pattern, thereby reducing the mainlobe width and sidelobe level, and improving the performance of the towed linear array sonar. Among them, the mainlobe refers to the direction in which the signal is radiated or received with the greatest intensity, and the mainlobe width refers to how wide this strongest directional area is. The narrower the mainlobe width, the better the directivity. The sidelobe level refers to the strength of the sidelobe signal, which is usually the ratio between the mainlobe signal strength and the sidelobe signal strength. Reducing the sidelobe level and weakening the sidelobe signal strength can concentrate more energy on the mainlobe.

[0093] In other words, the server can use the response strength of each target array element to the signal at various angles to deconvolve the initial beam pattern. The deconvolution process here can refer to one or more times. The specific process can be expressed as follows:

[0094]

[0095] in, represents the target beam pattern obtained after the nth deconvolution 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 PSF function can be represented in the form of vectors. 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 the 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 typically involve two vectors: an input vector and a kernel vector. The convolution process involves flipping the kernel vector (which may not be necessary in some cases), then translating it across the input vector and multiplying and summing the kernel vectors at each translated position with the corresponding element of the input vector. This process is repeated until the kernel vector covers all possible positions in the input vector.

[0098] For example, when performing convolution on two vectors of equal length, a = [1, 2, 3] and 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] Shift vector b again, so that 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 the convolution operation, the process of translating b is a wrap-around processing method, 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 padding processing method (such as zero padding, edge copy padding, 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 zeros are added before the first element of vector b. Therefore, the value aligned with the first element of vector a is zero.

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

[0104] In addition to the high-resolution processing method described above, this specification also provides a method by which the server can process the signal information received by each target array element through minimum variance distortionless response (MVDR). MVDR is an adaptive filtering technology used in signal processing and 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, the target signal (such as a voice signal from a specific direction) can be 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 sound waves in a specific direction. This not only enhances the signal from the target direction, but also suppresses noise and interference in other directions. In summary, 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, second coordinate system, third coordinate system, and target coordinate system mentioned in the above process can refer to 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 the target beam pattern and the basic beam pattern. For example, for the same array element in a towed linear array sonar, the coordinates corresponding to the 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 converted to each other more conveniently and quickly.

[0107] S103: Adjust the basic beam pattern according to the target beam pattern to obtain a final beam pattern.

[0108] The server adjusts the base beam pattern based on the target beam pattern to produce the final beam pattern. In other words, the server uses the target beam pattern to offset errors in the base beam pattern and strengthen accurate portions, thereby completing the adjustment of the base beam pattern. For example, for each directional angle, the server can use the target strength value of the signal for that directional angle in the target beam pattern to adjust the base strength value of the signal for that directional angle in the base beam pattern to produce a more accurate final beam pattern.

[0109] Here, the process of adjusting the basic beam pattern through 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; * denotes a dot product. This means that for each directional angle, the intensity value corresponding to that directional angle in the final beam pattern is equal to the base intensity value corresponding to that directional angle in the base beam pattern multiplied by the target intensity value corresponding to that directional angle in the target beam pattern. The server generates the final beam pattern based on 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 high-resolution processed beam pattern 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; The * represents the target beam pattern after high-resolution processing. The * denotes a dot product operation. In other words, in this formula, for each directional angle, the intensity value corresponding to that directional angle in the final beam pattern is equal to the base intensity value corresponding to that directional angle in the base beam pattern multiplied by the target intensity value corresponding to that directional angle in the high-resolution target beam pattern. The server generates the final beam pattern based on 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 then performs target detection based on the final beam pattern. This falls within the realm of underwater detection and imaging, allowing the server to more accurately determine the location and nature of underwater target devices, such as submarines, sunken ships, and underwater obstacles.

[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 This is a schematic diagram of a method for obtaining a final beam pattern provided in this specification.

[0119] from Figure 2 As can be seen, the server obtains the signal information and preset frequency received by each element in the towed linear array sonar and identifies the target elements from all elements. The server then generates an initial beam pattern based on the signal information received by each target element. Based on the identified target elements, the server further determines the response strength of each target element to the signal at various directions and angles. Based on the initial beam pattern and the response strength of each target element to the signal at various directions and angles, the target beam pattern is then obtained. Simultaneously, the server generates a basic beam pattern based on the signal information received by all elements in the towed linear array sonar. Furthermore, the server generates a final beam pattern based on the target beam pattern and the basic beam pattern.

[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 more effective detection of higher frequency signals.

[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] Furthermore, when determining target elements, an element spacing threshold can be first determined based on a preset frequency. This threshold can then be used to determine which elements are target elements. This ensures that the target elements determined are more consistent with actual scenario requirements, thereby generating a more accurate target beam pattern.

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

[0124] Figure 3 This is a schematic diagram of a target detection device provided in this specification, including:

[0125] a determination module 301 for determining target array elements in a towed linear array sonar, wherein the target array elements are 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;

[0126] a processing module 302 configured to process the signal information received by each target array element to generate a target beam pattern, and to process the signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern, wherein the target beam pattern is used to represent the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam pattern is used to represent 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 is 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 determining module 301 is specifically configured to determine an array element spacing threshold according to a preset frequency; and determine target array elements 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 determining module 301 is specifically configured to, for each array element in the towed linear array sonar, determine the array element as a target array element if the distance between the array element and an adjacent array element in a preset direction is less than the array element spacing threshold.

[0131] Optionally, the processing module 302 is specifically configured to establish a first coordinate system based on a positional relationship between array elements in the towed linear array sonar, wherein the coordinates corresponding to each array element recorded on the horizontal axis of 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 signals received by each target array element; determine, for each directional angle, a target strength value of the signal for the directional angle based on 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 based on the target strength value of the signal for each directional angle.

[0132] Optionally, the processing module 302 is specifically configured to establish a second coordinate system based on a positional relationship between array elements in the towed linear array sonar, wherein the coordinates corresponding to each array element recorded on the horizontal axis of 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 a signal received by each array element in the towed linear array sonar; determine, for each directional angle, a basic strength value of the signal for the directional angle based on 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 based on the basic strength value of the signal for 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 configured to establish a third coordinate system based on a positional relationship between array elements in the towed linear array sonar, wherein the coordinates corresponding to each array element recorded on the horizontal axis of 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 based on 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 based on the response strength and the initial beam pattern.

[0135] This specification also provides a computer-readable storage medium, which stores a computer program that 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 Schematic diagram of the electronic equipment. 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 software implementation, this specification does not exclude other implementation methods, 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] Improvements to a technology can be clearly distinguished as either hardware improvements (for example, improvements to circuit structures such as diodes, transistors, and switches) or software improvements (improvements to process flows). However, with technological advancements, many process flow improvements today can now be considered direct improvements to hardware circuit structures. Designers almost always program the improved process flow into the hardware circuit to obtain the corresponding hardware circuit structure. Therefore, it cannot be said that a process flow improvement cannot be implemented using a hardware module. For example, a programmable logic device (PLD), such as a field programmable gate array (FPGA), is an integrated circuit whose logical function is determined by user programming. Designers can "integrate" a digital system on a PLD by programming it themselves, without having to hire a chip manufacturer to design and manufacture a dedicated integrated circuit chip. Moreover, nowadays, instead of manually manufacturing integrated circuit chips, this programming is mostly done using "logic compiler" software. This is similar to the software compiler used when developing programs. Before compilation, the original code must also be written in a specific programming language, called a hardware description language (HDL). There is not just one HDL, but many, 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 will also understand that by simply programming the method flow in one of these hardware description languages ​​and then programming it into an integrated circuit, a hardware circuit that implements the logic method flow can be easily obtained.

[0138] The controller can be implemented in any suitable manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. 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 will also know that in addition to implementing the controller in a purely computer-readable program code format, the controller can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a controller can be considered a hardware component, and the devices included therein for implementing various functions can also be considered as structures within the hardware component. Or even, the devices for implementing various functions can be considered as both software modules that implement 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 having 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 smartphone, 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 devices are described as being divided into 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. Furthermore, 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 magnetic disk storage, CD-ROM, optical storage, etc.) containing 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 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 that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The 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 operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

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

[0146] 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. Memory is an example of a computer-readable medium.

[0147] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The 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 disc read-only memory (CD-ROM), digital versatile disc (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 transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0148] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0149] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems, or computer program products. Thus, this specification may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, 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 magnetic 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, such as program modules, executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and the like 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 communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media, including storage devices.

[0151] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0152] The foregoing is merely an example of the present invention and is not intended to limit the present invention. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A target detection method, characterized in that: include: Determining target array elements in a towed linear array sonar, where the target array elements are 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 pattern, and processing the signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern, wherein the target beam pattern is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam pattern 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; Adjusting the basic beam pattern according to the target beam pattern to obtain a final beam pattern; Target detection is performed according to the final beam pattern.

2. The method according to claim 1, wherein Identify the target elements in the towed linear array sonar, including: Determine the array element spacing threshold according to the preset frequency; The target array elements in the towed linear array sonar are determined according to the array element spacing threshold and the spacing between adjacent array elements in the towed linear array sonar.

3. The method according to claim 2, wherein 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 regarded as a target array element.

4. The method according to claim 1, wherein Processing the signal information received by each target array element to generate a target beam pattern specifically includes: Establishing a first coordinate system based on 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 of 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 based on the target strength value of the signal at each direction angle.

5. The method according to claim 1, wherein Processing the signal information received by all array elements of the towed linear array sonar to generate a basic beam pattern specifically includes: Establishing a second coordinate system based on 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 of 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 by Fourier transforming a signal received by each array element in the towed linear array sonar; For each directional angle, determining a basic signal strength value for the directional angle based on 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 direction angle.

6. The method according to claim 1, wherein 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, wherein The initial beam pattern is processed with high resolution to determine a target beam pattern, specifically comprising: Establishing a third coordinate system based on 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 of the third coordinate system are used to represent the position of each array element in the towed linear array sonar; determining, according to the coordinates corresponding to the target array elements on the horizontal axis in the third coordinate system and the preset frequency, the response strength of each target array element to the signal at each direction angle; 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, configured to determine target array elements in a towed linear array sonar, wherein the target array elements are array elements in the towed linear array sonar configured to receive signals of a preset frequency, wherein 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 pattern, and to process the signal information received by all array elements in the towed linear array sonar to generate a basic beam pattern, wherein the target beam pattern is used to characterize the intensity distribution of the signal received by each target array element in an omnidirectional angle, and the basic beam pattern 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, wherein: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

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