Single-transmitting multi-receiving underwater metal small target electromagnetic induction detection method

Abstract

The invention relates to the technical field of underwater target detection, in particular to a single-transmitting multi-receiving underwater metal small target electromagnetic induction detection method, which comprises the following steps: planning a detection route below an underwater metal small target to be detected according to different operating distances and different intersection angles; a single-transmitting multi-receiving antenna system composed of a transmitting antenna and a plurality of receiving sensors is fixed on an underwater vehicle to form an underwater detection device; an underwater detection device is controlled to pass through the lower part of the underwater metal small target according to a detection route, a transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside, and a plurality of receiving sensors receive signals; performing data processing on the signals received by the receiving sensors to obtain electromagnetic scattering field information of the underwater metal small target, and performing visualization processing to obtain a target passing characteristic curve; and performing imaging operation to obtain a three-dimensional contour image of the underwater small metal target, thereby efficiently, accurately and reliably identifying the shape of the underwater small metal target.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of underwater target detection, and in particular to a single-transmitter-multiple-receiver electromagnetic induction detection method for small underwater metal targets. Background Art

[0002] In the field of underwater target detection technology, metal target detection is of paramount importance and forms the basis for applications such as shipwreck searches, underwater metal mineral exploration, and underwater metal facility monitoring. Currently, the most commonly used underwater metal target detection technologies rely on laser detection, acoustic detection, and high-frequency electromagnetic detection. Underwater laser detection uses laser beams to detect and measure underwater environments. Its basic principle is to emit laser pulses underwater and receive the reflected light signals, thereby detecting underwater targets. Underwater acoustic detection uses sonar to detect and measure underwater environments. Its basic principle is to emit sound waves underwater and receive the reflected echoes, thereby detecting underwater targets. Underwater high-frequency electromagnetic detection utilizes a powerful, artificially generated magnetic field to detect underwater targets and resources. This method uses high-frequency electromagnetic waves to detect underwater targets by analyzing their attenuation, reflection, and scattering in water.

[0003] However, when laser light propagates through seawater, particles in the seawater will cause it to scatter, and the backscattered light will interfere with the detector's reception and recognition of the target's reflected light, making it difficult for underwater laser detection to meet actual needs in terms of detection distance and accuracy. Underwater acoustic detection technology is greatly affected by environmental noise and the propagation medium, and its detection accuracy in deeper waters is limited. In addition, sound waves propagate relatively slowly in seawater, and for large-scale detection, it takes a long time to complete a detection, making it difficult to meet the needs of rapid and large-scale detection. Due to the high electrical conductivity of seawater, it will cause more serious signal attenuation, and the water depth and target size have a significant impact on the propagation of high-frequency electromagnetic waves, making it difficult to effectively detect small metal targets in deep water, especially for metal targets with regular shapes underwater. The detection performance and recognition rate of underwater high-frequency electromagnetic detection technology are less than ideal.

[0004] Underwater low-frequency electromagnetic detection technology, with its excellent seawater penetration and high sensitivity to metal targets, has become an important means of underwater metal target detection. However, the currently commonly used single-transmitter, single-receiver low-frequency electromagnetic detection method is inefficient and cannot fully and accurately obtain detailed information about metal targets. Summary of the Invention

[0005] In order to solve the above technical problems, the embodiments of the present application propose a single-transmitter, multiple-receiver electromagnetic induction detection method for underwater small metal targets, which aims to utilize the propagation characteristics of electromagnetic waves in water to detect small underwater metal targets, and synchronously collect signals through multiple receiving units, thereby improving the efficiency, accuracy, reliability, and target recognition ability of underwater small metal target detection.

[0006] To achieve the above objectives, an embodiment of the present application proposes a single-transmitter, multiple-receiver electromagnetic induction detection method for small underwater metal targets, which is implemented based on a single-transmitter, multiple-receiver antenna system consisting of a transmitting antenna and multiple receiving sensors. The method includes the following steps: determining the small underwater metal target to be detected, and planning a detection route below the small underwater metal target according to different effective distances and different intersection angles; fixing the single-transmitter, multiple-receiver antenna system to an underwater vehicle through a rigid connection to form an underwater detection device, in which the multiple receiving sensors form a receiving sensor array, the spacing between two adjacent receiving sensors is equal, and the vertical distance between the transmitting antenna and the receiving sensor array is fixed; Underwater operations are carried out, and the underwater detection device is controlled to pass under the underwater small metal target according to the detection route. The transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive signals. After the underwater operation is completed, data processing is performed on the signals received by each receiving sensor to obtain electromagnetic scattering field information of the underwater small metal target, and then the electromagnetic scattering field information is visualized, and finally a target passing characteristic curve is obtained from each receiving sensor. Imaging operations are performed based on the electromagnetic scattering field information corresponding to each receiving sensor and the target passing characteristic curve to obtain a three-dimensional contour image of the underwater small metal target, and thus the shape of the underwater small metal target is recognized based on the three-dimensional contour image of the underwater small metal target.

[0007] In order to achieve the above-mentioned purpose, the embodiment of the present application also proposes a single-transmitter, multiple-receiver underwater metal small target electromagnetic induction detection system, the system comprising: a detection route planning module, used to determine the underwater metal small target that needs to be detected, and plan the detection route under the underwater metal small target according to different effective distances and different intersection angles; an underwater detection device assembly module, used to fix the single-transmitter, multiple-receiver antenna system consisting of a transmitting antenna and multiple receiving sensors on an underwater vehicle through a rigid connection to form an underwater detection device, in which the multiple receiving sensors form a receiving sensor array, the spacing between two adjacent receiving sensors is equal, and the vertical distance between the transmitting antenna and the receiving sensor array is fixed; an underwater operation command module, used to control the process of underwater operation. In the process, the underwater detection device is controlled to pass under the underwater small metal target according to the detection route, the transmitting antenna is instructed to continuously radiate low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive signals; the target passing characteristic curve drawing module is used to process the signals received by each receiving sensor after completing the underwater operation, obtain the electromagnetic scattering field information of the underwater small metal target, and then visualize the electromagnetic scattering field information, and finally obtain a target passing characteristic curve from each receiving sensor; the three-dimensional contour imaging recognition module is used to perform imaging operations based on the electromagnetic scattering field information corresponding to each receiving sensor and the target passing characteristic curve, and obtain a three-dimensional contour image of the underwater small metal target, so as to recognize the shape of the underwater small metal target based on the three-dimensional contour image of the underwater small metal target.

[0008] In order to achieve the above-mentioned purpose, an embodiment of the present application also proposes an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the single-transmitter-multiple-receiver underwater metal small target electromagnetic induction detection method as described above.

[0009] In order to achieve the above-mentioned purpose, an embodiment of the present application also proposes a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement the above-mentioned single-transmitter and multiple-receiver electromagnetic induction detection method for underwater small metal targets.

[0010] The present application proposes a single-transmitter, multi-receiver electromagnetic induction detection method for underwater small metal targets. The method is based on a single-transmitter, multi-receiver antenna system consisting of a transmitting antenna and multiple receiving sensors. Compared with the traditional single-transmitter, single-receiver antenna system, the single-transmitter, multi-receiver antenna system can detect underwater small metal targets with smaller sizes and weaker electromagnetic signals, and can complete the detection of specific underwater areas in a shorter time, greatly shortening the detection cycle. It can well meet the needs of rapid detection in practical applications. By rigidly connecting such a single-transmitter, multi-receiver antenna system to an underwater vehicle, an underwater detection device with very strong detection sensitivity and detection resolution can be obtained. When formulating the detection route, different effective distances and different intersection angles are combined to ensure that the underwater detection device can detect underwater small metal targets from multiple angles and distances, thereby enhancing the accuracy of detection and subsequent identification. When conducting underwater operations, the transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive signals. After completing the underwater operations, the signals received by each receiving sensor are processed. The multi-angle signals collected by each receiving sensor contain rich spatial information of the underwater small metal targets. After processing, a three-dimensional contour image of the underwater small metal targets can be constructed. This imaging capability helps to more intuitively display the shape and structure of the underwater small metal targets, so that the characteristics and types of the underwater small metal targets can be more clearly identified, thereby greatly improving the accuracy and reliability of recognition.

[0011] Optionally, when planning the detection route, the setting range of different effective distances is 1m to 3m, and the setting range of different intersection angles is 0 degrees to 90 degrees; in the underwater detection device, the transmitting antenna is a magnetic dipole structure, and its operating frequency is set in the range of 100Hz to 30kHz, the spacing between two adjacent receiving sensors is set in the range of 0.1m to 0.5m, and the vertical distance between the transmitting antenna and the receiving sensor array is set in the range of 0.5m to 2m.

[0012] Optionally, when planning the detection route, different effective distances are set to 1m, 2m, and 3m, and different intersection angles are set to 0 degrees, 30 degrees, 45 degrees, 60 degrees, and 90 degrees. Based on the pairwise combinations of different effective distances and different intersection angles, 15 detection routes are planned in sequence.

[0013] Optionally, underwater operations are performed, and the underwater detection device is controlled to pass under the small underwater metal target according to the detection route, the transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive signals, including: setting three different operating frequencies for the transmitting antenna, namely 1kHz, 10kHz, and 30kHz; configuring 45 underwater operations based on the three different operating frequencies and 15 different detection routes; in each underwater operation, the underwater detection device is controlled to pass under the small underwater metal target according to the corresponding detection route, the transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world based on the corresponding operating frequency, and multiple receiving sensors receive signals.

[0014] Optionally, data processing is performed on the signals received by each receiving sensor to obtain electromagnetic scattering field information of the underwater small metal target, and then the electromagnetic scattering field information is visualized, and finally a target passage characteristic curve is obtained from each receiving sensor, including: filtering, adaptive cancellation and feature extraction are performed on the signals received by each receiving sensor in sequence to obtain electromagnetic scattering field information of the x component, y component and z component of the underwater small metal target; and the electromagnetic scattering field information of the x component, y component and z component of the underwater small metal target are respectively visualized by curve fitting, and finally the target passage characteristic curves of the x component, y component and z component, that is, the amplitude-frequency characteristic curves of the x component, y component and z component, are obtained from each receiving sensor.

[0015] Optionally, an imaging operation is performed based on the electromagnetic scattering field information corresponding to each receiving sensor and the target passing characteristic curve to obtain a three-dimensional contour image of the underwater small metal target, including: based on the electromagnetic scattering field information of the x component, y component, and z component corresponding to each receiving sensor and the target passing characteristic curve of the x component, y component, and z component, using array coordinates and trajectory parameters to construct a two-dimensional coordinate system in MATLAB software, where the x-axis represents the motion trajectory of the underwater detection device, and the y-axis represents the distance between two adjacent receiving sensors in the receiving sensor array; visualizing the amplitude of the electromagnetic scattering field information of the x component, y component, and z component based on Jet color to obtain contour imaging diagrams of the x component, y component, and z component, and combining the contour imaging diagrams of the x component, y component, and z component to obtain a three-dimensional contour image of the underwater small metal target.

[0016] Optionally, the shape of the underwater metal small target is identified based on the three-dimensional contour image of the underwater metal small target, including: comprehensive identification based on the three-dimensional contour image obtained from each underwater operation, and then auxiliary judgment is performed based on the Jet color in the contour imaging image of the x component, y component, and z component obtained from each underwater operation, and finally the shape, structure and intersection situation of the underwater metal small target are identified. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the related technologies, the following is a brief introduction to the drawings required for use in the embodiments of the present application or the description of the related technologies. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 This is a flow chart of a single-transmitter-multiple-receiver underwater small metal target electromagnetic induction detection method provided in one embodiment of the present application; Figure 2 is a structural diagram of a single-transmit multiple-receive antenna system provided in one embodiment of the present application; Figure 3 This is a schematic diagram of detecting a small underwater cylindrical metal target provided in one embodiment of the present application; Figure 4 is a top view of a small underwater cylindrical metal target provided in one embodiment of the present application; Figure 5 This is a schematic diagram of detecting a small underwater spherical metal target provided in one embodiment of the present application; Figure 6 is a top view of a small underwater spherical metal target provided in one embodiment of the present application; Figure 7 This is a schematic diagram of a target passing characteristic curve obtained by detecting a small underwater cylindrical metal target, provided in one embodiment of the present application; Figure 8 Provided in one embodiment of the present application, when detecting a small underwater cylindrical metal target, the three-dimensional contour images corresponding to different operating distances h are obtained when the intersection angle θ is fixed at 0 degrees and the operating frequency f of the transmitting antenna is 1 kHz; Figure 9 Provided in one embodiment of the present application, when detecting a small underwater cylindrical metal target, with a fixed effective distance h of 2m and an operating frequency f of the transmitting antenna of 1kHz, are three-dimensional contour images corresponding to different intersection angles θ; Figure 10 Provided in one embodiment of the present application, when detecting a small underwater cylindrical metal target, with a fixed intersection angle θ of 0 degrees and an operating distance h of 2 meters, are three-dimensional contour images corresponding to different operating frequencies f of the transmitting antenna; Figure 11 This is a schematic diagram of a target passing characteristic curve obtained by detecting a small underwater spherical metal target, provided in one embodiment of the present application; Figure 12Provided in one embodiment of the present application, when detecting a small underwater spherical metal target, the three-dimensional contour images corresponding to different operating distances h are obtained when the intersection angle θ is fixed at 0 degrees and the operating frequency f of the transmitting antenna is 1 kHz; Figure 13 Provided in one embodiment of the present application, when detecting a small underwater spherical metal target, with a fixed intersection angle θ of 0 degrees and an operating distance h of 2 meters, are three-dimensional contour images corresponding to different operating frequencies f of the transmitting antenna; Figure 14 This is a structural diagram of a single-transmitter, multi-receiver underwater small metal target electromagnetic induction detection system provided in another embodiment of the present application; Figure 15 It is a structural diagram of an electronic device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below with reference to the accompanying drawings. However, it will be understood by those skilled in the art that in each embodiment of the present application, many technical details are proposed to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can be implemented. The division of the following embodiments is for convenience of description and should not constitute any limitation to the specific implementation of the present application. The various embodiments can be combined with each other and referenced to each other under the premise of no contradiction.

[0020] An embodiment of the present application proposes a single-transmitter, multiple-receiver underwater metal small target electromagnetic induction detection method, which is implemented based on a single-transmitter, multiple-receiver antenna system composed of a transmitting antenna and multiple receiving sensors, and is applied to a server. The following is a specific description of the implementation details of the single-transmitter, multiple-receiver underwater metal small target electromagnetic induction detection method proposed in this embodiment. The following content is only the implementation details provided for the convenience of understanding and is not necessary for the implementation of this solution.

[0021] The specific process of the single-transmit-multiple-receive electromagnetic induction detection method for underwater small metal targets proposed in this embodiment can be as follows: Figure 1 Shown, including: Step 11: determine the small underwater metal target to be detected, and plan a detection route under the small underwater metal target according to different effective distances and different intersection angles.

[0022] In practice, the server first determines the approximate location of the underwater metal target to be detected. It then plans detection routes below the target based on different ranges and intersection angles. The range refers to the distance between the underwater detection device and the target during detection, while the intersection angle refers to the angle between the device's direction of travel and the target's axis. Combining different ranges and intersection angles creates a number of detection routes.

[0023] In one example, when planning a detection route, different effective distances are set in a range from 1 m to 3 m, and different intersection angles are set in a range from 0 degrees to 90 degrees.

[0024] In one example, when planning a detection route, different effective distances are set to 1m, 2m, and 3m, and different intersection angles are set to 0 degrees, 30 degrees, 45 degrees, 60 degrees, and 90 degrees. Based on the pairwise combinations of different effective distances and different intersection angles, 15 detection routes are planned in sequence.

[0025] Step 12: Fix the single-transmit multiple-receive antenna system on the underwater vehicle through a rigid connection to form an underwater detection device. In the underwater detection device, multiple receiving sensors form a receiving sensor array, the spacing between two adjacent receiving sensors is equal, and the vertical distance between the transmitting antenna and the receiving sensor array is fixed.

[0026] In a specific implementation, the single-transmit multiple-receive antenna system consists of a transmitting antenna and multiple receiving sensors. By fixing the single-transmit multiple-receive antenna system on an underwater vehicle through a rigid connection, an underwater detection device can be formed. In the underwater detection device, multiple receiving sensors form a receiving sensor array, and the spacing between two adjacent receiving sensors is equal. The vertical distance between the transmitting antenna and the receiving sensor array is fixed.

[0027] In one example, for a single-transmit multiple-receive antenna system, the transmitting antenna is a magnetic dipole structure, its operating frequency is set in the range of 100 Hz to 30 kHz, the spacing between two adjacent receiving sensors is set in the range of 0.1 m to 0.5 m, and the vertical distance between the transmitting antenna and the receiving sensor array is set in the range of 0.5 m to 2 m.

[0028] In one example, the specific structure of the single-transmit multiple-receive antenna system can be as follows: Figure 2As shown, the system includes a transmitting antenna and eleven receiving sensors, arranged in a linear array and spaced evenly apart. The spacing between adjacent receiving sensors is 0.2 meters, and the vertical distance between the transmitting antenna and the receiving sensor array is 1 meter. This design enables the eleven receiving sensors to receive signals from different angles.

[0029] In one example, the underwater vehicle may be an ROV or an AUV.

[0030] Step 13, perform underwater operations, control the underwater detection device to pass under the underwater small metal target according to the detection route, the transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive signals.

[0031] In the specific implementation, the underwater detection device is ready. After completing the planning of the detection route, the server can start to instruct the underwater detection device to perform underwater operations and control the underwater detection device to pass under the small underwater metal target according to the detection route. During the navigation of the underwater detection device, the transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive signals from different angles.

[0032] It's understandable that the low-frequency electromagnetic waves radiated by the transmitting antenna are the primary field. This primary field propagates underwater until it reaches the small underwater metal target. The surface of the small underwater metal target then radiates an electromagnetic field, known as the scattered field. Due to the differences in the shape and electromagnetic properties of the small underwater metal target, the scattered field also exhibits different characteristics. These scattered fields are then received by an array of receiving sensors positioned underwater. Based on the received scattered signals, the electromagnetic scattering characteristics of the small underwater metal target are analyzed, allowing the shape, structure, and intersection situation of the small underwater metal target to be accurately detected.

[0033] In one example, for underwater operations, the server set three different operating frequencies for the transmitting antenna: 1kHz, 10kHz, and 30kHz. By combining the three different operating frequencies with 15 different detection routes, 45 underwater operations can be configured. During each underwater operation, the server needs to control the underwater detection device to pass under the small underwater metal target according to the corresponding detection route. The transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world based on the corresponding operating frequency, and multiple receiving sensors receive the signals.

[0034] In one example, Figure 3 As shown, the underwater metal small target is a cylinder, hereinafter referred to as the underwater cylindrical metal small target, the length of the cylinder The radius is 5m is 0.25m. In the process of detecting small underwater cylindrical metal targets, the underwater detection device always follows the Plane motion, let the action distance be , that is, the vertical distance from the plane where the single-transmitter and multiple-receiver antenna system of the underwater detection device is located to the bottom of the cylinder, and the intersection angle is , which is the angle between the trajectory of the underwater detection device and the axis of the cylinder. Under the influence of the radiation field generated by the transmitting antenna, the surface of the cylinder generates a secondary field (i.e., a scattered field), which is received and captured by the receiving sensor array. Figure 4 This is a top view of a small underwater metal target. Figure 4 The intersection angle can be seen more clearly in .

[0035] In one example, Figure 5 As shown, the underwater metal small target is a sphere, hereinafter referred to as the underwater spherical metal small target, the diameter of the sphere is 0.8m. In the process of detecting small underwater spherical metal targets, the underwater detection device always follows the Plane motion, let the action distance be , that is, the vertical distance from the plane where the single-transmitter and multiple-receiver antenna system of the underwater detection device is located to the bottom of the sphere, and the intersection angle is , which is the angle between the trajectory of the underwater detection device and the axis of the sphere. Under the influence of the radiation field generated by the transmitting antenna, the surface of the sphere generates a secondary field, which is received and captured by the receiving sensor array. Figure 6 This is a top view of a small underwater metal target. Figure 6 The intersection angle can be seen more clearly in .

[0036] Step 14: After completing the underwater operation, the signals received by each receiving sensor are processed to obtain the electromagnetic scattering field information of the underwater small metal target. The electromagnetic scattering field information is then visualized to finally obtain a target passing characteristic curve from each receiving sensor.

[0037] Step 15: Perform imaging operations based on the electromagnetic scattering field information corresponding to each receiving sensor and the target passing characteristic curve to obtain a three-dimensional contour image of the underwater small metal target, thereby identifying the shape of the underwater small metal target based on the three-dimensional contour image of the underwater small metal target.

[0038] In practice, after completing underwater operations, the server processes the signals received by each receiving sensor to obtain electromagnetic scattering field information of the underwater small metal target. This information is then visualized, ultimately generating a target transit characteristic curve from each receiving sensor. These target transit characteristic curves are essentially amplitude-frequency curves and serve as a crucial reference for subsequent imaging. Once these curves are obtained, the server can perform imaging operations based on the electromagnetic scattering field information corresponding to each receiving sensor and the target transit characteristic curves, generating a 3D contour image of the underwater small metal target. This allows the server to identify the shape of the underwater small metal target based on the 3D contour image.

[0039] In one example, the server needs to filter, adaptively cancel, and feature extract the signals received by each receiving sensor in sequence to obtain the electromagnetic scattering field information of the x-component, y-component, and z-component of the underwater small metal target. Then, the electromagnetic scattering field information of the x-component, y-component, and z-component of the underwater small metal target is visualized by curve fitting. Finally, the target passing characteristic curves of the x-component, y-component, and z-component are obtained from each receiving sensor, that is, the amplitude-frequency characteristic curves of the x-component, y-component, and z-component.

[0040] In one example, the server constructs a two-dimensional coordinate system in MATLAB using array coordinates and trajectory parameters based on the electromagnetic scattering field information and target passage characteristic curves corresponding to the x, y, and z components of each receiving sensor. The x-axis represents the motion trajectory of the underwater detection device, and the y-axis represents the distance between two adjacent receiving sensors in the receiving sensor array. Next, the server visualizes the amplitude of the electromagnetic scattering field information of the x, y, and z components using Jet color, generating contour images of the x, y, and z components. These contour images are then combined to create a three-dimensional contour image of the small underwater metal target.

[0041] In one example, an underwater detection device detects a small cylindrical metal target underwater. Figure 7 This is a schematic diagram of the target passing characteristic curve obtained by detecting a small underwater cylindrical metal target. Figure 7 The corresponding detection route has an effective range of 2m, an intersection angle of 45 degrees, an operating frequency of the transmitting antenna of 1kHz, a magnetic moment direction generated by the transmitting antenna magnetic dipole of vertical direction, and a magnetic moment magnitude of 60Am. 2 signal.

[0042] In one example, an underwater detection device detects a small spherical metal target underwater. Figure 11 This is a schematic diagram of the target passing characteristic curve obtained by detecting a small underwater spherical metal target. Figure 11 The corresponding detection route has an effective range of 2m, an intersection angle of 0 degrees, an operating frequency of the transmitting antenna of 1kHz, a magnetic moment direction generated by the transmitting antenna magnetic dipole of vertical direction, and a magnetic moment magnitude of 60Am. 2 signal.

[0043] For different ranges, intersection angles, and operating frequencies of the transmitting antenna, the resulting three-dimensional contours are quite different, especially in terms of approximate shape and Jet color.

[0044] Figure 8 When detecting small underwater cylindrical metal targets, the intersection angle is fixed. is 0 degrees, the operating frequency of the transmitting antenna At 1kHz, different working distances The corresponding 3D contour image.

[0045] Figure 9 It is a fixed effective distance when detecting small cylindrical metal targets underwater. The operating frequency of the transmitting antenna is 2m. For 1kHz, different intersection angles The corresponding 3D contour image.

[0046] Figure 10 When detecting small underwater cylindrical metal targets, the intersection angle is fixed. 0 degrees, effective distance For 2m, the different operating frequencies of the transmitting antenna The corresponding 3D contour image.

[0047] Figure 12 When detecting small underwater spherical metal targets, the intersection angle is fixed. is 0 degrees, the operating frequency of the transmitting antenna At 1kHz, different working distances The corresponding 3D contour image.

[0048] Figure 13 When detecting small underwater spherical metal targets, the intersection angle is fixed. for Degrees, operating range For 2m, the different operating frequencies of the transmitting antenna The corresponding 3D contour image.

[0049] It should be noted that for small underwater spherical metal targets, due to the completely symmetrical structure of the sphere, the electromagnetic scattering field in all directions of the sphere is the same, and the difference between detection from different intersection angles is not very large, so it is not shown.

[0050] from Figures 8 to 10 , Figures 12 to 13 It can be seen that by receiving the electromagnetic scattering field data collected by the sensor array, the geometric outline of the underwater small metal target can be clearly reconstructed, thereby identifying the shape of the underwater small metal target.

[0051] from Figure 8 and Figure 12 It can be seen from the figure that, for both cylindrical and spherical underwater metal small targets, the amplitude of the electromagnetic scattering field decreases with the increase of the effective distance.

[0052] from Figure 9 It can be seen from the figure that the signal width of the underwater cylindrical metal small target decreases with the increase of the intersection angle.

[0053] from Figure 10 and Figure 13 It can be seen from the figure that, for small underwater metal targets, whether they are cylindrical or spherical, in the low frequency band from 1kHz to 30kHz, the amplitude of the electromagnetic scattering field decreases as the operating frequency of the transmitting antenna increases.

[0054] It should be noted that the underwater posture of small metal targets is uncertain. If only one detection is performed, it is impossible to accurately identify small underwater metal targets. For example, small cylindrical underwater metal targets and small rectangular underwater metal targets are similar at certain angles. Therefore, the server needs to perform comprehensive recognition based on the three-dimensional contour image obtained from each underwater operation, and then combine the jet color in the contour imaging image of the x-component, y-component, and z-component components obtained from each underwater operation for auxiliary judgment, ultimately identifying the shape, structure, and intersection situation of the small underwater metal targets.

[0055] Taking the underwater cylindrical metal small target and the underwater rectangular metal small target as examples, when the intersection angle is 0 degrees, the contours in the z-component contour imaging image are approximately rectangular, but the Jet color values ​​are different. The middle part of the z-component contour imaging image of the underwater cylindrical metal small target is reddish, while the color distribution in the z-component contour imaging image of the underwater rectangular metal small target is relatively uniform.

[0056] This embodiment proposes a single-transmit, multi-receive electromagnetic induction detection method for small underwater metal targets. This method is based on a single-transmit, multi-receive antenna system consisting of a transmitting antenna and multiple receiving sensors. Compared to traditional single-transmit, single-receive antenna systems, the single-transmit, multi-receive antenna system can detect small underwater metal targets with smaller sizes and weaker electromagnetic signals. It can complete the detection of specific underwater areas in a shorter time, greatly shortening the detection cycle and well meeting the demand for rapid detection in practical applications. By rigidly connecting such a single-transmit, multi-receive antenna system to an underwater vehicle, an underwater detection device with very high detection sensitivity and resolution can be obtained. When formulating the detection route, different effective ranges and different intersection angles are combined to ensure that the underwater detection device can detect small underwater metal targets from multiple angles and distances, thereby enhancing the accuracy of detection and subsequent identification. When conducting underwater operations, the transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive signals. After completing the underwater operations, the signals received by each receiving sensor are processed. The multi-angle signals collected by each receiving sensor contain rich spatial information of the underwater small metal targets. After processing, a three-dimensional contour image of the underwater small metal targets can be constructed. This imaging capability helps to more intuitively display the shape and structure of the underwater small metal targets, so that the characteristics and types of the underwater small metal targets can be more clearly identified, thereby greatly improving the accuracy and reliability of recognition.

[0057] The steps of the various methods described above are divided for clarity of description only. During implementation, they can be combined into a single step, or some steps can be split into multiple steps. As long as they contain the same logical relationships, they are all within the scope of protection of this application. Adding minor modifications or introducing minor designs to the algorithm or process without changing the core design of the algorithm or process is also within the scope of protection of this application.

[0058] Another embodiment of the present application proposes a single-transmitter, multiple-receiver underwater metal small target electromagnetic induction detection system. The following is a detailed description of the single-transmitter, multiple-receiver underwater metal small target electromagnetic induction detection system proposed in this embodiment. The following content is only the implementation details provided for ease of understanding and is not necessary for the implementation of this example. Figure 14 This is a structural diagram of a single-transmitter, multiple-receiver underwater small metal target electromagnetic induction detection system proposed in this embodiment, including: a detection route planning module 31, an underwater detection device assembly module 32, an underwater detection device 33, an underwater operation command module 34, a target passing characteristic curve drawing module 35 and a three-dimensional contour imaging recognition module 36.

[0059] The detection route planning module 31 is used to determine the underwater small metal target 21 that needs to be detected, and plan the detection route under the underwater small metal target 21 according to different working distances and different intersection angles.

[0060] The underwater detection device assembly module 32 is used to fix the single-transmitter multi-receiver antenna system 22 composed of a transmitting antenna and multiple receiving sensors on the underwater vehicle 23 through a rigid connection to form an underwater detection device 33. In the underwater detection device 33, multiple receiving sensors form a receiving sensor array, the spacing between two adjacent receiving sensors is equal, and the vertical distance between the transmitting antenna and the receiving sensor array is fixed.

[0061] The underwater operation command module 34 is used to control the underwater detection device 33 to pass under the underwater small metal target 21 according to the detection route during the underwater operation, instruct the transmitting antenna to continuously radiate low-frequency electromagnetic waves to the outside world, and multiple receiving sensors to receive signals.

[0062] The target passing characteristic curve drawing module 35 is used to process the signals received by each receiving sensor after completing the underwater operation, obtain the electromagnetic scattering field information of the underwater small metal target 21, and then visualize the electromagnetic scattering field information to finally obtain a target passing characteristic curve from each receiving sensor.

[0063] The three-dimensional contour imaging recognition module 36 is used to perform imaging operations based on the electromagnetic scattering field information corresponding to each receiving sensor and the target passing characteristic curve to obtain a three-dimensional contour image of the underwater small metal target 21, thereby recognizing the shape of the underwater small metal target 21 based on the three-dimensional contour image of the underwater small metal target 21.

[0064] It is worth mentioning that all modules involved in this embodiment are logical modules. In actual applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. In addition, to highlight the innovation of this application, this embodiment does not include units that are not closely related to solving the technical problem proposed by this application. However, this does not mean that other units do not exist in this embodiment.

[0065] It is not difficult to find that this embodiment is a system embodiment corresponding to the above-mentioned method embodiment. This embodiment can be implemented in conjunction with the above-mentioned method embodiment. The relevant technical details and technical effects mentioned in the above-mentioned method embodiment are still valid in this embodiment. To reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the above-mentioned method embodiment.

[0066] Another embodiment of the present application provides an electronic device, the specific structure of which can be as follows: Figure 15 As shown, it includes: at least one processor 41; and a memory 42 communicatively connected to the at least one processor 41; wherein the memory 42 stores instructions that can be executed by the at least one processor 41, and the instructions are executed by the at least one processor 41 to enable the at least one processor 41 to execute a single-transmitter-multiple-receiver underwater metal small target electromagnetic induction detection method as described in the above method embodiment.

[0067] The memory and processor are connected using a bus. The bus can include any number of interconnected buses and bridges, and the bus can connect various circuits of one or more processors and memories. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits. These are all well known in the art and therefore will not be described further in this article. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single component or multiple components, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. Data processed by the processor is transmitted on a wireless medium via an antenna. Furthermore, the antenna also receives data and transmits it to the processor.

[0068] The processor is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory can be used to store data used by the processor when performing operations.

[0069] Another embodiment of the present application proposes a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement a single-transmitter-multiple-receiver underwater metal small target electromagnetic induction detection method as described in the above method embodiment.

[0070] That is, those skilled in the art will understand that all or part of the steps in the above-described method embodiments can be implemented by instructing the relevant hardware through a program. The program is stored in a storage medium and includes a number of instructions for causing a device (such as a microcontroller or chip) or a processor to execute all or part of the steps in the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, ROM, RAM, a magnetic disk, or an optical disk.

[0071] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present application, and that in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A single-transmitter-multiple-receiver electromagnetic induction detection method for underwater small metal targets, based on a single-transmitter-multiple-receiver antenna system consisting of a transmitting antenna and multiple receiving sensors, characterized in that: The method comprises: Determine the small underwater metal target to be detected, and plan the detection route under the small underwater metal target according to different working distances and different intersection angles; A single-transmitter, multiple-receiver antenna system is fixed to an underwater vehicle through a rigid connection to form an underwater detection device. In the underwater detection device, multiple receiving sensors form a receiving sensor array, the spacing between two adjacent receiving sensors is equal, and the vertical distance between the transmitting antenna and the receiving sensor array is fixed; During underwater operations, the underwater detection device is controlled to pass under the small underwater metal target according to the detection route. The transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive the signals. After completing the underwater operation, the signals received by each receiving sensor are processed to obtain the electromagnetic scattering field information of the underwater small metal target. The electromagnetic scattering field information is then visualized and a target passing characteristic curve is finally obtained from each receiving sensor. Based on the electromagnetic scattering field information corresponding to each receiving sensor and the target passing characteristic curve, an imaging operation is performed to obtain a three-dimensional contour image of the underwater small metal target, and thus the shape of the underwater small metal target is recognized based on the three-dimensional contour image of the underwater small metal target.

2. The single-transmit-multiple-receive electromagnetic induction detection method for underwater small metal targets according to claim 1 is characterized in that: When planning a detection route, the range of different effective distances is 1m to 3m, and the range of different intersection angles is 0 degrees to 90 degrees; In the underwater detection device, the transmitting antenna is a magnetic dipole structure, and its operating frequency can be set in the range of 100Hz to 30kHz. The spacing between two adjacent receiving sensors can be set in the range of 0.1m to 0.5m, and the vertical distance between the transmitting antenna and the receiving sensor array can be set in the range of 0.5m to 2m.

3. The single-transmit-multiple-receive electromagnetic induction detection method for underwater small metal targets according to claim 1 is characterized in that: When planning the detection routes, different effective distances were set to 1m, 2m, and 3m, and different intersection angles were set to 0 degrees, 30 degrees, 45 degrees, 60 degrees, and 90 degrees. Based on the pairwise combinations of different effective distances and different intersection angles, 15 detection routes were planned in sequence.

4. The single-transmit-multiple-receive electromagnetic induction detection method for underwater small metal targets according to claim 3 is characterized in that: During underwater operations, the underwater detection device is controlled to pass under the small underwater metal target according to the detection route. The transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world, and multiple receiving sensors receive signals, including: Set three different operating frequencies for the transmitting antenna, namely 1kHz, 10kHz, and 30kHz; 45 underwater operations were configured based on 3 different operating frequencies and 15 different detection routes; During each underwater operation, the underwater detection device is controlled to pass under the small underwater metal target according to the corresponding detection route. The transmitting antenna continuously radiates low-frequency electromagnetic waves to the outside world based on the corresponding working frequency, and multiple receiving sensors receive the signals.

5. The single-transmit-multiple-receive electromagnetic induction detection method for underwater small metal targets according to claim 4 is characterized in that: The signals received by each receiving sensor are processed to obtain the electromagnetic scattering field information of the underwater small metal target. The electromagnetic scattering field information is then visualized and a target passing characteristic curve is finally obtained from each receiving sensor, including: The signals received by each receiving sensor are filtered, adaptively cancelled and feature extracted in sequence to obtain the electromagnetic scattering field information of the x-component, y-component and z-component of the underwater small metal target; The electromagnetic scattering field information of the x-component, y-component, and z-component of the underwater small metal target is visualized by curve fitting. Finally, the target passage characteristic curves of the x-component, y-component, and z-component, that is, the amplitude-frequency characteristic curves of the x-component, y-component, and z-component, are obtained from each receiving sensor.

6. The single-transmit-multiple-receive electromagnetic induction detection method for underwater small metal targets according to claim 5, characterized in that: Based on the electromagnetic scattering field information corresponding to each receiving sensor and the target passing characteristic curve, an imaging operation is performed to obtain a three-dimensional contour image of a small underwater metal target, including: Based on the electromagnetic scattering field information of the x-component, y-component, and z-component corresponding to each receiving sensor and the target passing characteristic curve of the x-component, y-component, and z-component, a two-dimensional coordinate system is constructed in MATLAB software using array coordinates and trajectory parameters. The x-axis represents the motion trajectory of the underwater detection device, and the y-axis represents the distance between two adjacent receiving sensors in the receiving sensor array. The amplitude of the electromagnetic scattering field information of the x-component, y-component, and z-component is visualized based on Jet color to obtain the contour imaging maps of the x-component, y-component, and z-component. The contour imaging maps of the x-component, y-component, and z-component are combined to obtain the three-dimensional contour image of the underwater small metal target.

7. The single-transmit-multiple-receive electromagnetic induction detection method for underwater small metal targets according to claim 6, characterized in that: The shape of the underwater small metal target is recognized based on the 3D contour image of the underwater small metal target, including: Comprehensive recognition is performed based on the three-dimensional contour image obtained from each underwater operation, and auxiliary judgment is performed based on the jet color in the contour imaging image of the x-component, y-component, and z-component obtained from each underwater operation, and finally the shape, structure, and intersection situation of small underwater metal targets are identified.

8. A single-transmitter, multiple-receiver underwater small metal target electromagnetic induction detection system, characterized in that: include: The detection route planning module is used to determine the underwater small metal targets that need to be detected, and plan the detection routes under the underwater small metal targets according to different working distances and different intersection angles; An underwater detection device assembly module is used to secure a single-transmitter, multiple-receiver antenna system consisting of a transmitting antenna and multiple receiving sensors to an underwater vehicle through a rigid connection to form an underwater detection device. In the underwater detection device, the multiple receiving sensors form a receiving sensor array, the spacing between adjacent receiving sensors is equal, and the vertical distance between the transmitting antenna and the receiving sensor array is fixed; The underwater operation command module is used to control the underwater detection device to pass under the underwater small metal target according to the detection route during underwater operations, instruct the transmitting antenna to continuously radiate low-frequency electromagnetic waves to the outside world, and multiple receiving sensors to receive signals; The target passage characteristic curve drawing module is used to process the signals received by each receiving sensor after completing underwater operations, obtain the electromagnetic scattering field information of the underwater small metal target, and then visualize the electromagnetic scattering field information to finally obtain a target passage characteristic curve from each receiving sensor; The three-dimensional contour imaging recognition module is used to perform imaging operations based on the electromagnetic scattering field information corresponding to each receiving sensor and the target passing characteristic curve to obtain a three-dimensional contour image of the underwater small metal target, thereby recognizing the shape of the underwater small metal target based on the three-dimensional contour image of the underwater small metal target.

9. An electronic device, characterized in that: include: at least one processor; and, a memory communicatively coupled to the at least one processor; In which, the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute a single-transmitter-multiple-receiver underwater metal small target electromagnetic induction detection method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it can implement the single-transmit-multiple-receive electromagnetic induction detection method for small underwater metal targets according to any one of claims 1 to 7.

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