A full-sea-depth working high-frequency multi-channel wide-bandwidth directivity receiving array and an implementation method thereof

Abstract

This invention discloses a high-frequency, multi-channel, wide-bandwidth directional receiving array capable of operating at full ocean depth. The array includes an array housing and at least one receiving array module. Each module comprises an array frame and several ceramic elements. The array frame has a porous mesh structure with reinforcing frames on its front and rear sides. The number of ceramic elements corresponds to the number of mesh holes in the array frame, and the ceramic elements are placed within the corresponding mesh holes. An upper matching layer and a lower matching layer are respectively provided on the upper and lower surfaces of the array frame. Corresponding cutting marks are provided on the reinforcing frames on both sides. The upper matching layer has slots cut at the front and rear of the slots, which communicate with the mesh holes below. This invention solves the problem of simultaneously achieving wide bandwidth and wide directivity in multi-channel arrays, improving the detection coverage of multibeam bathysound sonar.

Description

Technical fields:

[0001] This invention belongs to the field of underwater sensor technology, specifically relating to a high-frequency, multi-channel, wide-bandwidth directional receiving array that operates at full ocean depth and its implementation method. Background technology:

[0002] The ocean is a crucial pillar of my country's sustainable development, and marine development has risen to the level of a national strategy. Venturing into the deep blue sea is not only an essential step in implementing the national strategy of building a maritime power, but also an inevitable choice to ensure economic development needs, safeguard my country's maritime rights and interests, and maintain its maritime security. Deep-sea UUVs, ROVs, and other unmanned platforms will be important carriers for developing and utilizing the ocean. Information is paramount for action decisions, and the acoustic and visual sensors on these marine unmanned platforms can provide real-time, high-resolution acoustic images as a basis for decision-making in diverse underwater operations such as safe navigation and obstacle avoidance, target search, terrain detection, and resource exploration. Therefore, multi-beam forward-looking obstacle avoidance and multi-beam bathymetry sonar systems are needed to provide "visuals" for these marine unmanned platforms, enabling them to see, differentiate, and accurately target underwater.

[0003] However, traditional multi-channel array implementations often employ independent element linear arrays. This independent element array method is unsuitable for high-frequency, small-sized array designs, and the spacing between elements after arraying is inaccurate. For example, Chinese Patent Publication No. CN105784095B uses piezoelectric ceramic particles bonded to copper strips, then bonding a matching layer to form a single receiving hydrophone. Multiple hydrophones are then combined to form a receiving hydrophone module, and finally, eight receiving hydrophone modules form a cylindrical array. This method is complex to manufacture and makes it difficult to guarantee the consistency between hydrophones. Another example is a full-ocean-depth high-frequency arc-shaped transmitting array disclosed in Chinese Patent No. 202110800251.8. This arc-shaped transmitting array has a semi-cylindrical shape and an oil-filled cavity, enabling full-ocean-depth operation and wide-fan-shaped transmission. The arc-shaped transmitting array is composed of independent arc-shaped transmitting units, achieving wide horizontal coverage using independent units, but it is unsuitable for high-frequency array designs with small element spacing.

[0004] Therefore, a high-frequency, multi-channel, wide-bandwidth, directional receiver array is needed to meet the requirements of marine unmanned carrier platforms, achieving high consistency, wide bandwidth, wide directionality, and high reliability among each channel. Summary of the Invention:

[0005] The technical problem to be solved by the present invention is to provide a high-frequency multi-channel wide-bandwidth directional receiving array for full ocean depth operation and its implementation method, thereby solving the problem of simultaneously achieving wide bandwidth and wide directivity of elements in a multi-channel array and improving the detection coverage of multibeam bathysound sonar.

[0006] The technical solution of the present invention is to provide a high-frequency, multi-channel, wide-bandwidth directional receiving array for full ocean depth operation, including an array housing and at least one receiving array module. The receiving array module includes an array frame and several ceramic elements. The array frame is a porous grid structure, and reinforcing frames are provided on the front and rear sides of the array frame. The number of ceramic elements corresponds to the number of grid holes in the array frame. The ceramic elements are placed in the corresponding grid holes. An upper matching layer and a lower matching layer are respectively provided on the upper and lower surfaces of the array frame. Corresponding knife-aligning marks are provided on the reinforcing frames on the front and rear sides. The upper matching layer has slots cut on the front and rear sides corresponding to the knife-aligning marks. The slots are connected to the grid holes below.

[0007] The receiving array module is installed inside the array housing. The slots of the receiving array module and the grid holes of the array frame are filled with decoupling material. A pressure plate covers the receiving array module and is sealed to the array housing. A sound-permeable plate is sealed above the pressure plate. The lower part of the array housing is a cavity structure. An oil filling port is also provided on the side of the array housing. Hydraulic oil is filled into the cavity of the array housing through the oil filling port. A vertically arranged watertight cable is also provided at the bottom of the array housing.

[0008] Preferably, the reinforcing frame is a metal frame, and the array frame and the reinforcing frame are integrally molded by injection molding. The frame is used to improve strength, act as a reinforcing rib, and fix the receiving array module in the array housing. For example, the reinforcing frame has mounting holes, and the array housing and the receiving array module are connected and fixed through the mounting holes on the reinforcing frame.

[0009] Preferably, the spacing between adjacent tool setting marks on the same reinforcing frame is half the wavelength of the operating frequency. The spacing between the tool setting marks is generally half the wavelength of the operating frequency, but it can also be determined based on the array design.

[0010] Preferably, the bottom of the array housing is a receiving cover plate, which is sealed to the housing.

[0011] Preferably, the outer grids on the left and right sides of the array frame are semi-enclosed structures. A semi-enclosed structure means that the outer grids have no outer sides, unlike the middle grid which is enclosed on all four sides. The outer grids have only three sides, which creates a "borderless" design for the receiving array modules, enabling multiple modules to be extended and arrayed while ensuring the spacing between modules.

[0012] As a preferred option, the sound-permeable panel is made of fiberglass.

[0013] Furthermore, the present invention also provides a method for implementing the full-ocean-depth operating high-frequency multi-channel wide-bandwidth directional receiver array as described above, including...

[0014] Prepare the housing, pressure plate, sound-permeable plate, and array frame with metal reinforcement according to the design requirements;

[0015] According to the design requirements, mounting holes and tool setting marks are made on the metal frames on the front and rear sides of the array frame, and the tool setting marks on the metal frames on the front and rear sides correspond one-to-one.

[0016] After the back matching layer is poured into the lower part of the array frame, the ceramic components are placed one by one into the corresponding grid. Then, the front matching layer is poured into the upper part of the array frame, and the front matching layer is cut according to the knife mark on the metal frame to form the receiving array module.

[0017] Multiple receiving array modules are installed into the array housing, the receiving array modules are positioned and fixed through the mounting holes, and decoupling material is filled between the elements before installing the pressure plate and the sound-permeable plate.

[0018] Hydraulic oil is filled through the oil filling port pre-installed on the side of the array housing. The oil filling port is sealed with a plug or sealing cap to ensure pressure balance. Finally, the signal is output through the longitudinal watertight cable at the bottom.

[0019] Compared with the prior art, the present invention has the following advantages after adopting the above solution:

[0020] This invention solves the problem of simultaneously achieving wide bandwidth and wide directivity of elements in a multi-channel array, thereby improving the detection coverage of multibeam sounding sonar. Specifically,

[0021] 1. Multi-channel array independent matching layer design: The metal frame is engraved with a knife-setting mark, which can realize precise cutting of the front matching layer, ultimately achieving wide bandwidth and wide horizontal coverage angle of the multi-channel array elements;

[0022] 2. "Borderless" design of the receiving array module: It can realize the extension and arraying of multiple modules while ensuring the spacing between modules;

[0023] 3. The receiving array uses fiberglass acoustic panels as the acoustic windows of the array, and the empty structural parts of the array are filled with oil. This design is very simple and reliable, and is suitable for operation at all ocean depths.

[0024] To achieve wide bandwidth and wide horizontal coverage angle for multi-channel array elements, precise cutting of the front matching layer is required. Knife marking enables precise positioning of the cutting, thereby ensuring element spacing and achieving element height consistency, wide bandwidth, and wide beam. The array adopts multiple receiving array modules arranged according to application requirements, uses fiberglass acoustic panels as acoustic windows for the array, and fills the empty structural parts of the array with oil. This solves the pressure resistance design of complex large arrays and enables full deep-sea operations. Attached image description:

[0025] Figure 1 This is a schematic diagram of the receiving array module structure.

[0026] Figure 2 This is a schematic diagram of the receiving array structure.

[0027] Figure 3 This is a wide directional diagram according to an embodiment of the present invention.

[0028] Figure 4 This is a graph showing the receiver sensitivity of the present invention. Detailed implementation method:

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0030] This invention discloses a high-frequency, multi-channel, wide-bandwidth directional receiver array that operates at full ocean depth, such as... Figure 1 , 2 As shown, the receiving array module of the present invention includes an array housing 5 and at least one receiving array module 1. The receiving array module 1 includes an array frame 16 and a plurality of ceramic elements 13. The array frame 16 has a multi-hole mesh structure. Reinforcing frames 11 are respectively provided on the front and rear sides of the array frame 16. The reinforcing frames 11 are metal frames and are integrally formed with the array frame 16 by injection molding. The number of ceramic elements 13 corresponds to the number of mesh holes in the array frame 16. The ceramic elements 13 are installed into the corresponding mesh holes of the array frame 16 and a matching layer is poured in through a mold. The upper surface of the array frame 16 is filled with a front matching layer 14 and the lower surface is filled with a rear matching layer 15. A one-to-one corresponding cutting mark 12 is engraved on the front and rear reinforcing frames 11. The front matching layer 14 is precisely cut according to the cutting mark 12 to achieve the wide directivity of the element. During cutting, the front matching layer is cut through vertically according to the blade setting mark, so that the slots cut by the front matching layer are connected with the mesh holes below. In this embodiment, the spacing between adjacent blade setting marks on the same reinforcing frame is half the wavelength of the working frequency.

[0031] like Figure 2 As shown, multiple receiving array modules 1 are installed inside the array housing 5. For easy positioning, the reinforcing frame 11 has openings such as... Figure 1 The mounting holes 17 shown are used to position and fix the receiving array module 1. Furthermore, decoupling material 4 is filled between the elements; that is, the mesh holes of the ceramic elements and the slots cut from the front panel are filled with decoupling material. The sound-permeable plate 2, made of rigid fiberglass, serves as the sound-permeable window of the array. It is fixed and sealed to the pressure plate 3 by screws and sealing rings. The array housing 5 and the pressure plate 3 are sealed by end-face sealing rings. The cavity at the bottom of the array housing 5 is a watertight electronic compartment, and the lower end face is sealed by the receiving cover plate 6 through end-face sealing rings. Additionally, the remaining internal structure of the receiving array utilizes the pre-installed oil filling port 7 on the side of the array housing 5 to fill with hydraulic oil 9. Filling with hydraulic oil ensures pressure balance. All structural materials within the receiving array do not undergo chemical or physical reactions with the hydraulic oil. Finally, the signal is output through the longitudinal watertight cable 8.

[0032] To accurately combine multiple receiver array modules, such as Figure 1 The outermost grid holes on the left and right sides of the array frame shown are semi-closed grid holes, which makes the connection and combination more precise, realizes the extension and arraying of multiple modules and ensures the spacing between modules.

[0033] Figure 3 and Figure 4 The performance of the full-ocean-depth high-frequency multi-channel wide-bandwidth directional receiver array in this embodiment is as follows: the horizontal beamwidth of the receiver element is 123.1° at -6dB, and the receiver sensitivity is -174dB to -169.4dB in the 100kHz to 150kHz frequency band, with a fluctuation of 4.6dB.

[0034] Wide horizontal coverage and high channel consistency of multi-beam receiving arrays are key technologies for the detection coverage of multi-beam depth sounding sonar. Wide directivity is equivalent to increasing the field of view, allowing for a wider field of vision. High channel consistency is more compatible with back-end circuitry and enables low sidelobes.

[0035] Moreover, to achieve wide bandwidth and wide horizontal coverage angle of multi-channel array elements, the front matching layer must be precisely cut. The knife marking can achieve precise positioning of the cut, thereby ensuring the spacing between elements and achieving high consistency, wide bandwidth, and wide beam.

[0036] This invention can be implemented in the following ways, specifically,

[0037] Prepare the housing, pressure plate, sound-permeable plate, and array frame with metal reinforcement according to the design requirements;

[0038] According to the design requirements, mounting holes and tool setting marks are made on the metal frames on the front and rear sides of the array frame, and the tool setting marks on the metal frames on the front and rear sides correspond one-to-one.

[0039] After the back matching layer is poured into the lower part of the array frame, the ceramic components are placed one by one into the corresponding grid. Then, the front matching layer is poured into the upper part of the array frame, and the front matching layer is cut according to the knife mark on the metal frame to form the receiving array module.

[0040] Multiple receiving array modules are installed into the array housing, the receiving array modules are positioned and fixed through the mounting holes, and decoupling material is filled between the elements before installing the pressure plate and the sound-permeable plate.

[0041] Hydraulic oil is filled through the oil filling port pre-installed on the side of the array housing to ensure pressure balance. After filling, the oil filling port is sealed with a plug, and finally the signal is output through the longitudinal watertight cable at the bottom.

[0042] The above description only illustrates preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. Any equivalent structural or procedural modifications made using this specification are included within the patent protection scope of the present invention.

Claims

1. A high-frequency, multi-channel, wide-bandwidth directional receiving array operating at full ocean depth, comprising an array housing and at least one receiving array module, characterized in that: The receiving array module includes an array frame and several ceramic components. The array frame has a porous grid structure. Reinforcing frames are provided on the front and rear sides of the array frame. The number of ceramic components corresponds to the number of grid holes in the array frame. The ceramic components are placed in the corresponding grid holes. The upper and lower surfaces of the array frame are also provided with an upper matching layer and a lower matching layer, respectively. The reinforcing frames on the front and rear sides are provided with corresponding knife-aligning marks. The upper matching layer is cut with slots set at the front and rear corresponding to the knife-aligning marks. The slots are connected to the grid holes below. The receiving array module is mounted inside the array housing. The slots of the receiving array module and the grid holes of the array frame are filled with decoupling material. A pressure plate covers the receiving array module, and the pressure plate is sealed to the array housing. A sound-permeable plate is sealed above the pressure plate. The lower part of the array housing is a cavity structure. An oil filling port is also provided on the side of the array housing. Hydraulic oil is filled into the cavity of the array housing through the oil filling port. A vertically arranged watertight cable is also provided at the bottom of the array housing. The outer grids on the left and right sides of the array frame are semi-closed structures. A semi-closed structure means that the outer grid has only three sides and no outer side. The sound-permeable panel is made of fiberglass.

2. The full-ocean-depth operating high-frequency multi-channel wide-bandwidth directional receiving array according to claim 1, characterized in that: The reinforcing frame is a metal frame, and the array frame and the reinforcing frame are integrally molded by injection molding.

3. The full-ocean-depth operating high-frequency multi-channel wide-bandwidth directional receiving array according to claim 1, characterized in that: The reinforcing frame has mounting holes, and the array housing and the receiving array module are connected and fixed through the mounting holes on the reinforcing frame.

4. The full-ocean-depth operating high-frequency multi-channel wide-bandwidth directional receiving array according to claim 1, characterized in that: The spacing between adjacent tool setting marks on the same reinforcing frame is half the wavelength of the operating frequency.

5. The full-ocean-depth operating high-frequency multi-channel wide-bandwidth directional receiving array according to claim 1, characterized in that: The bottom of the array housing is a receiving cover plate, which is sealed to the housing.

6. A method for implementing a full-ocean-depth operating high-frequency multi-channel wide-bandwidth directional receiving array as described in any one of claims 1-5, characterized in that: include Prepare the housing, pressure plate, sound-permeable plate, and array frame with metal reinforcement according to the design requirements; According to the design requirements, mounting holes and tool setting marks are made on the metal frames on the front and rear sides of the array frame, and the tool setting marks on the metal frames on the front and rear sides correspond one-to-one. After the back matching layer is poured into the lower part of the array frame, the ceramic components are placed one by one into the corresponding grid. Then, the front matching layer is poured into the upper part of the array frame, and the front matching layer is cut according to the knife mark on the metal frame to form the receiving array module. Multiple receiving array modules are installed into the array housing, the receiving array modules are positioned and fixed through the mounting holes, and decoupling material is filled between the elements before installing the pressure plate and the sound-permeable plate. Hydraulic oil is filled through the oil filling port pre-installed on the side of the array housing to ensure pressure balance, and finally the signal is output through the longitudinal watertight cable at the bottom.

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