A high-frequency imaging sonar array structure and design method thereof

Abstract

The present invention relates to a high-frequency imaging sonar array structure and a design method thereof, including a circuit board, a piezoelectric film, an electrode, an electrode sheet, a metal column, a circuit, a wiring board, a metal core, a plug, a cylinder, an end cap, a perfusion layer and a connector, wherein the piezoelectric film is integrated with the circuit board, the electrode, the electrode sheet and the circuit as a sensing element of the sonar array; wherein the circuit board is made of a whole PCB board, a plurality of metal columns are inlaid on the circuit board, and an electrode is inlaid on each of the left and right sides of the circuit board; the piezoelectric film adopts a polyvinylidene fluoride (PVDF) piezoelectric film or a copolymer of difluoroethylene and trifluoroethylene P (VDF‑TrFE) piezoelectric film, and the front and back sides of the piezoelectric film are coated with metal conductive electrodes. The present invention adopts a whole piezoelectric polymer film and a collection and amplification circuit and a structure integrated design, which effectively avoids the design drawbacks of the conventional piezoelectric ceramic sonar array in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of arrays and relates to a high-frequency imaging sonar array structure and a design method thereof. Background Art

[0002] The directivity of the imaging sonar array, the performance consistency of the sensor elements and the adaptability in complex environments are the key factors that determine the imaging quality and detection performance of the sonar system.

[0003] Most existing solutions use 1-3 type piezoelectric ceramic composite materials or piezoelectric ceramic round / square columns as the sensor elements of the sonar array. The sensing area and the performance consistency of the sensor elements are limited by the process, and the integrated design with the acquisition circuit is difficult, and the array is single. Due to the limitation that piezoelectric ceramic elements are difficult to develop on a large scale, and the cutting process of composite materials or single ceramic columns is complicated, this method of assembling large-area sensing is difficult to ensure the performance consistency of each element, and the integrated design of the acquisition circuit, sensor element and hydrophone support structure is difficult, which is difficult to meet the application scenario requirements of imaging sonar. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a high-frequency imaging sonar array structure and a design method thereof. The sensing part of the sonar array in the present invention adopts a whole piezoelectric polymer film and an acquisition amplification circuit and a structure integrated design, which effectively avoids the design drawbacks of the traditional piezoelectric ceramic sonar array in the prior art.

[0005] The technical solution of the present invention is to provide a high-frequency imaging sonar array structure, including a circuit board, a piezoelectric film, an electrode, an electrode sheet, a metal column, a circuit, a wiring board, a metal core, a plug, a cylinder, an end cover, a perfusion layer and a connector. The piezoelectric film is integrated with the circuit board, the electrode, the electrode sheet and the circuit as a sensing element of the sonar array; wherein,

[0006] The circuit board is made of a whole PCB board, and a number of metal pillars are embedded on the circuit board, and an electrode is embedded on each side of the circuit board;

[0007] The piezoelectric film adopts polyvinylidene fluoride (PVDF) piezoelectric film or difluoroethylene and trifluoroethylene copolymer P (VDF-TrFE) piezoelectric film. The thickness and size of the piezoelectric film are designed according to the working frequency band of the sonar array and the impedance matching characteristics of the preamplifier circuit. The front and back sides of the piezoelectric film are coated with metal conductive electrodes. The piezoelectric film is pasted in the middle position of the circuit board and is tightly bonded to the metal column. The metal column is connected to the metal conductive electrode, and the metal column is used as the positive electrode of the piezoelectric film signal input;

[0008] The electrode sheet is made of metal conductive material into a thin sheet, and the electrode sheet is bonded and connected with the piezoelectric film and the electrode;

[0009] The circuit is made of a preamplifier circuit, which is installed on the back of the circuit board. Each sensing element corresponds to a circuit, and the arrangement is consistent with the metal column. The circuit is close to the piezoelectric film. The circuit adopts a single-ended input and single-ended output method. All circuits share a ground wire and a power supply wire, and the ground wire is connected to the electrode.

[0010] The metal core is made of a metal material with good conductivity. The metal core is embedded in the metal column and runs through the circuit board to connect the electrical signal of the sensor element with the circuit.

[0011] The plug has a multi-core cable and is connected to the wiring board. The signal output lines of all sensor primitives are gathered on the wiring board, and the electrical signal amplified by each sensor primitive is gathered on the connector through the multi-core cable;

[0012] The cylinder is made of metal material and serves as the pressure-resistant shell of the acoustic array. The cylinder is connected to the ground wire of the circuit to provide electromagnetic shielding for the sensor element.

[0013] The end cover is made of metal material, and the end cover and the cylinder are watertightly matched. There is a hole on the end cover for installing the connector;

[0014] The perfusion layer is used to make the outermost sensing surface watertight;

[0015] The connector is installed in the hole of the end cover for signal transmission and watertightness.

[0016] The invention uses a piezoelectric polymer film integrated with a circuit board, an electrode structure, and a preamplifier circuit as the sensing element of the sonar array. This design method not only fully utilizes the sensing advantages of the material, but also effectively avoids the design defects of traditional piezoelectric ceramic materials, providing a new design idea for the design of imaging sonar arrays and signal processing methods.

[0017] Preferably, the electrodes are made of metal conductive material into strips, and the electrodes are embedded on the left and right sides of the circuit board and penetrate the circuit board to serve as ground wires for the piezoelectric film signal input.

[0018] Preferably, the metal column is made of metal material, embedded in the hole of the circuit board, with the end faces of the metal column flush with the outer surface of the circuit board and tightly bonded to the piezoelectric film, serving as a hard backing for the piezoelectric film while serving as a signal input and for reflecting sound waves.

[0019] Preferably, the terminal block adopts a close-packed pin design.

[0020] Preferably, the plug adopts a close-packed pin design.

[0021] Preferably, the injection layer is formed by injection of polyurethane or epoxy resin.

[0022] Preferably, the connector is made of a multi-core watertight connector.

[0023] Preferably, an O-ring groove is provided on the outer diameter of the end cover, and the end cover is tightly installed inside the cylinder to be watertight.

[0024] Preferably, the electrode is made of copper or aluminum; the electrode sheet is made of copper or aluminum; the metal column is made of any one of copper, aluminum and stainless steel; the metal core is made of any one of copper, aluminum and stainless steel; the cylinder is made of stainless steel or copper; and the end cap is made of stainless steel or copper.

[0025] Furthermore, the present invention also provides a design method for the high-frequency imaging sonar array structure, which uses a piezoelectric film and a circuit board, an electrode structure, and a circuit integrated design as a sensor element of the sonar array; wherein:

[0026] The circuit board is made of a whole PCB board, and the circuit board is designed with holes distributed according to specified rules, and metal pillars are embedded in the holes;

[0027] The piezoelectric film adopts polyvinylidene fluoride (PVDF) piezoelectric film or difluoroethylene and trifluoroethylene copolymer P (VDF-TrFE) piezoelectric film. The thickness and size of the piezoelectric film are designed according to the working frequency band of the sonar array and the impedance matching characteristics of the preamplifier circuit. The front and back sides of the piezoelectric film are coated with metal conductive electrodes. The piezoelectric film is pasted to the middle position of the circuit board by epoxy resin, and is tightly bonded to the metal column at the same time, so that the metal column and the metal conductive electrode are connected, and the metal column is used as the positive electrode of the piezoelectric film signal input;

[0028] The electrodes are made of metal conductive material in the shape of strips, and the metal conductive material is copper or aluminum. The electrodes are embedded on the left and right sides of the circuit board, penetrate the circuit board, and serve as ground wires for the input of piezoelectric film signals.

[0029] The electrode sheet is made of a metal conductive material such as copper or aluminum, and epoxy resin is used to bond and conduct the electrode sheet to the piezoelectric film and the electrode.

[0030] The metal column is made of any metal material such as copper, aluminum, and stainless steel. The metal column is embedded in the hole of the circuit board, and the end face is flush with the outer surface of the circuit board and is tightly bonded to the piezoelectric film. It serves as a signal input and also as a hard backing for the piezoelectric film to reflect sound waves.

[0031] The circuit is made of a preamplifier circuit and installed on the back of the circuit board. Each sensing element corresponds to a circuit, and the arrangement is consistent with the metal column. The circuit is close to the piezoelectric film and adopts a single-ended input and single-ended output method. All circuits share a ground wire and a power supply wire, and the ground wire is connected to the electrode.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] The present invention adopts the idea of ​​integrated design of piezoelectric film and circuit, which can effectively increase the sensing area of ​​the sonar array, improve the sensitivity of the sensor element and the performance consistency of the element. The array mode can be flexibly adjusted, the working frequency band can be adapted to a wide range, and the sensor element has the advantages of impact resistance and stable performance under high hydrostatic pressure. The development process is relatively simple and reliable, and can improve the imaging effect of the sonar system at the source of the sonar array. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a partial schematic diagram of an embodiment of the present invention.

[0035] Figure 2 Schematic diagram of a circuit and a wiring board according to an embodiment of the present invention.

[0036] Figure 3 Schematic diagram of a metal core according to an embodiment of the present invention.

[0037] Figure 4 FIG. 2 is another partial structural diagram of an embodiment of the present invention.

[0038] Figure 5 It is an exploded view of an embodiment of the present invention.

[0039] Figure 6 It is a schematic structural diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings:

[0041] A high-frequency imaging sonar array structure, such as Figure 1-6 As shown, it includes a circuit board 1, a piezoelectric film 2, an electrode 3, an electrode sheet 4, a metal column 5, a circuit 6, a wiring board 7, a metal core 8, a plug 9, a cylinder 10, an end cover 11, a perfusion layer 12 and a connector 13. The piezoelectric film 2 is integrated with the circuit board 1, the electrode 3, the electrode sheet 4 and the circuit 6 as a sensing element of the sonar array; wherein,

[0042] The circuit board 1 is made of a whole PCB board, and a number of metal pillars 5 are embedded on the circuit board. An electrode 3 is embedded on each of the left and right sides of the circuit board; the electrode 3 is made of metal conductive material into a strip shape, and the electrode 3 is embedded on the left and right sides of the circuit board 1 and penetrates the circuit board 1, serving as a ground wire for the piezoelectric film signal input. In this embodiment, the electrode material is copper; the metal pillar 5 is made of aluminum material, and the metal pillar 5 is embedded in the hole of the circuit board 1. The end faces of the metal pillars are flush with the outer surface of the circuit board 1 and are tightly bonded to the piezoelectric film 2, so that it can be used as a signal input and also as a hard backing for the piezoelectric film 2 to reflect sound waves.

[0043] The piezoelectric film 2 is made of polyvinylidene fluoride piezoelectric film or difluoroethylene and trifluoroethylene copolymer piezoelectric film. The front and back sides of the piezoelectric film 2 are coated with metal conductive electrodes. The piezoelectric film 2 is pasted in the middle position of the circuit board 1 and is tightly bonded to the metal column 5. The metal column 5 is conductively connected to the metal conductive electrode, and the metal column 5 is used as the positive electrode of the piezoelectric film signal input.

[0044] The electrode sheet 4 is made of a metal conductive material and is bonded and connected to the piezoelectric film 2 and the electrode 3.

[0045] The circuit 6 is made of a preamplifier circuit and is installed on the back of the circuit board 1. Each sensing element corresponds to a circuit 6. The arrangement is consistent with the metal column 5. The circuit 6 adopts a single-ended input and single-ended output mode. All circuits 6 share a ground wire and a power supply wire, and the ground wire is connected to the electrode 3.

[0046] The metal core 8 is made of a conductive metal material, is embedded in the metal column 5, and runs through the circuit board 1, and is used to connect the electrical signal of the sensor element with the circuit 6;

[0047] The plug 9 has a multi-core cable and is connected to the terminal block 7. The signal output lines of all sensor elements are converged on the terminal block 7, and the electrical signals amplified by each sensor element are converged on the connector 13 through the multi-core cable. In this embodiment, the plug 9 adopts a pin-type close-packed design, and the terminal block 7 also adopts a pin-type close-packed design.

[0048] The cylinder 10 is made of metal material and serves as a pressure-resistant shell of the acoustic array. The cylinder 10 is connected to the ground wire of the circuit 6 to perform electromagnetic shielding on the sensor element. In this embodiment, the cylinder 10 is made of stainless steel.

[0049] The end cover 11 is made of metal material, specifically stainless steel in this embodiment. The end cover 11 is watertightly matched with the cylinder 10. Specifically, an O-ring groove is provided on the outer diameter of the end cover 11. The end cover 11 is tightly installed inside the cylinder 10 for watertightness. The end cover 11 is also provided with a hole for installing the connector 13.

[0050] The pouring layer 12 is used for watertightness of the outermost sensing surface. In this embodiment, the pouring layer 12 is made of polyurethane or epoxy resin.

[0051] The connector 13 is installed in the hole of the end cover 11 for signal transmission and watertightness. The connector 13 is made of a multi-core watertight connector.

[0052] In the present invention, the design method of the high-frequency imaging sonar array structure is as follows: a piezoelectric film 2 is integrated with a circuit board 1, an electrode 3, an electrode sheet 4, and a circuit 6 as a design concept of a sensor element of the sonar array; wherein:

[0053] The circuit board 1 is made of a whole PCB board. Holes are designed on the circuit board 1 and distributed according to a specified rule. Metal pillars 5 are embedded in the holes. An electrode 3 is embedded on each of the left and right sides of the circuit board 1.

[0054] The piezoelectric film 2 is a polyvinylidene fluoride piezoelectric film or a piezoelectric film of a copolymer of vinylidene fluoride and vinyl trifluoride. The thickness and size of the piezoelectric film 2 are designed according to the working frequency band of the sonar array and the impedance matching characteristics of the preamplifier circuit. The front and back sides of the piezoelectric film 2 are coated with metal conductive electrodes. The piezoelectric film 2 is pasted to the middle position of the circuit board 1 by epoxy resin, and is tightly bonded to the metal column 5, so that the metal column 5 is connected to the metal conductive electrode, and the metal column 5 is used as the positive electrode of the piezoelectric film signal input;

[0055] The electrode 3 is made of a metal conductive material in the shape of a strip, and the metal conductive material is copper or aluminum. The electrode 3 is embedded on the left and right sides of the circuit board 1 and penetrates the circuit board 1, serving as a ground line for the piezoelectric film signal input;

[0056] The electrode sheet 4 is made of a metal conductive material such as copper or aluminum, and the electrode sheet 4 is bonded and connected to the piezoelectric film 2 and the electrode 3 using epoxy resin.

[0057] The metal column 5 is made of any metal material such as copper, aluminum, or stainless steel. The metal column 5 is embedded in the hole of the circuit board 1, and its end face is flush with the outer surface of the circuit board 1 and is tightly bonded to the piezoelectric film 2. It serves as a signal input and also as a hard backing of the piezoelectric film 2 to reflect sound waves.

[0058] Circuit 6 is made of a preamplifier circuit and is installed on the back of the circuit board 1. Each sensor element corresponds to a circuit 6. The arrangement is consistent with the metal column 5 and is adjacent to the sensor element. A single-ended input and single-ended output method is adopted on circuit 6. All circuits 6 share a ground wire and a power supply wire, and the ground wire is connected to the electrode 3.

[0059] The present invention adopts the idea of ​​integrated design of piezoelectric film and circuit, which can effectively increase the sensing area of ​​the sonar array, improve the sensitivity of the sensor element and the performance consistency of the element. The array mode can be flexibly adjusted, the working frequency band can be adapted to a wide range, and the sensor element has the advantages of impact resistance and stable performance under high hydrostatic pressure. The development process is relatively simple and reliable, and can improve the imaging effect of the sonar system at the source of the sonar array.

[0060] The above is only an explanation of the preferred embodiments of the present invention, which should not be construed as a limitation on the claims. Any equivalent process changes made using the present invention specification are included in the patent protection scope of the present invention.

Claims

1. A high-frequency imaging sonar array structure, characterized in that: It includes a circuit board, a piezoelectric film, an electrode, an electrode sheet, a metal column, a circuit, a wiring board, a metal core, a plug, a cylinder, an end cover, a perfusion layer and a connector. The piezoelectric film is integrated with the circuit board, the electrode, the electrode sheet and the circuit as a sensing element of the sonar array; wherein, The circuit board is made of a whole PCB board, and a number of metal pillars are embedded on the circuit board. There is an electrode on each side of the circuit board; The piezoelectric film adopts a copolymer of difluoroethylene and trifluoroethylene piezoelectric film. The front and back sides of the piezoelectric film are coated with metal conductive electrodes. The piezoelectric film is pasted in the middle of the circuit board and is tightly bonded to the metal column. The metal column is connected to the metal conductive electrode, and the metal column is used as the positive electrode of the piezoelectric film signal input; The electrode sheet is made of metal conductive material into a thin sheet, and the electrode sheet is bonded and connected with the piezoelectric film and the electrode; The circuit is made of preamplifier circuit, which is installed on the back of the circuit board. Each sensing element corresponds to a circuit, and the arrangement is consistent with the metal column. The circuit adopts single-ended input and single-ended output. All circuits share the ground wire and power supply wire, and the ground wire is connected to the electrode. The metal core is made of conductive metal material, embedded in the metal column and passing through the circuit board, and is used to connect the electrical signal of the sensor element with the circuit; The plug has a multi-core cable and is connected to the wiring board. The signal output lines of all sensor primitives are gathered on the wiring board, and the electrical signal amplified by each sensor primitive is gathered on the connector through the multi-core cable; The cylinder is made of metal material and serves as the pressure-resistant shell of the acoustic array. The cylinder is connected to the ground wire of the circuit to provide electromagnetic shielding for the sensor element. The end cover is made of metal material, and the end cover and the cylinder are watertightly matched. There is a hole on the end cover for installing the connector; The perfusion layer is used to make the outermost sensing surface watertight; The connector is installed in the hole of the end cover for signal transmission and watertightness.

2. The high-frequency imaging sonar array structure according to claim 1, characterized in that: The electrodes are made of metal conductive material into strips. The electrodes are embedded on the left and right sides of the circuit board and penetrate the circuit board to serve as ground wires for the piezoelectric film signal input.

3. The high-frequency imaging sonar array structure according to claim 1, characterized in that: The metal column is made of metal material and is embedded in the hole of the circuit board. The end faces of the metal column are flush with the outer surface of the circuit board and are tightly bonded to the piezoelectric film. It serves as a hard backing for the piezoelectric film while serving as a signal input and for reflecting sound waves.

4. The high-frequency imaging sonar array structure according to claim 1, characterized in that: The terminal block adopts a close-packed pin design.

5. The high-frequency imaging sonar array structure according to claim 1, characterized in that: The plug adopts a close-packed pin design.

6. The high-frequency imaging sonar array structure according to claim 1, characterized in that: The injection layer is made of polyurethane or epoxy resin.

7. The high-frequency imaging sonar array structure according to claim 1, characterized in that: The connector is made of multi-core watertight connector.

8. The high-frequency imaging sonar array structure according to claim 1, characterized in that: An O-ring groove is provided on the outer diameter of the end cover, and the end cover is tightly installed inside the cylinder to be watertight.

9. The high-frequency imaging sonar array structure according to claim 1, characterized in that: The electrode is made of copper or aluminum; the electrode sheet is made of copper or aluminum; the metal column is made of any one of copper, aluminum and stainless steel; the metal core is made of any one of copper, aluminum and stainless steel; the cylinder is made of stainless steel or copper; and the end cover is made of stainless steel or copper.

10. A method for designing a high-frequency imaging sonar array structure according to any one of claims 1 to 9, characterized in that: The piezoelectric film is integrated with the circuit board, electrode, electrode sheet and circuit as the sensing element of the sonar array; The circuit board 1 is made of a whole PCB board, and holes distributed according to a specified rule are designed on the circuit board, and metal pillars are embedded in the holes; The piezoelectric film adopts a copolymer of difluoroethylene and trifluoroethylene piezoelectric film. The front and back sides of the piezoelectric film are coated with metal conductive electrodes. The piezoelectric film is pasted to the middle position of the circuit board using epoxy resin, and is tightly bonded to the metal column, so that the metal column and the metal conductive electrode are connected, and the metal column is used as the positive electrode of the piezoelectric film signal input; The electrodes are made of metal conductive material in the shape of strips, and the metal conductive material is copper or aluminum. The electrodes are embedded on the left and right sides of the circuit board 1, penetrate the circuit board, and serve as ground wires for the input of piezoelectric film signals. The electrode sheet is made of a metal conductive material such as copper or aluminum, and epoxy resin is used to bond and conduct the electrode sheet to the piezoelectric film and the electrode. The metal column is made of any metal material such as copper, aluminum, and stainless steel. The metal column is embedded in the hole of the circuit board, and the end face is flush with the outer surface of the circuit board and is tightly bonded to the piezoelectric film. It serves as a signal input and also as a hard backing for the piezoelectric film to reflect sound waves. The circuit is made of a preamplifier circuit and installed on the back of the circuit board. Each sensor element corresponds to a circuit, and the arrangement is consistent with the metal column. The circuit adopts a single-ended input and single-ended output method. All circuits share a ground wire and a power supply wire, and the ground wire is connected to the electrode.

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