A method for designing high-frequency imaging sonar array

Abstract

The present invention relates to a method for designing a high-frequency imaging sonar array, which uses a piezoelectric polymer film with a regionalized piezoelectric performance, a preamplifier circuit, an electrode structure, and a support structure in an integrated design; wherein the electrode structure includes an electrode and an electrode sheet; the support structure includes a cylinder and an end cap; the circuit board is made of a whole PCB board, a predetermined number of holes are distributed on the circuit board, and electrodes are embedded in the corners of one side of the circuit board. The present invention effectively avoids the design drawbacks based on the traditional piezoelectric ceramic sonar array, and at the same time, the non-sensing part of the polymer film does not participate in the pickup of the acoustic signal, avoiding the crosstalk of the lateral mode in the operation of the hydrophone.

Description

Technical Field

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

[0002] Imaging sonar is an electronic device that uses sound waves to detect and image underwater targets. It is based on the propagation and reflection characteristics of sound waves in water, and through electroacoustic conversion and information processing, it can detect, classify, locate and track underwater targets.

[0003] Existing technology is limited by the fact 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 sensors cannot ensure the performance consistency of each element. The regionalized design of piezoelectric performance and the integrated design of acquisition circuits, hydrophone structures and sensor elements are difficult, making it 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 method for designing a high-frequency imaging sonar array, which effectively avoids the design drawbacks of traditional piezoelectric ceramic sonar arrays. At the same time, the non-sensing part of the polymer film does not participate in the pickup of the acoustic signal, thus avoiding the crosstalk of the lateral mode during the operation of the hydrophone.

[0005] The technical solution of the present invention is to provide a method for designing a high-frequency imaging sonar array, which uses a piezoelectric polymer film with regionalized piezoelectric performance and an integrated design with a preamplifier circuit, an electrode structure, and a support structure; wherein:

[0006] The electrode structure includes an electrode and an electrode sheet; the supporting structure includes a cylinder and an end cap;

[0007] The circuit board is made of a whole PCB board, a predetermined number of holes are distributed on the circuit board, and electrodes are embedded in the corners of one side of the circuit board;

[0008] 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 side of the piezoelectric film is covered with a conductive electrode, and the back side is not provided with a conductive electrode. The piezoelectric performance of the piezoelectric film is achieved by the following regional design. A plurality of circular polarization regions arranged at intervals are formed on the piezoelectric film by polarization, so that only the circular polarization region of the piezoelectric film has piezoelectric performance and performs acoustic sensing, and a single circular polarization region is an acoustic array sensor element. Each circular polarization region corresponds to the installation position of the metal sheet on the circuit board one by one, and the remaining regions of the piezoelectric film have no sensing performance. At the same time, the piezoelectric film is pasted on the circuit board by epoxy resin;

[0009] The electrode sheet is made of metal conductive material into a thin sheet, and epoxy resin is used to bond and conduct the electrode sheet with the conductive electrode and electrode on the front side of the piezoelectric film;

[0010] The electrode is made of metal conductive material into a cylinder. The electrode runs through the circuit board and serves as the ground wire for the piezoelectric film signal input. At the same time, it is connected to the cylinder, so that the entire outer surface of the hydrophone is connected to the ground wire.

[0011] The metal sheet is made of metal material, embedded in the hole of the circuit board, with its surface flush with the outer surface of the circuit board, and tightly bonded to the piezoelectric film, serving as the positive input of the signal; the cross section of the metal sheet is the same as the sensing area of ​​a single sensing element;

[0012] The preamplifier circuit is installed on the back of the circuit board. Each sensor element corresponds to a preamplifier circuit. The preamplifier circuit is close to the sensor element. The preamplifier circuit adopts a single-ended input and single-ended output mode. All preamplifier circuits share a ground wire and a power supply wire, and the ground wire is connected to the electrode.

[0013] The wiring board adopts a close-packed design of jacks, and the signal output lines of all sensor primitives are gathered on the wiring board;

[0014] The metal core is made of conductive metal material, with an outer diameter of no more than 0.6 mm, much smaller than the metal sheet. The metal core is embedded in the metal sheet and runs through the circuit board to effectively connect the electrical signal of the sensor element with the circuit without affecting the miniaturization design of the circuit.

[0015] The plug adopts a pin-type close-packed design. The plug has a multi-core cable and is connected to the wiring board. The electrical signal amplified by each sensor element is gathered to the connector through the cable.

[0016] The perfusion layer is used to make the outermost sensing surface watertight;

[0017] The cylinder is made of metal material and serves as the pressure-resistant shell of the sound array, and is connected to the ground wire of the preamplifier circuit;

[0018] The end cover is made of metal material, and an O-ring groove is designed on the outer periphery of the end cover. An O-ring is embedded in the O-ring groove. The end cover and the cylinder are watertightly matched. There is a hole in the center of the end cover for installing the connector.

[0019] The connector is installed in the hole of the end cover for signal transmission and watertightness.

[0020] The present invention comprehensively considers sensing materials, regional performance design, electromagnetic shielding design, structural design, and acquisition circuit design, and effectively solves the design difficulties of the prior art.

[0021] Preferably, the front side of the film is coated with a conductive electrode coating.

[0022] Preferably, the circular polarization regions are evenly distributed on the piezoelectric film.

[0023] Preferably, the cross-section of the metal sheet is the same as the sensing area of ​​a single sensing element.

[0024] Preferably, epoxy resin is used to bond and connect the electrode sheet to the front conductive electrode and electrode of the piezoelectric film.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The present invention adopts the idea of ​​integrated design of piezoelectric film with regional performance design and preamplifier circuit, electrode structure and supporting structure, which can effectively improve the sensing area and sensing signal quality of the sonar array, improve the sensitivity of the sensing element and the performance consistency of the element, the array layout can be flexibly adjusted, the working frequency band can be adapted to a wide range, and the sensing element has the advantages of pure working mode, impact resistance, and stable performance under high hydrostatic pressure. The research and 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

[0027] Figure 1 It is a schematic diagram of the local structure of an embodiment of the present invention.

[0028] Figure 2 Schematic diagram of the front and back sides of the piezoelectric film of the present invention.

[0029] Figure 3 Schematic diagram of the polarization region of the piezoelectric film according to an embodiment of the present invention.

[0030] Figure 4 The figure is a schematic diagram of the structure of a preamplifier circuit and a circuit board according to an embodiment of the present invention.

[0031] Figure 5 for Figure 4 Side view of.

[0032] Figure 6 It is a schematic diagram of the local structure of an embodiment of the present invention.

[0033] Figure 7 It is an exploded view of an embodiment of the present invention.

[0034] Figure 8 It is a schematic structural diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the accompanying drawings:

[0036] The present invention provides a method for designing a high-frequency imaging sonar array. Figure 1-8 As shown, the high-frequency imaging sonar array structure of the present invention mainly includes a circuit board 1, a piezoelectric film 2, an electrode sheet 3, an electrode 4, a metal sheet 5, a preamplifier circuit 6, a wiring board 7, a metal core 8, a plug 9, a perfusion layer 10, a cylinder 11, an end cover 12, and a connector 13. When designing the array, the piezoelectric film 2 with a regionalized piezoelectric performance is integrated with the preamplifier circuit 6, the electrode structure, and the support structure; wherein,

[0037] The piezoelectric film 2 is made of polyvinylidene fluoride (PVDF) piezoelectric film or a copolymer of difluoroethylene and trifluoroethylene P (VDF-TrFE) piezoelectric film. 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 side of the piezoelectric film 2 is coated with a conductive electrode coating (such as Figure 2 ), there is no conductive electrode on the reverse side, and the piezoelectric performance of the piezoelectric film 2 is achieved by the following regional design. A plurality of circular polarization regions 21 arranged at intervals are formed on the piezoelectric film 2 by polarization, so that only the circular polarization region 21 on the piezoelectric film 2 has piezoelectric performance and performs acoustic sensing, and a single circular polarization region 21 is an acoustic array sensor element; in this embodiment, the circular polarization regions 21 are evenly distributed on the piezoelectric film 2, such as Figure 3 shown.

[0038] like Figure 1 As shown, the electrode structure includes an electrode 4 and an electrode sheet 3; Figure 7 As shown, the support structure includes a cylinder 11 and an end cover 12;

[0039] The circuit board 1 is made of a whole PCB board, and the piezoelectric film 2 is pasted on the circuit board 1 with epoxy resin. A predetermined number of holes are distributed on the circuit board 1, and the hole distribution method is the same as the array method of the sensing element. A metal sheet 5 is embedded in the hole, and the metal sheet can be made of metal materials such as copper, aluminum, and stainless steel. The metal sheet 5 is flush with the outer surface of the circuit board 1 and is tightly bonded to the piezoelectric film 2 as a signal positive input. Each circular polarization area 21 of the piezoelectric film 2 corresponds to the position of the metal sheet 5 on the circuit board 1; the remaining unpolarized areas of the piezoelectric film 2 have no sensing performance; in this embodiment, the cross-section of the metal sheet 5 is the same as the sensing area of ​​a single sensing element, and the same distribution method of the two determines the array method of the hydrophone array, so the array method of the acoustic array can be flexibly designed according to the use requirements for the distribution of the piezoelectric film 2 and the metal sheet 5;

[0040] The electrode sheet 3 is made of a metal conductive material, such as copper, aluminum and other metal materials. The electrode sheet 3 is electrically connected to the conductive electrode of the piezoelectric film 2 and the electrode 4;

[0041] The electrode 4 is made of metal conductive material into a cylindrical shape, such as copper, aluminum and other metal materials. The electrode 4 is embedded in the lower left corner of the circuit board 1. The electrode 4 runs through the circuit board 1 and serves as the ground wire for the piezoelectric film signal input. At the same time, it is connected to the cylinder 10, and the entire outer surface of the hydrophone is connected to the ground wire.

[0042] The preamplifier circuit 6 is installed on the back of the circuit board 1. Each sensor element corresponds to a preamplifier circuit 6. The preamplifier circuit 6 is close to the sensor element. The preamplifier circuit adopts a single-ended input and single-ended output mode. All preamplifier circuits 6 share a ground wire and a power supply wire. The ground wire is connected to the electrode 4.

[0043] The cylinder 11 is made of metal materials, such as stainless steel, copper and other metal materials, and serves as a pressure-resistant shell of the sound array and is connected to the ground wire of the preamplifier circuit 6; the end cover 12 is made of metal materials, and the end cover 12 is watertightly matched with the cylinder 10.

[0044] In this embodiment, Figure 4 , 6 As shown in , 7, the wiring board 7 adopts a jack-type close-packed design, and the signal output lines of all sensor elements are gathered on the wiring board 7. The plug 9 adopts a pin-type close-packed design. The plug 9 has a multi-core cable and is connected to the wiring board 7. The electrical signal amplified by each sensor element is gathered to the connector 13 through the cable line; the end cover 11 is provided with a hole, and the connector 13 is installed in the hole of the end cover 11 for signal transmission and watertightness; the pouring layer 12 is used for watertightness of the outermost sensing surface, and the pouring layer 10 is poured with polyurethane or epoxy resin. In this embodiment, the end cover 12 is made of metal materials, such as stainless steel, copper and other metal materials.

[0045] As a preferred method, Figure 5 As shown, a metal core 8 is also embedded on the metal sheet 5. The metal core 8 runs through the circuit board 1 and is used to effectively connect the electrical signal of the sensor element with the preamplifier circuit 6. The metal core 8 is made of conductive metal materials, such as copper, aluminum, stainless steel and other metal materials. Copper is used in this embodiment, and the outer diameter is smaller than the size of the metal sheet 5.

[0046] 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 method for designing a high-frequency imaging sonar array, characterized in that: The piezoelectric film with regionalized piezoelectric performance is integrated with the preamplifier circuit, electrode structure and support structure; The piezoelectric film adopts a polyvinylidene fluoride (PVDF) piezoelectric film or a copolymer of difluoroethylene and trifluoroethylene P (VDF-TrFE) piezoelectric film. The front side of the piezoelectric film is covered with a conductive electrode, and the back side has no conductive electrode. The piezoelectric performance of the piezoelectric film is achieved by the following regional design. A plurality of circular polarization regions arranged at intervals are formed on the piezoelectric film by polarization, so that only the circular polarization region of the piezoelectric film has piezoelectric performance and performs acoustic sensing, and a single circular polarization region is an acoustic array sensor element. The electrode structure includes an electrode and an electrode sheet; The circuit board is made of a whole PCB board, and the piezoelectric film is pasted on the circuit board. A predetermined number of holes are distributed on the circuit board, and metal sheets are embedded in the holes. The metal sheets are flush with the outer surface of the circuit board and are tightly bonded to the piezoelectric film as the positive input of the signal. Each circular polarization area of ​​the piezoelectric film corresponds to the position of the metal sheet on the circuit board. A metal core is also embedded on the metal sheet, which runs through the circuit board to effectively connect the electrical signal of the sensing element with the circuit. The electrode sheet is made of a metal conductive material into a thin sheet, and the electrode sheet is connected to the conductive electrode and the electrode of the piezoelectric film; The electrode is made of metal conductive material, and is embedded on one side of the circuit board. The electrode runs through the circuit board and serves as a ground wire for the piezoelectric film signal input. The preamplifier circuit is installed on the back of the circuit board. Each sensing element corresponds to a preamplifier circuit. All preamplifier circuits share a ground wire and a power supply wire, and the ground wire is connected to the electrode.

2. The method for designing a high-frequency imaging sonar array according to claim 1, characterized in that: The front side of the film is coated with a conductive electrode coating.

3. The method for designing a high-frequency imaging sonar array according to claim 1, characterized in that: The circular polarization areas are evenly distributed on the piezoelectric film.

4. The method for designing a high-frequency imaging sonar array according to claim 1, characterized in that: The cross-section of the metal sheet is the same as the sensing area of ​​a single sensing element.

5. The method for designing a high-frequency imaging sonar array according to claim 1, characterized in that: The electrode sheet is bonded and connected to the front conductive electrode and the electrode of the piezoelectric film by using epoxy resin.

6. The method for designing a high-frequency imaging sonar array according to claim 1, characterized in that: A terminal board is provided on the high-frequency imaging sonar array. The terminal board adopts a close-packed jack design, and the signal output lines of all sensor elements are converged on the terminal board.

7. The method for designing a high-frequency imaging sonar array according to claim 1, characterized in that: The metal core is made of conductive metal material, and its outer diameter is smaller than that of the metal sheet.

8. The method for designing a high-frequency imaging sonar array according to claim 1, characterized in that: The supporting structure includes a cylinder and an end cover. The cylinder is made of metal material and serves as the pressure-resistant shell of the acoustic array and is connected to the ground wire of the preamplifier circuit. The end cover is made of metal material and is watertightly matched with the cylinder. The electrode is connected to the cylinder, and the entire outer surface of the hydrophone is connected to the ground wire.

9. The method for designing a high-frequency imaging sonar array according to claim 8, characterized in that: The high-frequency imaging sonar array is also equipped with a plug, a perfusion layer, and a connector. The plug adopts a close-packed pin design and has a multi-core cable, which is connected to the terminal board to converge the electrical signal amplified by each sensor element to the connector through the cable. Holes are opened on the end cover, and the connectors are installed in the holes of the end cover for signal transmission and watertightness. The perfusion layer is used for watertightness of the outermost sensing surface.

10. The method for designing a high-frequency imaging sonar array according to claim 9, characterized in that: An O-ring groove is arranged on the outer diameter of the end cover, an O-ring is embedded in the groove, and the end cover is tightly installed inside the cylinder to be watertight.

Images