Receiving and transmitting shared vector receiving transducer

Abstract

The invention discloses a receiving and transmitting shared vector receiving transducer which comprises texture ceramic strips and electrode plates, and the multiple texture ceramic strips and the multiple electrode plates are alternately arranged and spliced into a cylinder. Every two texture ceramic strips form a group to form a pair of piezoelectric units, and the polarization directions of the two texture ceramic strips of each pair of piezoelectric units are opposite. The textured ceramic strip comprises a frame and textured ceramic particles, the frame is provided with a plurality of containing cavities which are separately arranged in the length direction of the frame, the containing cavities are filled with the textured ceramic particles, and the polarities of the textured ceramic particles in the containing cavities are the same; the electrode plates in the plurality of piezoelectric units are used as positive electrodes, and the electrode plates arranged between the adjacent piezoelectric units are used as negative electrodes; therefore, the combined application of the textured ceramic and the transducer is realized, and a new breakthrough is brought to the research of the transducer.

Description

Technical Field

[0001] The present invention relates to the technical field of transducers, and particularly to a vector receiving transducer for both transmitting and receiving. Background Art

[0002] Sound waves are currently the only information carriers that can propagate long distances in water. Underwater communication and detection mainly rely on sound waves, and the transmission and reception of underwater sound waves mainly rely on sonar transducers. Transducers are divided into transmitting transducers responsible for transmitting sound waves and hydrophones responsible for receiving sound waves. A transducer that has both transmitting and receiving functions is a transducer for both transmitting and receiving.

[0003] In the military field, unmanned systems are an important development direction for future battlefield weapons and equipment. As one of the key equipment for maritime military confrontation, underwater unmanned platforms have the ability to perform various types of complex tasks and are an important guarantee for winning underwater offensive and defensive battles. Among them, underwater unmanned small platforms have an important strategic position due to their small size, high flexibility, and rich functions. Underwater unmanned small platforms have relatively strict restrictions on the size of the equipment they carry. The transducers they carry need to have the characteristics of small size and flexible installation. However, traditional hydrophone arrays for receiving acoustic vector signals have disadvantages such as large volume and inconvenient installation.

[0004] A vector hydrophone can simultaneously obtain acoustic pressure scalar information and acoustic vector information such as particle velocity. A single vector hydrophone can achieve target signal detection and azimuth parameter estimation, and its directivity is independent of frequency, which can effectively suppress isotropic noise. It also has the characteristics of small volume and flexible deployment, and has great potential for application in underwater unmanned platforms. However, vector hydrophones also have problems such as insufficiently rich functions, insufficient differential pressure sensitivity, and insufficient sensitivity to higher-order acoustic information.

[0005] Cylindrical transducers have the characteristics of simple structure, low frequency, and small size. They can not only achieve low-frequency transmission functions but also achieve wide-band reception functions, and are widely used in the field of underwater acoustic transducers. When working as a transmitting transducer, the cylindrical transducer uses its breathing mode to work and has an omnidirectional characteristic; when working as a receiving hydrophone, the cylindrical transducer uses its low-frequency band far from the resonant frequency to work and has a flat acoustic pressure reception sensitivity.

[0006] Textured piezoelectric ceramics, abbreviated as textured ceramics, change the internal crystal orientation of piezoelectric ceramic materials through a specific process to make the ceramic grains oriented, so as to obtain piezoelectric coefficients and electromechanical coupling coefficients close to those of piezoelectric single crystals. Textured piezoelectric ceramics not only have a lower sound velocity than traditional piezoelectric ceramics PZT, but also the piezoelectric constant d 33 can reach up to more than 1000 at most, about 4 times that of PZT-4, and the piezoelectric coefficient g 33About twice that of PZT-4, a higher piezoelectric coefficient can bring better transceiver performance; longitudinal electromechanical coupling coefficient k 33 Reaches more than 0.8. A larger electromechanical coupling coefficient means that the textured ceramic material can theoretically achieve a wider working bandwidth and make the distance between the resonance frequency point and the anti-resonance frequency point farther, which is beneficial to simultaneously realizing the transmitting and receiving functions near the resonance point. The above performances of the textured ceramics are greatly improved compared with traditional PZT piezoelectric ceramics, making it have obvious theoretical performance advantages as a transceiver common vector receiving transducer. However, the textured ceramics currently have problems in the production process, such as large limitations on the preparation size and difficulty in making large-size particles.

[0007] Therefore, if the textured ceramics are combined with the transducer for application, it can obviously bring new breakthroughs to the research of the transducer. However, how to achieve this has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0008] The purpose of the present invention is to provide a transceiver common vector receiving transducer to solve the combined application of existing textured ceramics and transducers.

[0009] To solve the above technical problems, the present invention provides a transceiver common vector receiving transducer, which includes textured ceramic strips and electrode sheets. Multiple said textured ceramic strips and multiple said electrode sheets are alternately arranged and spliced into a cylindrical shape; every two of the textured ceramic strips form a group to form a pair of piezoelectric units, and the polarization directions of the two textured ceramic strips of each pair of piezoelectric units are opposite; the textured ceramic strip includes a frame and textured ceramic particles. The frame is provided with a plurality of receiving cavities separated along its length direction, and the plurality of receiving cavities are all filled with the textured ceramic particles, and the polarities of the textured ceramic particles in the plurality of receiving cavities are the same; the electrode sheets in the plurality of piezoelectric units are used as positive electrodes, and the electrode sheets arranged between adjacent piezoelectric units are used as negative electrodes.

[0010] In one embodiment, the frame is an epoxy frame.

[0011] In one embodiment, the electrode sheet is wedge-shaped.

[0012] In one embodiment, the transceiver common vector receiving transducer includes a sector column, a positive electrode wire and a negative electrode wire; each of the multiple sector columns includes a plurality of said piezoelectric units; each of the multiple sector columns is independently connected with the positive electrode wire, and in the same sector column, the positive electrode wire is connected to the positive electrodes of all the piezoelectric units; the negative electrodes of all the piezoelectric units are connected in parallel to the negative electrode wire.

[0013] In one embodiment, each of the multiple sector columns includes the same number of said piezoelectric units.

[0014] In one of the embodiments, when the transmitting-receiving common vector receiving transducer works as a transmitting transducer, the positive wires of the multi-petal sector columns are connected in parallel to a signal source of the transmitting-receiving common vector receiving transducer.

[0015] In one of the embodiments, when the transmitting and receiving shared vector receiving transducer works as an acoustic pressure hydrophone, the multi-petal sector columns are used to output acoustic pressure output signals after being connected in parallel.

[0016] In one embodiment, the number of the fan-shaped columns is four.

[0017] In one of the embodiments, when the transmit-receive shared vector receiving transducer is used as an acoustic vector receiving function, the positive wires of the multi-petal fan-shaped columns are connected in parallel to the signal source of the transmit-receive shared vector receiving transducer; each two opposing fan-shaped columns are regarded as a group, and the two petals of the fan-shaped columns in each group of the fan-shaped columns are used to output signals in a differential output manner.

[0018] The beneficial effects of the present invention are as follows:

[0019] Using textured ceramic material units instead of traditional piezoelectric material PZT as transducer material, the material has lower sound velocity and better piezoelectric performance, making the transducer work at a lower frequency and higher receiving sensitivity; using epoxy frame positioning to form textured ceramic strips with small-sized textured ceramic particles, the disadvantage of inconvenient production of large-sized textured ceramic particles is overcome. The design adopts tangential polarization mode to share the characteristics of small size and low frequency for both transmission and reception, and also takes advantage of the high longitudinal electromechanical coupling of ceramic particles to effectively improve the transmission voltage response and receiving sensitivity of the transducer; on the basis of taking into account the transmission and sound pressure receiving functions, the cylindrical transducer is split into petals to realize the vector receiving function in the x and y directions, which has richer functions and is conducive to the application on underwater unmanned small platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram provided by an embodiment of the present invention;

[0022] Figure 2 yes Figure 1 A schematic diagram of the structure of a piezoelectric unit viewed from above;

[0023] Figure 3 is Figure 1 the schematic top view structure of the sector column;

[0024] Figure 4 is Figure 1 the schematic frame structure;

[0025] Figure 5 is Figure 4 the schematic structure after filling with textured ceramic particles;

[0026] Figure 6 is Figure 5 the schematic structure after connection with the electrode sheet.

[0027] The reference numerals are as follows:

[0028] 10, textured ceramic strip; 11, frame; 111, receiving cavity; 12, textured ceramic particles;

[0029] 20, electrode sheet;

[0030] 30, piezoelectric unit;

[0031] 40, sector column;

[0032] 51, positive wire; 52, negative wire. Specific Embodiment

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] The present invention provides a transceiver - shared vector receiving transducer, and its embodiment is as Figures 1 to 6 shown, including a textured ceramic strip 10 and an electrode sheet 20. Multiple textured ceramic strips 10 and multiple electrode sheets 20 are alternately arranged and spliced into a cylindrical shape. For example, the vector receiving transducer in this embodiment includes 48 textured ceramic strips 10. Every two of the textured ceramic strips 10 form a group to form a pair of piezoelectric units 30, and the polarization directions of the two textured ceramic strips 10 in each pair of piezoelectric units 30 are opposite. The textured ceramic strip 10 includes a frame 11 and textured ceramic particles 12. The frame 11 is provided with a plurality of receiving cavities 111 separated along its length direction, and the plurality of receiving cavities 111 are all filled with textured ceramic particles 12, and the polarities of the textured ceramic particles 12 in the plurality of receiving cavities 111 are the same. The electrode sheets 20 in the plurality of piezoelectric units 30 are used as the positive electrodes, and the electrode sheets 20 arranged between adjacent piezoelectric units 30 are used as the negative electrodes.

[0035] Specifically, in this embodiment, the frame 11 is set as an epoxy frame. Therefore, in this embodiment, the textured ceramic particles 12 and the epoxy frame are used to form the tangentially polarized textured ceramic strip 10. Each textured ceramic strip 10 includes a strip-shaped epoxy frame and eight receiving cavities 111 for filling the textured ceramic particles 12; the polarization directions of the textured ceramic particles 12 in the eight receiving cavities are arranged in the same direction.

[0036] Among them, the electrode plates 20 in this embodiment are wedge-shaped, and the total number is 48.

[0037] As Figures 1 to 3 shown, in this embodiment, the transceiver shared vector receiving transducer is provided to include a fan-shaped column 40, a positive electrode wire 51, and a negative electrode wire 52; preferably, the number of fan-shaped columns 40 in this embodiment is four petals. Each of the multi-petal fan-shaped columns 40 includes a plurality of piezoelectric units 30. For example, there are 24 piezoelectric units 30 in this embodiment, and preferably, each of the multi-petal fan-shaped columns 40 includes the same number of piezoelectric units 30; each of the multi-petal fan-shaped columns 40 is independently connected to a positive electrode wire 51. In the same petal of the fan-shaped column 40, the positive electrode wire 51 is connected to the positive electrodes of all the piezoelectric units 30; the negative electrodes of all the piezoelectric units 30 are connected in parallel to the negative electrode wire 52.

[0038] Specifically, at this time, every two textured ceramic strips 10 form a group to form a pair of piezoelectric units 30. The polarization directions of the two textured ceramic strips 10 in each pair of piezoelectric units 30 are opposite, and the middle is connected by a wedge-shaped electrode plate 20, forming a total of 24 pairs of piezoelectric units 30. Among them, the electrode plate 20 sandwiched in the middle serves as the positive electrode and leads out the positive electrode wire 51. Each pair of piezoelectric units 30 is also connected by a wedge-shaped electrode plate 20. The adjacent piezoelectric units 30 share a wedge-shaped electrode plate 20. The shared wedge-shaped electrode plate 20 serves as the common negative electrode of the adjacent two piezoelectric units 30 and leads out the negative electrode wire 52. At this time, the transducer includes a total of 24 pairs of piezoelectric units 30.

[0039] Moreover, a complete transceiver shared vector receiving transducer is evenly divided into four fan-shaped columns 40 in the circumferential direction. Each fan-shaped column 40 includes six pairs of piezoelectric units 30. The positive electrode leads of all the piezoelectric units 30 in each petal of the fan-shaped column 40 are connected in parallel, and the negative electrodes of all the piezoelectric units 30 of the vector receiving transducer are connected in parallel. The transceiver shared vector receiving transducer leads out four positive electrode wires 51 and one negative electrode wire 52 in total.

[0040] Preferably, in this embodiment, when the transceiver shared vector receiving transducer operates as a transmitting transducer, the positive electrode wires 51 of the multi-petal fan-shaped columns 40 are connected in parallel to the signal source of the transceiver shared vector receiving transducer for omnidirectional transmission.

[0041] Preferably, in this embodiment, when the transceiver shared vector receiving transducer operates as a pressure hydrophone, the multi-lobe fan-shaped columns 40 are used to output a sound pressure output signal in parallel for omnidirectional reception.

[0042] Preferably, in this embodiment, when the transceiver shared vector receiving transducer is used as a sound vector receiving function, the positive wire 51 of the multi-lobe fan-shaped columns 40 is connected in parallel to the signal source of the transceiver shared vector receiving transducer; every two opposite fan-shaped columns 40 form a group, and the two fan-shaped columns 40 in each group of fan-shaped columns 40 are used to output signals in a differential output manner.

[0043] That is, the transceiver shared vector receiving transducer can use two opposite (non-adjacent) fan-shaped columns 40 as a group, which are divided into two groups in total, and respectively form the orthogonal x and y directions of the vector transducer. The output signals of the two fan-shaped columns 40 in each group are subtracted and then output, and the sound vector receiving function in the horizontal direction is realized by using the pressure difference method.

[0044] The working mechanism of the transceiver shared vector receiving transducer is analyzed as follows:

[0045] The cylindrical pressure difference type vector hydrophone cannot directly measure the sound vector information. It mainly based on the finite difference approximation principle, and performs finite difference processing on the sound pressure difference and distance difference between two points or multiple points in the sound field, and obtains the sound vector information at the center of the pressure difference type hydrophone through cross calculation between two points or multiple points. Compared with the traditional pressure hydrophone that can only measure the scalar sound pressure, the pressure difference information measured by the pressure difference type vector hydrophone itself has a certain directivity and can suppress isotropic noise to a certain extent.

[0046] The working principle of the pressure difference type vector hydrophone is based on the Taylor series expansion. Taking a point r=(x 0 ,y 0 ) on the xoy plane in the two-dimensional space as an example, the Taylor expansion of the sound pressure at this point is performed, and the obtained formula (1) is obtained. For the convenience of explanation, only the second-order term is expanded and the higher-order infinitesimal terms are ignored.

[0047]

[0048] For a differential unit at a certain place in the sound field, according to Newton's second law, it can be obtained that:

[0049]

[0050] Among them, V=[v x ,v y represents the particle vibration velocity, v x ,v y represent the orthogonal components of the particle vibration velocity on the X-axis and Y-axis respectively, ρ represents the medium density, Denotes the gradient operation. The left side of the equation is the negative gradient of the sound pressure, representing the force acting on the differential element, and the right side of the equation represents the acceleration generated by the differential element under the action of the force.

[0051] Considering a harmonic plane wave, the time function of the sound wave is exp(jωt). Substituting it into Equation (2), we get:

[0052]

[0053] where ω represents the angular velocity of the plane wave. Substituting Equation (3) into Equation (1), we get:

[0054]

[0055] It can be seen from the above equation that each term after the Taylor series expansion of the sound pressure is related to different physical quantities in the sound field. The first term is the 0th-order term of the sound pressure, which is equal to the sound pressure. The second term is the 1st-order term, which is proportional to the particle velocity. The third term is the 2nd-order term, which is proportional to the change in the instantaneous density of the sound field.

[0056] Next, consider the plane wave sound field. The sound pressure function of the harmonic plane wave can be expressed as:

[0057] p(r,t) = pe j(ωt-kcosθ·x-ksinθ·y) #(5)

[0058] Substituting the above equation into Equation (1), we can obtain the sound pressure terms of each order. Among them, the 1st-order term of the sound pressure can be expressed as:

[0059]

[0060] Taking the Taylor series expansion of a microelement at a certain point in the two-dimensional sound field along the X-axis direction as an example, the relationship between the sensitivities of different-order acoustic quantities is analyzed. First, substitute Equations (5), (6), and (8) into Equation (1) respectively, and let x 0 = 0, we get:

[0061] p(x,t) = p 0 e jωt -jkcosθ·xp 0 e jωt #(8)

[0062] Let α = kxcosθ, then the 0th-order term and the 1st-order term of the sound pressure can be expressed as:

[0063] |p(x,t)| = p 0 #(9)

[0064] |p 1 (x,t)| = αp 0 #(10)

[0065] The conversion relationships between the various orders of quantities in the simple harmonic sound field are analyzed below. Substituting equation (5) into equation (3) gives the following multiple relational expressions:

[0066]

[0067] Let the acceleration of the particle velocity be After substituting into the above equations, the following relational expressions can be obtained:

[0068]

[0069] For different acoustic quantities and different measurement methods, there will be certain differences in the sensitivities of the acoustic quantities of each order. Combining equations (5) to (11) and equations (16) to (25), with the sound pressure sensitivity as the reference and letting θ = 0, the relationships of the sensitivities of the differential pressure vector hydrophone on the x-axis are as follows:

[0070]

[0071] Where M p represents the sound pressure sensitivity, V represents the measured voltage, M p' represents the sound pressure gradient sensitivity, M v represents the particle velocity sensitivity, M a represents the acceleration sensitivity, M p” represents the second-order sound pressure gradient sensitivity, M v' represents the particle velocity gradient sensitivity, M a' represents the acceleration gradient sensitivity.

[0072] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A transmitting and receiving common vector receiving transducer, characterized in that: It comprises a textured ceramic strip and an electrode sheet, wherein a plurality of the textured ceramic strips and a plurality of the electrode sheets are alternately arranged and spliced ​​into a cylindrical shape; The textured ceramic strips are grouped into two to form a pair of piezoelectric units, and the polarization directions of the two textured ceramic strips of each pair of piezoelectric units are opposite; the textured ceramic strips include a frame and textured ceramic particles, the frame is provided with a plurality of receiving cavities separated and arranged along its length direction, the plurality of receiving cavities are filled with the textured ceramic particles, and the polarities of the textured ceramic particles in the plurality of receiving cavities are the same; The electrode sheets in the plurality of piezoelectric units are used as positive electrodes, and the electrode sheets provided between adjacent piezoelectric units are used as negative electrodes.

2. The transmitting and receiving shared vector receiving transducer according to claim 1, characterized in that: The frame is an epoxy frame.

3. The transmitting and receiving shared vector receiving transducer according to claim 1, characterized in that: The electrode sheet is wedge-shaped.

4. The transmitting and receiving shared vector receiving transducer according to claim 1, characterized in that: The transmitting and receiving shared vector receiving transducer comprises a fan-shaped column, a positive wire and a negative wire; The multi-petal sector-shaped columns each include a plurality of the piezoelectric units; The multi-petal sector columns are all independently connected to the positive electrode wire, and in the same petal sector column, the positive electrode wire is connected to the positive electrodes of all the piezoelectric units; The negative electrodes of all the piezoelectric units are connected in parallel to the negative electrode wire.

5. The transmitting and receiving shared vector receiving transducer according to claim 4, characterized in that: The multi-petal sector-shaped columns all include the same number of piezoelectric units.

6. The transmitting and receiving shared vector receiving transducer according to any one of claims 4 or 5, characterized in that: When the transmitting-receiving common vector receiving transducer works as a transmitting transducer, the positive wires of the multi-petal sector columns are connected in parallel to a signal source of the transmitting-receiving common vector receiving transducer.

7. The transmitting and receiving shared vector receiving transducer according to any one of claims 4 or 5, characterized in that: When the transmitting and receiving common vector receiving transducer works as an acoustic pressure hydrophone, the multi-petal sector-shaped columns are used to output acoustic pressure output signals after being connected in parallel.

8. The transmitting and receiving shared vector receiving transducer according to any one of claims 4 or 5, characterized in that: The number of the fan-shaped column is four.

9. The transmitting and receiving shared vector receiving transducer according to claim 8, characterized in that: When the transmitting-receiving common vector receiving transducer is used as an acoustic vector receiving function, the positive wire of the multi-petal sector column is connected in parallel to the signal source of the transmitting-receiving common vector receiving transducer; Each two opposite sector-shaped columns form a group, and the two sector-shaped columns in each group of sector-shaped columns are used to output signals in a differential output manner.

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