阅读说明：本技术 一种密排中高频光纤水听器阵列及其制作方法 (Densely-arranged medium-high frequency optical fiber hydrophone array and manufacturing method thereof ) 是由 金梦群 王力求 葛辉良 魏培金 倪程辉 于 2021-09-06 设计创作，主要内容包括：本发明公开了一种密排中高频光纤水听器阵列及其制作方法,涉及水声光纤传感技术领域。本发明采用一体化思路,将传感结构、密封结构、阵列骨架和光组件等功能集合起来,最大限度地缩短轴向尺寸,实现阵元密排,同时绕线直径和内部盘纤空间增大,可靠性提高；通过优化设计增敏结构的材料和尺寸参数,并通过增加传感光纤长度等方法拓宽工作频带和提高灵敏度,测试得到的10-30kHz范围内灵敏度不小于-145dB。(The invention discloses a densely arranged medium-high frequency optical fiber hydrophone array and a manufacturing method thereof, relating to the technical field of underwater acoustic optical fiber sensing. The invention adopts an integrated thought, integrates the functions of a sensing structure, a sealing structure, an array framework, an optical assembly and the like, shortens the axial size to the maximum extent, realizes the dense arrangement of array elements, increases the winding diameter and the internal fiber coiling space, and improves the reliability; by optimally designing the material and the size parameter of the sensitization structure and increasing the length of the sensing optical fiber, the working frequency band is widened and the sensitivity is improved, and the sensitivity obtained by testing is not less than-145 dB within the range of 10-30 kHz.)

1. A densely arranged medium-high frequency fiber hydrophone array is characterized in that: comprises a plurality of hydrophone units (301), the hydrophone units (301) comprise hydrophone frameworks (102), the peripheries of the hydrophone frameworks (102) are tightly adhered with winding shells (101), an air cavity (108) is arranged between the winding shell (101) and the hydrophone framework (102), an optical component placing cavity (109) is arranged in the middle of the hydrophone framework (102) and used for placing an optical component box (103), hydrophone adapters (105) are arranged at two ends of the optical component box (103), an optical device (106) is arranged in the optical component box (103), a cover plate (104) is fixed at the upper part of the optical component box (103), a plurality of gaps (110) are formed in the cover plate (104) and used for leading out tail fibers of the optical device (106), the tail fibers led out by the optical device (106) are welded with the tail fibers in the optical component box (103) to form an optical path, and is led out through a fiber outlet hole (202) on the hydrophone adapter (105); optical fibers led out from fiber outlet holes (202) of all the hydrophone units (301) are sequentially connected through optical cables (302) to form a hydrophone string, a polyurethane sheath (303) is sleeved outside the hydrophone string, and fixing glue is filled in a gap between the hydrophone string and the polyurethane sheath (303) to form a hydrophone array.

2. The close-packed medium-high frequency fiber optic hydrophone array of claim 1, wherein: the winding shell (101) is formed by uniformly and densely winding a plurality of sensing optical fibers, and a polyurethane adhesive layer (107) is sleeved outside the winding shell (101) for sealing protection.

3. The close-packed medium-high frequency fiber optic hydrophone array of claim 1, wherein: a plurality of wiring holes (201) are formed in the hydrophone framework (102), and the wiring holes (201) are symmetrically distributed along the upper side and the lower side of the optical component box (103).

4. The close-packed medium-high frequency fiber optic hydrophone array of claim 1, wherein: a plurality of fixing holes (203) are formed in the side wall of the optical component box (103), and the fixing holes (203) are used for fixing the optical component box (103) and the hydrophone framework (102).

5. The close-packed medium-high frequency fiber optic hydrophone array of claim 1, wherein: the joint between the optical component box (103) and the hydrophone framework (102) is sealed through an O-shaped ring, and the joint between the optical component box (103) and the hydrophone adapter (105) is also sealed through the O-shaped ring.

6. The close-packed medium-high frequency fiber optic hydrophone array of claim 1, wherein: the cover plate (104) and the optical assembly box (103) are sealed and fixed through 705 glue.

7. The close-packed medium-high frequency fiber optic hydrophone array of claim 1, wherein: the optical device (106) is one or more of a wavelength division multiplexer, a coupler, and a rotating mirror.

8. A method for manufacturing a densely-arranged medium-high frequency fiber hydrophone array is characterized by comprising the following steps: the method comprises the following steps:

1) tightly bonding the winding shell (101) to the periphery of the hydrophone framework (102) by using epoxy glue, and standing at normal temperature for 24 hours for curing;

2) fixing the bonded winding shell (101) on a winding machine, uniformly and tightly winding the sensing optical fiber on the surface of the winding shell (101), and performing online control on tension and recording the length of the optical fiber during winding; after winding is finished, the sensing optical fiber is fixed by dispensing, and then the winding shell (101) is taken down from the winding machine;

3) brushing glue on the surface of the sensing optical fiber, fixing the winding shell (101) in a preheated pouring mold, putting the winding shell in an oven, and heating for 24 hours for curing;

4) dispensing and fixing an optical device (106) in an optical assembly box (103), leading out a tail fiber of the optical device (106) from a gap (110) of a cover plate (104), pouring glue from the gap (110) for curing after the cover plate (104) is fixed, welding the tail fiber led out of the optical device (106) and the tail fiber in the optical assembly box (103) to form a light path after curing, and leading out the light path outwards through a fiber outlet hole (202) on a hydrophone adapter (105);

5) the optical component box (103) is placed in the hydrophone framework (102), and joints between the optical component box (103) and the hydrophone framework (102) and between the optical component box (103) and the hydrophone adapter (105) are sealed by O-shaped rings, so that the hydrophone unit (301) is manufactured;

6) the fiber outlet holes (202) of the hydrophone units (301) are sequentially connected through optical cables (302) to form a hydrophone string, a polyurethane sheath (303) is sleeved outside the hydrophone string, and fixing glue is filled in a gap between the hydrophone string and the polyurethane sheath (303) to form a hydrophone array.

9. The method for manufacturing a closely-spaced medium-high frequency fiber optic hydrophone array according to claim 8, wherein the method comprises the following steps: and 3), brushing 301 glue on the surface of the sensing optical fiber, and slowly pouring polyurethane glue into the pouring mold.

10. The method for manufacturing a closely-spaced medium-high frequency fiber optic hydrophone array according to claim 8, wherein the method comprises the following steps: and 4), pouring 705 glue from the gap (110) for curing after the cover plate (104) is fixed.

Technical Field

The invention relates to the field of underwater acoustic optical fiber sensing technology, in particular to a closely-arranged medium-high frequency optical fiber hydrophone array and a manufacturing method thereof.

Background

The fiber hydrophone towed line array technology has become mature after the development of the last two decades, the current key technologies such as the array technology, the signal demodulation technology, the flow noise suppression technology and the like are basically broken through, and the reliability and the detection performance of the array are greatly improved.

The synthetic aperture sonar technology is to perform linear motion on a base array, sequentially transmit, receive and store signals, and then perform phase coherent superposition on echo signals stored at different times to obtain a virtual large-aperture base array narrow beam (high directivity or high resolution and high spatial gain). The traditional synthetic aperture sonar generally installs an acoustic array on a moving towed body, so that not only can the dense arrangement and routing of array elements be realized, but also the spacing of the array elements can be accurately controlled. If the synthetic aperture technology is combined with the towed line array technology, key technical problems of array cable arrangement, zero buoyancy design, high-frequency signal reception and the like must be solved.

The optical fiber hydrophone array has the characteristics of anti-electromagnetic interference at a wet end and easiness in multiplexing, so that the optical fiber towed line array technology applied to the synthetic aperture sonar has technical realizability.

The main working frequency band of the synthetic aperture sonar is in the order of tens kilohertz to hundreds kilohertz, so the array elements are usually densely arranged, and after the technical scheme of the towed line array is adopted, although a sparsely arranged mode can be adopted, the size of the hydrophone is still greatly limited, on the other hand, because the cables are densely arranged and the radial size is limited, the routing space is limited, and the like influence factors such as electromagnetic interference exist. The two points make the traditional piezoelectric towed line array technology difficult to meet the actual use requirement of the synthetic aperture sonar, so the advantages of easy multiplexing, electromagnetic interference resistance and the like can be fully exerted by adopting the fiber hydrophone towed line array technology; however, because the array elements are densely arranged, and the optical fiber hydrophone array devices and the welding points are many, the problems of sensitivity enhancement design, device placement, cable routing, zero buoyancy design and the like need to be mainly solved.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a close-packed medium-high frequency optical fiber hydrophone array and a manufacturing method thereof, which have the advantages of small size, good reliability and high sensitivity.

The purpose of the invention is achieved by the following technical scheme: a densely-arranged medium-high frequency optical fiber hydrophone array comprises a plurality of hydrophone units, wherein each hydrophone unit comprises a hydrophone framework, a winding shell is tightly adhered to the periphery of each hydrophone framework, an air cavity is arranged between each winding shell and each hydrophone framework, an optical component placing cavity is arranged in the middle of each hydrophone framework and used for placing an optical component box, hydrophone adapters are arranged at two ends of each optical component box, an optical component is arranged in each optical component box, a cover plate is fixed at the upper part of each optical component box, a plurality of gaps are formed in each cover plate and used for leading out tail fibers of each optical component, the tail fibers led out by the optical components are welded with the tail fibers in the optical component boxes to form a light path, and the light path is led out outwards through fiber outlet holes in the hydrophone adapters; optical fibers led out from fiber outlet holes of the hydrophone units are sequentially connected through optical cables to form a hydrophone string, a polyurethane sheath is sleeved outside the hydrophone string, and fixing glue is filled in a gap between the hydrophone string and the polyurethane sheath to form a hydrophone array.

As a further technical scheme, the winding shell is formed by uniformly and densely winding a plurality of sensing optical fibers, and a polyurethane adhesive layer is sleeved outside the winding shell for sealing protection.

As a further technical scheme, a plurality of wiring holes are formed in the hydrophone framework and used for penetrating optical cables, force bearing ropes and the like, and six wiring holes are symmetrically distributed along the upper side and the lower side of the optical component box.

As a further technical scheme, a plurality of fixing holes are formed in the side wall of the optical component box and used for fixing the optical component box and the hydrophone framework.

As a further technical scheme, the joint between the optical component box and the hydrophone framework is sealed through an O-shaped ring, and the joint between the optical component box and the hydrophone adapter is also sealed through the O-shaped ring.

As a further technical solution, the cover plate and the optical assembly box are sealed and fixed by 705 glue.

As a further technical scheme, the optical device is one or more of a wavelength division multiplexer, a coupler and a rotating mirror.

A method for manufacturing a densely-arranged medium-high frequency fiber hydrophone array comprises the following steps:

1) tightly bonding the winding shell to the periphery of the hydrophone framework by using epoxy glue, and standing at normal temperature for 24 hours for curing;

2) fixing the bonded winding shell on a winding machine, uniformly and tightly winding the sensing optical fiber on the surface of the winding shell, and performing online control on tension and recording the length of the optical fiber during winding; after winding is finished, the sensing optical fiber is fixed by glue dispensing, and then the winding shell is taken down from the winding machine;

3) brushing glue on the surface of the sensing optical fiber, fixing the winding shell in a preheated pouring mold, putting the winding shell in an oven, and heating for 24 hours for curing;

4) dispensing and fixing an optical device in an optical assembly box, leading out a tail fiber of the optical device from a gap of a cover plate, pouring glue from the gap for curing after the cover plate is fixed, welding the tail fiber led out by the optical device and the tail fiber in the optical assembly box to form a light path after curing, and leading out the tail fiber through a fiber outlet hole on a hydrophone adapter;

5) placing the optical component box into a hydrophone framework, and sealing joints between the optical component box and the hydrophone framework and between the optical component box and the hydrophone adapter by O-shaped rings to finish the manufacture of a hydrophone unit;

6) the fiber outlet holes of the hydrophone units are sequentially connected through optical cables to form a hydrophone string, a polyurethane sheath is sleeved outside the hydrophone string, and fixing glue is filled in a gap between the hydrophone string and the polyurethane sheath to form a hydrophone array.

As a further technical scheme, in step 3), a 301 glue is brushed on the surface of the sensing optical fiber, and a polyurethane glue is slowly poured into the pouring mold.

As a further technical scheme, in the step 4), 705 glue is poured from the gap for curing after the cover plate is fixed.

The invention has the beneficial effects that:

1. the hydrophone design scheme adopts an integrated thought, integrates functions of a sensing structure, a sealing structure, an array framework, an optical assembly and the like, shortens the axial size to the maximum extent, realizes the dense arrangement of array elements, increases the winding diameter and the internal fiber coiling space, and improves the reliability;

2. by optimally designing the material and the size parameter of the sensitization structure and increasing the length of the sensing optical fiber and other methods, the working frequency band is widened and the sensitivity is improved, a sensitivity frequency response curve in the range of 10-30kHz obtained by testing is shown in figure 5, and the sensitivity is not less than-145 dB.

Drawings

Fig. 1 is a schematic structural cross-section of a hydrophone unit.

Fig. 2 is a schematic structural view of the optical component case.

FIG. 3 is a side view of a hydrophone unit.

Fig. 4 is a schematic structural diagram of a hydrophone array.

FIG. 5 is a graph of the frequency response of the hydrophone sensitivity.

Description of reference numerals: the optical component cable comprises a winding shell 101, a hydrophone framework 102, an optical component box 103, a cover plate 104, a hydrophone adapter 105, an optical device 106, a polyurethane adhesive layer 107, an air cavity 108, an optical component placing cavity 109, a gap 110, a wiring hole 201, a fiber outlet hole 202, a fixing hole 203, a hydrophone unit 301, an optical cable 302 and a polyurethane sheath 303.

Detailed Description

The invention will be described in detail below with reference to the following drawings:

example (b): as shown in fig. 1 to 4, a densely-arranged medium-high frequency optical fiber hydrophone array includes a plurality of hydrophone units 301, each hydrophone unit 301 includes a hydrophone frame 102, the periphery of the hydrophone frame 102 is tightly bonded to a winding casing 101, an air cavity 108 is disposed between the winding casing 101 and the hydrophone frame 102, an optical component placing cavity 109 is disposed in the middle of the hydrophone frame 102 for placing an optical component box 103, hydrophone adapters 105 are disposed at both ends of the optical component box 103, an optical component 106 is disposed in the optical component box 103, a cover plate 104 is fixed on the upper portion of the optical component box 103 through 705 glue in a sealing manner, a plurality of gaps 110 are disposed on the cover plate 104 for leading out tail fibers of the optical component 106, the tail fibers led out by the optical component 106 are fused with the tail fibers in the optical component box 103 to form an optical path, and the optical path is led out through a fiber outlet hole 202 on the hydrophone adapter 105; optical fibers led out from the fiber outlet holes 202 of the hydrophone units 301 are sequentially connected through optical cables 302 to form a hydrophone string, a polyurethane sheath 303 is sleeved outside the hydrophone string, and fixing glue is filled in a gap between the hydrophone string and the polyurethane sheath 303 to form a hydrophone array.

Preferably, as shown in fig. 1, the winding casing 101 is made by winding a plurality of sensing optical fibers uniformly and densely, and a polyurethane glue layer 107 is sleeved outside the winding casing 101 for sealing protection. As shown in fig. 3, a plurality of wire holes 201 are formed in the hydrophone frame 102 for inserting optical cables, messenger wires, etc., and the six wire holes 201 are symmetrically distributed along the upper and lower sides of the optical module box 103. A plurality of fixing holes 203 are formed in the side wall of the optical component box 103, and the fixing holes 203 are used for fixing the optical component box 103 and the hydrophone framework 102. The joints between the optical component box 103 and the hydrophone frame 102 are sealed by O-rings, and the joints between the optical component box 103 and the hydrophone adapter 105 are also sealed by O-rings. The optical device 106 is one or more of a wavelength division multiplexer, a coupler, and a rotating mirror.

A method for manufacturing a densely-arranged medium-high frequency fiber hydrophone array comprises the following steps:

1) tightly bonding the winding shell 101 to the periphery of the hydrophone framework 102 by using epoxy glue, and standing at normal temperature for 24 hours for curing;

2) fixing the bonded winding shell 101 on a winding machine, uniformly and tightly winding the sensing optical fiber on the surface of the winding shell 101, and performing online control on tension and recording the length of the optical fiber during winding; after winding, the sensing optical fiber is fixed by glue dispensing, and then the winding shell 101 is taken down from the winding machine;

3) brushing 301 glue on the surface of the sensing optical fiber, fixing the winding shell 101 in a preheated pouring mold, slowly pouring polyurethane glue into the pouring mold, putting the pouring mold into an oven, and heating for 24 hours for curing;

4) dispensing and fixing the optical device 106 in the optical component box 103, then leading out the tail fiber of the optical device 106 from the gap 110 of the cover plate 104, pouring 705 glue from the gap 110 for curing after the cover plate 104 is fixed, welding the tail fiber led out by the optical device 106 and the tail fiber in the optical component box 103 to form a light path after curing, and leading out the light path through the fiber outlet hole 202 on the hydrophone adapter 105;

5) the optical component box 103 is placed in the hydrophone framework 102, and joints between the optical component box 103 and the hydrophone framework 102 and between the optical component box 103 and the hydrophone adapter 105 are sealed by O-rings, so that the hydrophone unit 301 is manufactured;

6) the fiber outlet holes 202 of the hydrophone units 301 are sequentially connected through optical cables 302 to form a hydrophone string, a polyurethane sheath 303 is sleeved outside the hydrophone string, and fixing glue is filled in a gap between the hydrophone string and the polyurethane sheath 303 to form a hydrophone array as shown in fig. 4.

The invention adopts an integrated thought, integrates the functions of a sensing structure, a sealing structure, an array framework, an optical assembly and the like, shortens the axial size to the maximum extent, realizes the dense arrangement of array elements, increases the winding diameter and the internal fiber coiling space, and improves the reliability; by optimally designing the material and the size parameter of the sensitization structure and increasing the length of the sensing optical fiber and other methods, the working frequency band is widened and the sensitivity is improved, a sensitivity frequency response curve in the range of 10-30kHz obtained by testing is shown in figure 5, and the sensitivity is not less than-145 dB.

It should be understood that equivalent substitutions and changes to the technical solution and the inventive concept of the present invention should be made by those skilled in the art to the protection scope of the appended claims.