Acceleration type optical fiber vector hydrophone combined with distributed sound wave sensing system

Abstract

The invention discloses an acceleration type optical fiber vector hydrophone combined with a distributed sound wave sensing system, and belongs to the technical field of underwater sound field acceleration measurement, the acceleration type optical fiber vector hydrophone comprises a mass block, the six surfaces of the mass block in the X-axis direction, the Y-axis direction and the Z-axis direction are all provided with elastic cylinders, and the outer end part of each elastic cylinder is connected with a metal cover; the three elastic cylinders in the X + direction, the Y + direction and the Z + direction of the mass block are sequentially wound through a first single-mode optical fiber, and the three elastic cylinders in the X-direction, the Y-direction and the Z-direction of the mass block are sequentially wound through a second single-mode optical fiber. According to the acceleration type optical fiber vector hydrophone combined with the distributed sound wave sensing system, the acceleration of underwater sound waves can be dynamically monitored in real time, the structure is simpler, an array is easy to form, and higher sensitivity and resolution are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of underwater sound field acceleration measurement, and in particular to an acceleration-type optical fiber vector hydrophone combined with a distributed sound wave sensing system. Background Art

[0002] In the prior art, with the advancement of science and technology, fiber optic hydrophones have shown very important application value in both military and civilian fields due to their advantages of high sensitivity and strong anti-electromagnetic interference ability. Fiber optic hydrophones can be divided into fiber optic scalar hydrophones and fiber optic vector hydrophones according to the different physical quantities detected. Fiber optic scalar hydrophones respond to scalar information of the sound field, such as sound pressure, and are not directional. In the application, multiple fiber optic sound pressure hydrophones are used to form a sensor array, and combined with the hydroacoustic signal processing algorithm, the target can be oriented. Fiber optic vector hydrophones respond to sound field vector information, such as sound field vibration velocity, acceleration, sound pressure gradient and displacement, etc., and the three-dimensional orientation of the target can be achieved by using multi-parameter joint signal processing methods.

[0003] At present, acceleration-type fiber optic vector hydrophones are all manufactured based on the Michelson interference principle. This structure requires multiple couplers and a fiber optic cable must be wound around each elastic cylinder to measure acceleration. The structure is relatively complex and difficult to form an array, and it is not capable of large-scale detection of underwater sound fields. Summary of the invention

[0004] The purpose of the present invention is to provide an acceleration-type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system, which can dynamically monitor the acceleration of underwater acoustic waves in real time, has a simpler structure, is easy to form an array, and has higher sensitivity and resolution.

[0005] To achieve the above-mentioned purpose, the present invention provides an acceleration-type fiber optic vector hydrophone combined with a distributed acoustic wave sensing system, comprising a mass block, wherein six surfaces of the mass block in the X-axis, Y-axis and Z-axis directions are installed with elastic cylinders, and the outer end of each elastic cylinder is connected to a metal cover; the three elastic cylinders in the X+, Y+ and Z+ directions of the mass block are sequentially wound with a first single-mode optical fiber, and the three elastic cylinders in the X-, Y- and Z- directions of the mass block are sequentially wound with a second single-mode optical fiber.

[0006] Preferably, grooves are provided at the connection positions between the mass block and the metal cover and the elastic column, and the size of the grooves is adapted to the elastic column.

[0007] Preferably, the elastic column, the mass block and the metal cover are fixed by waterproof sealant.

[0008] Preferably, the thickness of the elastic column is 0.1 mm to 5 mm.

[0009] Preferably, the preparation method is:

[0010] S1. Assemble the elastic column, mass block and metal cover with waterproof sealant;

[0011] S2, winding the first single-mode optical fiber and the second single-mode optical fiber evenly and tightly around elastic cylinders in different directions, and reserving additional optical fibers at both ends;

[0012] S3. Splice one end of the stripped and cut first single-mode optical fiber and one end of the second single-mode optical fiber to a jumper wire respectively, so as to connect them to the demodulation system.

[0013] Therefore, the beneficial effects of the present invention using the above-mentioned acceleration-type optical fiber vector hydrophone combined with the distributed acoustic wave sensing system are as follows:

[0014] (1) The present invention has low manufacturing cost and simple structure.

[0015] (2) The present invention has good sensitivity, high precision and can adapt to various harsh environments.

[0016] (3) The present invention only requires one single-mode optical fiber to complete the measurement, thereby reducing the complexity of manufacturing the hydrophone probe.

[0017] (4) The present invention is more convenient to form an array to measure the acceleration of a wide range of sound fields.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of an embodiment of an acceleration-type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system of the present invention;

[0020] Figure 2 It is a schematic structural diagram of a mass block of an embodiment of an acceleration-type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system of the present invention;

[0021] Figure 3 It is a structural schematic diagram of a metal cover of an embodiment of an acceleration-type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system of the present invention.

[0022] Reference numerals

[0023] 1. Mass block; 2. Elastic column; 3. Metal cover; 4. First single-mode optical fiber; 5. Second single-mode optical fiber; 6. Demodulation system. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] Embodiment 1

[0027] like Figure 1 As shown, the present invention provides an acceleration-type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system, including a mass block 1. The mass block 1 can be any shape that can connect three orthogonal directions, such as a sphere, a cube, etc. In this embodiment, the shape of the mass block 1 is a cube. The six faces of the mass block 1 in the X-axis, Y-axis, and Z-axis directions are all installed with elastic columns 2, and the outer end of each elastic column 2 is connected to a metal cover 3, wherein the thickness of the elastic column 2 is 0.1mm to 5mm.

[0028] like Figure 2 and Figure 3 As shown, grooves are provided at the connection positions of the mass block 1, the metal cover 3 and the elastic column 2, and the size of the grooves is adapted to the elastic column 2, and the mass block 1, the elastic column 2 and the metal cover 3 are better fixed. The elastic column 2, the mass block 1 and the metal cover 3 are fixed by waterproof sealant, which is convenient for further strengthening the stability of the connection between the three parts, so as to ensure that it can better adapt to the underwater environment, which is conducive to improving the service life of the fiber optic vector hydrophone.

[0029] In this embodiment, the three elastic cylinders 2 in the X+, Y+, and Z+ directions of the mass block 1 are each wound with a first single-mode optical fiber 4 in sequence, and the three elastic cylinders 2 in the X-, Y-, and Z- directions of the mass block 1 are each wound with a second single-mode optical fiber 5 in sequence, which can ensure that when the optical fiber vector hydrophone of this embodiment is working, two optical fibers simultaneously measure the underwater sound field. Among them, the types of the first single-mode optical fiber 4 and the second single-mode optical fiber 5 are not limited, as long as the loss of the optical fiber can be ignored after being wound on the elastic cylinder 2. In this embodiment, the first single-mode optical fiber 4 and the second single-mode optical fiber 5 are both anti-microbend optical fibers.

[0030] The manufacturing method of the optical fiber vector hydrophone of this embodiment is as follows:

[0031] S1. Assemble the elastic column 2, the mass block 1 and the metal cover 3 with waterproof sealant to form the basic structure of the fiber optic vector hydrophone.

[0032] S2. Wind the first single-mode optical fiber 4 and the second single-mode optical fiber 5 evenly and tightly on the elastic cylinder 2 in different directions, and reserve some optical fibers at both ends, and lead out the two ends of the optical fibers at the metal cover 3 of the x and z axes.

[0033] S3. The stripped and cut first single-mode optical fiber 4 and the second single-mode optical fiber 5 are each fused with a jumper wire for later connection with the demodulation system 6. Since the demodulation system 6 used in this embodiment is a prior art, it will not be described in detail here.

[0034] The working principle is:

[0035] When the fiber optic vector hydrophone is acted upon by an acceleration vector parallel to the axial direction of the elastic cylinder 2, due to the inertia of the mass block 1, the elastic cylinder 2 will be compressed or stretched in the axial direction, causing the elastic cylinder 2 to expand or contract in the radial direction, thereby causing the optical fiber wound on the elastic cylinder 2 to stretch or shorten, resulting in a phase change. The phase change caused by the acceleration in the sound field is then obtained through demodulation by the demodulation system 6, thereby realizing the measurement of the acceleration of the underwater sound field.

[0036] Therefore, the present invention adopts the above-mentioned acceleration-type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system, which can dynamically monitor the acceleration of underwater acoustic waves in real time, and has a simpler structure, is easy to form an array, and has higher sensitivity and resolution.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. An acceleration-type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system, characterized in that: It includes a mass block, wherein six faces of the mass block in the X-axis, Y-axis and Z-axis directions are installed with elastic columns, and the outer end of each elastic column is connected to a metal cover; the three elastic columns in the X+, Y+ and Z+ directions of the mass block are each wound in sequence with a first single-mode optical fiber, and the three elastic columns in the X-, Y- and Z- directions of the mass block are each wound in sequence with a second single-mode optical fiber.

2. The acceleration type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system according to claim 1, characterized in that: A groove is provided at the connection position between the mass block, the metal cover and the elastic column, and the size of the groove is adapted to the elastic column.

3. The acceleration type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system according to claim 1, characterized in that: The elastic column, the mass block and the metal cover are all fixed by waterproof sealant.

4. The acceleration type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system according to claim 1, characterized in that: The thickness of the elastic column is 0.1 mm to 5 mm.

5. The acceleration type optical fiber vector hydrophone combined with a distributed acoustic wave sensing system according to claim 1, characterized in that: Its production method is: S1. Assemble the elastic column, mass block and metal cover with waterproof sealant; S2, winding the first single-mode optical fiber and the second single-mode optical fiber evenly and tightly around elastic cylinders in different directions, and reserving additional optical fibers at both ends; S3. Splice one end of the stripped and cut first single-mode optical fiber and one end of the second single-mode optical fiber to a jumper wire respectively, so as to connect them to the demodulation system.

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