Underwater seismic wave detection three-dimensional induction device, induction method and manufacturing method

Abstract

The invention discloses an underwater seismic wave detection three-dimensional induction device, an induction method and a manufacturing method, and belongs to the field of underwater seismic wave detection.The underwater seismic wave detection three-dimensional induction device comprises an upper end cover and a lower end cover which are connected with each other, and a spherical cavity is formed in a sphere formed by the upper end cover and the lower end cover; a plurality of magnets and a suspension mass block which interact with each other are arranged in the spherical cavity, an optical fiber bundle is arranged on a sphere formed by the upper end cover and the lower end cover, the bottom end of the optical fiber bundle extends into the suspension mass block, and the bottom end of the optical fiber bundle is an axially-arranged optical fiber end face. The three-dimensional sensing device can dynamically monitor vibration signals of underwater seismic waves in real time, is simpler in structure, can measure three dimensions, and has higher sensitivity and resolution.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater seismic wave detection, and in particular to a three-dimensional sensing device, a sensing method and a manufacturing method for underwater seismic wave detection. Background Art

[0002] The development of optical fiber vibration sensors is changing with each passing day, and their application prospects in industrial monitoring, structural health monitoring, environmental monitoring and other fields are very broad. Optical fiber vibration sensors are of great significance in underwater seismic wave detection. By providing high-precision, anti-interference, and long-term stable monitoring methods, they help improve the scientificity and operability of marine earthquake research, seabed resource exploration, marine engineering safety, and disaster warning.

[0003] Existing optical fiber vibration sensors usually have complex internal structures and are difficult to produce. They are unable to dynamically monitor underwater seismic wave vibration signals in real time and cannot measure in three dimensions. In view of this, a three-dimensional vibration sensor for underwater seismic wave detection based on Fabry-Perot interferometry theory is proposed. Summary of the invention

[0004] The purpose of the present invention is to provide a three-dimensional sensing device, sensing method and manufacturing method for underwater seismic wave detection, which can dynamically monitor the vibration signals of underwater seismic waves in real time, has a simpler structure, can measure three dimensions, and has higher sensitivity and resolution.

[0005] To achieve the above-mentioned purpose, the present invention provides a three-dimensional sensing device for underwater seismic wave detection, comprising an upper end cover and a lower end cover connected to each other, a spherical cavity is arranged inside the sphere composed of the upper end cover and the lower end cover, a plurality of interacting magnets and a suspended mass block are arranged inside the spherical cavity, an optical fiber bundle is arranged on the sphere composed of the upper end cover and the lower end cover, the bottom end of the optical fiber bundle extends into the suspended mass block, and the bottom end of the optical fiber bundle is an axially arranged optical fiber end face.

[0006] Preferably, the suspended mass block is located at the center of the spherical cavity, the magnets are distributed at the center positions of the front, rear, left, right and bottom sides of the suspended mass block, and the magnets are arranged on the inner wall of the spherical cavity.

[0007] Preferably, an opening is provided on the upper end cover, and the optical fiber bundle is located in the opening.

[0008] Preferably, the optical fiber bundle includes three single-mode optical fibers, and the bottom end of each single-mode optical fiber corresponds to a fiber end face.

[0009] Preferably, a three-dimensional spatial coordinate is established with the center of the spherical cavity as the origin, two mutually perpendicular axes on the axial plane formed by the centers of the magnets distributed at the front, rear, left and right positions of the suspended mass block as the x-axis and y-axis, and the direction perpendicular to the axial plane as the z-axis. The directions in which the three optical fiber end faces are arranged are the axial directions of the three axes of the three-dimensional spatial coordinate.

[0010] Preferably, three surfaces on the inner wall of the suspended mass block corresponding to the three optical fiber end faces are test surfaces, and the three test surfaces of the suspended mass block and the three optical fiber end faces are all coated with high reflectivity films, and a Fabry-Perot interference cavity is formed between the test surfaces and the corresponding optical fiber end faces.

[0011] Preferably, the suspended mass block is a hollow shell and is made of magnetic material.

[0012] Preferably, the upper end cover and the lower end cover are fixed by a locking element, and both the upper end cover and the lower end cover are provided with a fixing plate, the fixing plate is provided with a fixing hole, and the locking element is arranged in the fixing hole.

[0013] The present invention provides a method for manufacturing a three-dimensional sensing device for underwater seismic wave detection, comprising the following steps: Step 1: coat the three test surfaces and three optical fiber end faces inside the suspended mass block with a high reflectivity film, and fix all five magnets at the center of the required surface of the spherical cavity; Step 2: Place the suspended mass block at the center of the spherical cavity, and control the distance between the three test surfaces inside the suspended mass block and the end face of the optical fiber, and fix the upper end cover, the lower end cover and the optical fiber bundle accordingly; Step three, the stripped and cut single-mode optical fiber is fused with the jumper, and then connected to the demodulation system to measure the acoustic field vibration signal.

[0014] The present invention provides a sensing method for a three-dimensional sensing device for underwater seismic wave detection, comprising the following steps: When the three-dimensional sensing device is subjected to a vibration signal parallel to the axial direction of the suspended mass block, the suspended mass block will be offset in the axial direction due to the inertia of the suspended mass block, causing the length of the Fabry-Perot interference cavity inside the suspended mass block to increase or decrease in the radial direction, resulting in a phase change. The phase change caused by the vibration in the sound field is obtained by demodulation, thereby realizing the measurement of the underwater sound field vibration signal.

[0015] Therefore, the present invention adopts the above-mentioned structure of the underwater seismic wave detection three-dimensional sensing device, sensing method and manufacturing method, which has the following beneficial effects: (1) The three-dimensional sensing device of the present invention achieves three-dimensional measurement of underwater sound field vibration signals by arranging magnets and suspended mass blocks inside a spherical body composed of an upper end cover and a lower end cover. The overall structure is simple, the manufacturing cost is low, and it is easy to produce. (2) The three-dimensional sensing device of the present invention realizes the measurement of underwater acoustic field vibration signals through a Fabry-Perot interferometer cavity, has good sensitivity, high precision and can adapt to various harsh environments; (3) The three-dimensional sensing device of the present invention is small in size and can detect vibration signals in three dimensions, with better detection effect.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 A schematic diagram of the internal structure of the end cover according to an embodiment of the present invention; Figure 3 A schematic diagram of magnet distribution according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a suspended mass block according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the internal structure of a suspended mass block according to an embodiment of the present invention; Figure 6 Schematic diagram of an optical fiber end face according to an embodiment of the present invention.

[0018] Reference numerals 1. Single-mode optical fiber; 2. Upper end cover; 3. Magnet; 4. Suspended mass block; 5. Optical fiber end face; 6. Lower end cover; 7. Optical fiber bundle; 8. Fixing plate. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0020] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products or devices.

[0021] Like reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0023] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Example like Figure 1 As shown, a three-dimensional sensing device for underwater seismic wave detection described in the present invention includes an upper end cover 2 and a lower end cover 6 connected to each other, the upper end cover 2 and the lower end cover 6 are fixed by a locking element, and a fixing plate 8 is provided on the upper end cover 2 and the lower end cover 6, and a fixing hole is provided on the fixing plate 8, and the locking element is provided in the fixing hole. The locking element can be a bolt, and the fixing hole can be a hole with a thread. The fixing plate 8 is locked by the bolt to fix the upper end cover 2 and the lower end cover 6. The upper end cover 2 and the lower end cover 6 are both metal covers, and the thickness of the upper end cover 2 and the lower end cover 6 is greater than 3 mm. In order to ensure the structural safety and compressive strength, the specific radius and length can be formulated according to the engineering needs.

[0025] like Figure 2 As shown, a spherical cavity is arranged inside the sphere composed of the upper end cover 2 and the lower end cover 6, and an interacting magnet 3 and a suspended mass block 4 are arranged inside the spherical cavity. Figure 3As shown, there are five magnets 3, and the suspended mass block 4 is located at the center of the spherical cavity. The five magnets 3 are distributed at the center of the front, rear, left, right, and bottom sides of the suspended mass block 4, and the magnets 3 are arranged on the inner wall of the spherical cavity. Figure 4 As shown, the suspended mass block 4 is a hollow shell, and the suspended mass block 4 is a magnetic metal such as iron, cobalt, nickel, etc. The suspended mass block 4 is suspended in the center of the spherical cavity through the interaction between the five magnets 3 and the suspended mass block 4. The shape of the suspended mass block 4 is arbitrary, such as a sphere, a cube, etc. The size of the suspended mass block 4 is adapted to the size and strength of the magnet 3 to ensure that the appropriate distance is maintained between the magnet 3 and the suspended mass block 4 to avoid affecting the detection range of the vibration signal. In this embodiment, the suspended mass block 4 is a cube.

[0026] like Figure 5 , Figure 6 As shown, a fiber bundle 7 is arranged on the sphere composed of the upper end cover 2 and the lower end cover 6, and the bottom end of the fiber bundle 7 extends into the suspended mass block 4, and the bottom end of the fiber bundle 7 is an axially arranged fiber end face 5. An opening is arranged on the upper end cover 2, and the fiber bundle 7 is located in the opening. The fiber bundle 7 includes three single-mode optical fibers 1, and the bottom end of each single-mode optical fiber 1 corresponds to a fiber end face 5. With the center of the spherical cavity as the origin, the two mutually perpendicular axes on the axial plane formed by the centers of the magnets 3 distributed at the front, rear, left and right positions of the suspended mass block 4 as the x-axis and y-axis, and the direction perpendicular to the axial plane as the z-axis, a three-dimensional spatial coordinate is established, and the directions in which the three fiber end faces 5 are arranged are the axial directions of the three axes of the three-dimensional spatial coordinate.

[0027] The three surfaces on the inner wall of the suspended mass block 4 corresponding to the three fiber end faces 5 are test surfaces, and the three test surfaces of the suspended mass block 4 and the three fiber end faces 5 are all coated with high reflectivity films. A Fabry-Perot interferometer cavity is formed between the test surface and the corresponding fiber end faces 5.

[0028] The method for manufacturing a three-dimensional sensing device for underwater seismic wave detection described in the present invention comprises the following steps: Step 1: The three test surfaces and three optical fiber end faces 5 inside the suspended mass block 4 are coated with a high reflectivity film. The test surface is the inner surface of the suspended mass block 4 pointed to by the three optical fiber end faces 5, and the five magnets 3 are fixed at the center position of the required surface of the spherical cavity. Here, the required surface of the spherical cavity refers to the surface of the spherical cavity in the corresponding direction of the three test surfaces of the suspended mass block 4, and its center position is the position of the center position of the test surface corresponding to the surface of the spherical cavity.

[0029] Step 2: Place the suspended mass block 4 at the center of the spherical cavity and control the distance between the suspended mass block 4 and the three test surfaces, and fix the upper end cover 2, the lower end cover 6 and the optical fiber bundle 7 accordingly.

[0030] Step 3, the stripped and cut single-mode optical fiber 1 is fused with the jumper, and then connected to the demodulation system to measure the acoustic field vibration signal. The type of single-mode optical fiber 1 is not limited, and it needs to be compatible with the demodulation method. The loss of the single-mode optical fiber 1 can be ignored. The demodulation system is an existing system.

[0031] The induction method of the underwater seismic wave detection three-dimensional induction device described in the present invention comprises the following steps: When the three-dimensional sensing device is subjected to a vibration signal parallel to the axial direction of the suspended mass block 4, the suspended mass block 4 will be offset in the axial direction due to the inertia of the suspended mass block 4, causing the length of the Fabry-Perot interference cavity inside the suspended mass block 4 to increase or decrease in the radial direction, resulting in a phase change. The phase change caused by the vibration in the sound field is obtained by demodulation, thereby realizing the measurement of the underwater sound field vibration signal.

[0032] Therefore, the present invention adopts the above-mentioned three-dimensional sensing device, sensing method and manufacturing method for underwater seismic wave detection, which can dynamically monitor the vibration signals of underwater seismic waves in real time, and has a simpler structure, can measure three dimensions, and has higher sensitivity and resolution.

[0033] 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. A three-dimensional sensing device for underwater seismic wave detection, characterized in that: It includes an upper end cover and a lower end cover connected to each other. A spherical cavity is arranged inside the sphere formed by the upper end cover and the lower end cover. A plurality of interacting magnets and a suspended mass block are arranged inside the spherical cavity. An optical fiber bundle is arranged on the sphere formed by the upper end cover and the lower end cover. The bottom end of the optical fiber bundle extends into the suspended mass block. The bottom end of the optical fiber bundle is an axially arranged optical fiber end face.

2. The three-dimensional sensing device for underwater seismic wave detection according to claim 1, characterized in that: The suspended mass block is located at the center of the spherical cavity, the magnets are distributed at the center positions of the front, rear, left, right and bottom sides of the suspended mass block, and the magnets are arranged on the inner wall of the spherical cavity.

3. The three-dimensional sensing device for underwater seismic wave detection according to claim 1, characterized in that: An opening is arranged on the upper end cover, and the optical fiber bundle is located in the opening.

4. The three-dimensional sensing device for underwater seismic wave detection according to claim 1, characterized in that: The optical fiber bundle includes three single-mode optical fibers, and the bottom end of each single-mode optical fiber corresponds to a fiber end face.

5. The three-dimensional sensing device for underwater seismic wave detection according to claim 4, characterized in that: Taking the center of the spherical cavity as the origin, the two mutually perpendicular axes on the axial plane formed by the centers of the magnets distributed at the front, rear, left and right positions of the suspended mass block as the x-axis and y-axis, and the direction perpendicular to the axial plane as the z-axis, a three-dimensional spatial coordinate is established, and the directions in which the three optical fiber end faces are set are the axial directions of the three axes of the three-dimensional spatial coordinate.

6. The three-dimensional sensing device for underwater seismic wave detection according to claim 4, characterized in that: The three surfaces on the inner wall of the suspended mass block corresponding to the three optical fiber end faces are test surfaces. The three test surfaces of the suspended mass block and the three optical fiber end faces are all coated with high reflectivity films, and a Fabry-Perot interference cavity is formed between the test surfaces and the corresponding optical fiber end faces.

7. The three-dimensional sensing device for underwater seismic wave detection according to claim 1, characterized in that: The suspended mass block is a hollow shell and is made of magnetic material.

8. The three-dimensional sensing device for underwater seismic wave detection according to claim 1, characterized in that: The upper end cover and the lower end cover are fixed by a locking element. Both the upper end cover and the lower end cover are provided with a fixing plate, the fixing plate is provided with a fixing hole, and the locking element is arranged in the fixing hole.

9. The method for manufacturing the three-dimensional sensing device for underwater seismic wave detection according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: coat the three test surfaces and three optical fiber end faces inside the suspended mass block with a high reflectivity film, and fix all five magnets at the center of the required surface of the internal sphere; Step 2: Place the suspended mass block at the center of the spherical cavity, and control the distance between the three test surfaces inside the suspended mass block and the end face of the optical fiber, and fix the upper end cover, the lower end cover and the optical fiber bundle accordingly; Step three, the stripped and cut single-mode optical fiber is fused with the jumper, and then connected to the demodulation system to measure the acoustic field vibration signal.

10. The sensing method of the three-dimensional sensing device for underwater seismic wave detection according to any one of claims 1 to 8, characterized in that: The following steps are involved: When the three-dimensional sensing device is subjected to a vibration signal parallel to the axial direction of the suspended mass block, the suspended mass block will be offset in the axial direction due to the inertia of the suspended mass block, causing the length of the Fabry-Perot interference cavity inside the suspended mass block to increase or decrease in the radial direction, resulting in a phase change. The phase change caused by the vibration in the sound field is obtained by demodulation, thereby realizing the measurement of the underwater sound field vibration signal.

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