Optical fiber hydrophone with self-balancing system active adjustment

Abstract

This invention discloses a fiber optic hydrophone with a self-balancing system for active adjustment, comprising a hydraulic assembly, a pneumatic assembly, and a detector. The hydraulic assembly includes a back pressure oil bladder and a piston oil bladder. The back pressure oil bladder senses the water depth pressure and transmits it to the oil chamber of the detector. The piston oil bladder actively adjusts the pressure by changing its volume and transmits the pressure to the oil chamber of the detector. The pneumatic assembly actively adjusts the pressure within the gas cavity of the detector by adjusting the volume of the gas bladder. The detector includes a reference arm base and a measuring arm base. The measuring arm base is disposed outside the reference arm base. A sealing layer is provided outside the measuring arm base. The inner side of the measuring arm base is a gas cavity. The area between the outer side of the measuring arm base and the sealing layer is the oil cavity. This invention achieves self-balancing and active adjustment of underwater pressure in the fiber optic hydrophone through the hydraulic and pneumatic assemblies, and improves detection sensitivity.

Description

Technical Field

[0001] This invention relates to a fiber optic hydrophone, and more particularly to a fiber optic hydrophone with an active adjustment system for self-balancing. Technical Background

[0002] A fiber optic hydrophone is an underwater acoustic detection system. When subjected to sound pressure, the optical signal in the sensor's detection arm is modulated, while the optical signal in the sensor's reference arm is not modulated. The two coherent beams interfere with each other in the coupler after being reflected by a Faraday rotator. The interference signal is converted into an electrical signal by a photodetector, and the amplitude and frequency of the corresponding acoustic signal are detected by a demodulation algorithm.

[0003] Existing fiber optic hydrophones have the following problems: 1. They cannot effectively achieve oil pressure self-balancing in deep-sea exploration. 2. They cannot actively adjust the pressure to control changes in the fiber optic length of the probe arm, resulting in weak detection capabilities. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a fiber optic hydrophone with an active adjustment system for self-balancing.

[0005] The objective of this invention is achieved through the following technical solution: An embodiment of this invention provides a fiber optic hydrophone with an active self-balancing system, comprising:

[0006] The hydraulic assembly includes a back pressure oil bladder and a piston oil bladder. The back pressure oil bladder is used to sense the water depth pressure and transmit the water depth pressure to the oil chamber of the detector. The piston oil bladder actively adjusts the pressure by changing the volume of the oil bladder and transmits the pressure to the oil chamber of the detector.

[0007] A pneumatic assembly, comprising an airbag, wherein the pressure inside a gas cavity in the detector is actively regulated by adjusting the volume of the airbag.

[0008] The detector includes a reference arm base and a measuring arm base; the measuring arm base is disposed outside the reference arm base; a sealing layer is disposed outside the measuring arm base; the inner side of the measuring arm base is a gas cavity; and the area between the outer side of the measuring arm base and the sealing layer is an oil cavity.

[0009] Furthermore, a perforated oil bladder cylinder is provided on the outer side of the back pressure oil bladder, and a filter sponge is provided inside the perforated oil bladder cylinder near the left side of the back pressure oil bladder. The right end of the back pressure oil bladder is fixed to the end cap by a first oil bladder clamp, and a first oil nozzle is provided on the end cap.

[0010] Furthermore, the piston oil bladder is encased in a wear-resistant sheath; a piston pusher is installed on the left side of the piston oil bladder, and the piston pusher performs linear reciprocating motion to change the volume of the piston oil bladder, thereby changing the output pressure of the piston oil bladder and thus actively changing the pressure of the detector's oil chamber; the right side of the piston oil bladder is connected to the inner end face of the sealed chamber through a second oil bladder clamp, and a third oil nozzle is installed on the outer end face of the sealed chamber, which is connected to the detector through an oil passage pipe.

[0011] Furthermore, the wear-resistant sheath is made of polytetrafluoroethylene.

[0012] Furthermore, the piston pusher is driven by a linear motor to perform linear reciprocating motion, thereby changing the volume of the piston oil bladder. The power and control lines of the linear motor are led out through a watertight connector.

[0013] Furthermore, the inner surface of the sealed chamber is coated with a smooth and wear-resistant layer, and the material of the smooth and wear-resistant layer can be polytetrafluoroethylene.

[0014] Furthermore, the pneumatic assembly includes an airbag cylinder and an airbag disposed within the airbag cylinder. A first displacement sensor and a second displacement sensor are respectively disposed at the initial position and the end of the airbag. A first air nozzle and a second air nozzle are respectively disposed on the right side of the airbag cylinder. The first air nozzle enables communication between the pneumatic assembly and the gas cavity in the detector. The second air nozzle is connected to the gas cylinder via a second one-way solenoid valve, and a first one-way solenoid valve is disposed on a branch of the pipeline connecting the second air nozzle and the second one-way solenoid valve.

[0015] Furthermore, the detector is a spindle-type interferometric fiber optic hydrophone.

[0016] Furthermore, the detector includes a coaxial reference arm base and a measurement arm base; the measurement arm base is disposed outside the reference arm base, and a measurement arm elastomer is wound on the measurement arm base; the reference arm optical fiber is wound on the reference arm base; two O-rings are radially disposed on the reference arm base for sealing to isolate seawater; a sealing layer is disposed outside the measurement arm base to isolate seawater and protect the internal optical fiber.

[0017] Furthermore, the material of the measuring arm elastomer is selected from polyurethane or nylon.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. The device of this invention achieves underwater pressure self-balancing of the detector through a back pressure oil bladder in the field of deep-sea exploration; 2. The piston oil bladder provides pressure to actively adjust the length of the optical fiber wound on the probe arm, thereby improving the detection performance of the optical fiber hydrophone; 3. By changing the pressure inside the gas cavity through pneumatic components, different gas cavity pressures are used for different sea depths, thereby improving the detection performance of the optical fiber hydrophone. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the device of the present invention;

[0022] Figure 2 This is a schematic diagram of a hydraulic assembly;

[0023] Figure 3 This is a cross-sectional schematic diagram of the detector;

[0024] Figure 4 This is a schematic diagram of a pneumatic component;

[0025] In the diagram, 200-hydraulic assembly, 211-filter sponge; 212-perforated oil bladder cylinder, 213-back pressure oil bladder, 214-first oil bladder clamp, 215-first oil nozzle, 221-second oil nozzle, 222-watertight connector, 223-linear motor, 224-piston pusher, 225-piston oil bladder, 226-wear-resistant sleeve, 227-sealed chamber, 228-second oil bladder clamp, 229-third oil nozzle; 300-pneumatic assembly, 311-first displacement sensor, 3 12-Airbag body, 313-Airbag, 314-Second displacement sensor, 315-First air nozzle, 316-Second air nozzle, 317-First one-way solenoid valve, 318-Second one-way solenoid valve, 319-Gas cylinder; 400-Detector, 411-Fourth oil nozzle, 412-Third air nozzle, 413-Measuring arm base, 414-Measuring arm elastomer, 415-Reference arm base, 416-Gas cavity, 417-Oil cavity, 418-Sealing layer, 419-Side mounting cover. Detailed Implementation

[0026] To make the objectives and technical solutions of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0027] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Generally, the components of the embodiments of the invention described and shown in the accompanying drawings can be implemented with other different details, structural variations, and dimensional changes. The accompanying drawings of specific embodiments of the present invention are intended to more clearly describe an optical fiber hydrophone with a self-balancing system for active adjustment, and are not intended to limit the size, dimensions, or shape of the internal components.

[0028] like Figure 1 As shown in the figure, this invention proposes an active-adjustment fiber optic hydrophone with a self-balancing system, comprising a hydraulic assembly 200, a pneumatic assembly 300, and a detector 400. The output of the hydraulic assembly is connected to the input of the detector, and the output of the pneumatic assembly is also connected to the input of the detector. The hydraulic assembly includes a motor assembly, a piston assembly, and a back pressure oil bladder assembly. The motor assembly and piston assembly provide active hydraulic pressure, while the back pressure oil bladder assembly provides passive pressure from seawater. The pneumatic assembly provides active gas pressure to the system. This invention achieves self-balancing and active pressure adjustment of underwater pressure through the hydraulic and pneumatic assemblies, providing a fiber optic hydrophone for use in the deep sea field with high detection sensitivity.

[0029] like Figure 2 As shown, the hydraulic assembly 200 consists of a back pressure oil bladder 213 and a piston oil bladder 225. The outer layer of the back pressure oil bladder 213 contacts seawater, and the bladder is filled with silicone oil. An outer shell (i.e., a perforated oil bladder cylinder 212) protects the oil bladder from rupture and other risks, transmitting seawater pressure to the outside of the piston oil bladder 225 via the back pressure oil bladder 213. Specifically, a filter sponge 211 is installed inside the perforated oil bladder cylinder 212, near the left side of the back pressure oil bladder 213, to prevent sediment from entering. The right end of the back pressure oil bladder 213 is fixed to an end cap by a first oil bladder clamp 214. The end cap has a first oil nozzle 215, which is connected to a second oil nozzle 221 via an oil passage pipe, thus transmitting seawater pressure to the outside of the piston oil bladder 225. The piston oil bladder 225 is encased in a wear-resistant sleeve 226, which is a cylinder made of polytetrafluoroethylene (PTFE). A piston pusher 224 is mounted on the left side of the piston oil bladder 225. The piston pusher 224 is driven by a linear motor 223 to change the volume of the piston oil bladder 225, thereby altering its output pressure and actively changing the pressure within the detector oil chamber 417. The power and control lines of the linear motor 223 are led out through a watertight connector 222. The piston oil bladder 225 and its accessories are housed within a sealed chamber 227. The inner surface of the sealed chamber 227 is coated with a smooth, wear-resistant layer, which can be made of PTFE. The right side of the piston oil bladder 225 is connected to the inner end face of the sealed chamber 227 via a second oil bladder clamp 228. A third oil nozzle 229 is mounted on the outer end face of the sealed chamber 227 and connected to the detector 400 via an oil passage.

[0030] The outer side of the piston oil bladder 225 in the hydraulic assembly 200 is connected to the inner side of the back pressure oil bladder 213, and the inner side of the piston oil bladder 225 is connected to the oil chamber of the detector 400. The piston oil bladder 225 is integrally installed inside the metal sealed housing 227. The back pressure oil bladder 213 is located in the perforated oil bladder cylinder 212, which is a water-permeable thin-walled shell. Seawater pressure is directly transmitted to the back pressure oil bladder 213, and then the pressure is transmitted through the piston oil bladder 225 to the oil chamber of the detector, so that the internal and external pressures of the thin-walled shell of the detector are balanced.

[0031] like Figure 4 As shown, the pneumatic assembly 300 includes a first displacement sensor 311, an airbag body 312, an airbag 313, a second displacement sensor 314, a first air nozzle 315, a second air nozzle 316, a first one-way solenoid valve 317, a second one-way solenoid valve 318, and a gas cylinder 319. The airbag body 312 houses the airbag 313. The first displacement sensor 311 and the second displacement sensor 314 are respectively located on the left and right sides of the airbag 313 (i.e., the initial position and the end of the airbag 313). These sensors sense the position of the airbag 313 and its inflation and deflation actions. The first air nozzle 315 and the second air nozzle 316 are located on the right side of the airbag body 312. The first air nozzle 315 is connected to the detector 400 via a pipe. The second air nozzle 316 is connected to the gas cylinder 319 via the second one-way solenoid valve 318 and a pressure reducing valve (not shown in the figure). A first one-way solenoid valve 317 is installed on a branch of the pipeline connecting the second air nozzle 316 and the second one-way solenoid valve 318. The airbag 313 is deflated through the first one-way solenoid valve 317. The inflation and deflation of the gas cylinder 319 are controlled by the first one-way solenoid valve 317 and the second one-way solenoid valve 318 to change the pressure of the airbag 313. The outer side of the airbag cylinder 312 is seawater, and the inner side is gas. The space inside the airbag 313 is interconnected with the gas cavity in the detector 400.

[0032] The inflation and deflation process is as follows: Displacement sensors are installed at both the initial and final positions of the airbag 313. When the displacement sensors detect a signal, the airbag 313 inflates or deflates. In this embodiment, when the airbag 313 shrinks to its initial position, inflation begins, with the high-pressure gas from the gas cylinder 319 being depressurized by a pressure reducing valve and then injected into the airbag 313 through the second one-way solenoid valve 318. When the airbag 313 expands to its final position, deflation begins, releasing the gas from the airbag 313 into the seawater. The air source for the airbag 313 is the high-pressure gas cylinder 319; the gas released from the high-pressure gas cylinder 319 enters the airbag through the pressure reducing valve and the second one-way solenoid valve 318.

[0033] like Figure 3As shown, the detector 400 includes a fourth oil nozzle 411, a third gas nozzle 412, a measuring arm base 413, a measuring arm elastomer 414, a reference arm base 415, a gas cavity 416, an oil cavity 417, a sealing layer 418, and a lateral mounting cover 419. The detector 400 provided in this embodiment is a spindle-type interferometric fiber optic hydrophone, and its shape is cylindrical. A cross-sectional view of the detector 400 is shown below. Figure 3 As shown. A fourth oil nozzle 411 and a third air nozzle 412 are provided on the left end face of the detector 400. The fourth oil nozzle 411 is connected to the hydraulic assembly, enabling communication between the hydraulic assembly 200 and the oil cavity 417. The third air nozzle 412 is connected to the pneumatic assembly 300, enabling communication between the pneumatic assembly 300 and the gas cavity 416. The detector 400 includes a coaxial reference arm base 415 and a measuring arm base 413. The measuring arm base 413 is disposed outside the reference arm base 415, and a measuring arm elastomer 414 is wound on the measuring arm base 413. The measuring arm elastomer 414 is made of polyurethane or nylon. The reference arm optical fiber is wound on the reference arm base 415. The reference arm base 415 is a metal component (such as aerospace aluminum), which has good shape retention, ensuring that the optical fiber length of the reference arm is consistent with the initial reference. Two O-rings are radially arranged on the reference arm base 415 for sealing to isolate seawater. The measuring arm base 413 is provided with a sealing layer 418 to isolate seawater and protect the internal optical fiber.

[0034] The outer side of the measuring arm base 413 is an oil cavity 417, and the inner side is a gas cavity 416. Specifically, the area between the outer side of the measuring arm base 413 and the outermost sealing layer 418 is the detector's oil cavity 417, and the area between the inner side of the measuring arm base 413 and the reference arm base 415 is the detector's gas cavity 416. Since the elastic body wound around the measuring arm base 413 is relatively flexible, changing the oil cavity and pressure can change the size of the elastic body, thereby changing the length of the probe arm fiber. For interferometric fiber optic hydrophones, ensuring that the probe arm fiber and the reference arm fiber are of equal length is essential to guarantee the detector's detection performance. The detector's measuring arm is used to sense changes in seawater pressure; therefore, an internal gas cavity is designed. By changing the pressure in the gas cavity, it adapts to different sea depths, further improving the detector's adaptability to different sea depths. The introduction of the gas cavity also helps improve the detector's detection performance.

[0035] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only.

[0036] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A fiber optic hydrophone with a self-balancing system for active adjustment, characterized in that, include: The hydraulic assembly (200) includes a back pressure oil bladder (213) and a piston oil bladder (225). The back pressure oil bladder (213) is used to sense the water depth pressure and transmit the water depth pressure to the oil chamber of the detector (400). The piston oil bladder (225) actively adjusts the pressure by changing the oil bladder volume and transmits the pressure to the oil chamber of the detector (400). The right end of the back pressure oil bladder (213) is fixed to the end cap by a first oil bladder clamp (214). The end cap is provided with a first oil nozzle (215). The first oil nozzle (215) is connected to a second oil nozzle (221) through an oil passage to transmit the seawater pressure to the outside of the piston oil bladder (225). A pneumatic assembly (300) includes an airbag (313) whose volume is adjusted to actively regulate the pressure inside a gas cavity (416) in a detector (400); the pneumatic assembly (300) includes an airbag cylinder (312) and an airbag (313) disposed within the airbag cylinder (312); a first displacement sensor (311) and a second displacement sensor (314) are respectively disposed at the initial position and the end of the airbag (313); the airbag cylinder (312) of the airbag cylinder (312)... A first air nozzle (315) and a second air nozzle (316) are respectively provided on the right side; the pneumatic assembly (300) and the gas cavity (416) in the detector (400) are interconnected through the first air nozzle (315); the second air nozzle (316) is connected to the gas cylinder (319) through the second one-way solenoid valve (318), and a first one-way solenoid valve (317) is provided on the branch of the pipeline connecting the second air nozzle (316) and the second one-way solenoid valve (318); the outer side of the airbag cylinder (312) is seawater, and the inner side is gas; The detector (400) includes a reference arm base (415) and a measuring arm base (413); the measuring arm base (413) is disposed outside the reference arm base (415); a sealing layer (418) is disposed outside the measuring arm base (413); the inner side of the measuring arm base (413) is a gas cavity (416); the area between the outer side of the measuring arm base (413) and the sealing layer (418) is an oil cavity (417).

2. The fiber optic hydrophone with self-balancing system active adjustment according to claim 1, characterized in that, The back pressure oil bladder (213) is provided with a perforated oil bladder cylinder (212) on the outside. A filter sponge (211) is provided inside the perforated oil bladder cylinder (212) on the left side of the back pressure oil bladder (213). The right end of the back pressure oil bladder (213) is fixed to the end cap by a first oil bladder clamp (214). The end cap is provided with a first oil nozzle (215).

3. The fiber optic hydrophone with self-balancing system active adjustment according to claim 1, characterized in that, The piston oil bladder (225) is wrapped by a wear-resistant sleeve (226); a piston pusher (224) is installed on the left side of the piston oil bladder (225), and the piston pusher (224) makes a linear reciprocating motion to change the volume of the piston oil bladder (225) to change the output pressure of the piston oil bladder (225), thereby actively changing the pressure of the oil chamber (417) of the detector; the right side of the piston oil bladder (225) is connected to the inner end face of the sealed chamber (227) through a second oil bladder clamp (228), and a third oil nozzle 229 is installed on the outer end face of the sealed chamber (227), which is connected to the detector (400) through an oil pipeline.

4. The fiber optic hydrophone with self-balancing system active adjustment according to claim 3, characterized in that, The wear-resistant sheath (226) is made of polytetrafluoroethylene.

5. The fiber optic hydrophone with self-balancing system active adjustment according to claim 3, characterized in that, The piston pusher (224) is driven by a linear motor (223) to perform linear reciprocating motion so that the volume of the piston oil bladder (225) changes. The power line and control line of the linear motor (223) are led out through a watertight connector (222).

6. The fiber optic hydrophone with self-balancing system active adjustment according to claim 3, characterized in that, The inner surface of the sealed chamber (227) is also coated with a smooth and wear-resistant layer, the material of which is polytetrafluoroethylene.

7. The fiber optic hydrophone with self-balancing system active adjustment according to claim 1, characterized in that, The detector (400) is a spindle-type interferometric fiber optic hydrophone.

8. The fiber optic hydrophone with self-balancing system active adjustment according to claim 7, characterized in that, The detector (400) includes a coaxial reference arm base (415) and a measuring arm base (413); the measuring arm base (413) is disposed outside the reference arm base (415), and a measuring arm elastomer (414) is wound on the measuring arm base (413); the reference arm optical fiber is wound on the reference arm base (415); two O-rings are radially disposed on the reference arm base (415) for sealing to isolate seawater; a sealing layer (418) is disposed outside the measuring arm base (413) to isolate seawater and protect the internal optical fiber.

9. The fiber optic hydrophone with self-balancing system active adjustment according to claim 8, characterized in that, The material of the measuring arm elastomer (414) is polyurethane or nylon.

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