Superfine-diameter optical fiber towed line array vibration reduction and isolation module

Abstract

The utility model discloses a superfine-diameter optical fiber towed line array vibration reduction and isolation module, which relates to the field of underwater acoustic sensing and comprises two array connectors, and a sheath is mounted between the two array connectors. The two force bearing pieces are fixedly installed on the corresponding array connectors, the other ends of the force bearing pieces extend into the sheath, and force bearing rope holes and elastic rope holes are formed in the force bearing pieces; the bearing skeletons are arranged at equal intervals along the axial direction of the sheath; one end of the elastic rope is fixed to one force bearing piece through the elastic rope hole, and the other end of the elastic rope sequentially penetrates through the force bearing frameworks and then is fixed to the elastic rope hole of the other force bearing piece; the force-bearing rope is divided into two strands, penetrates out of the force-bearing rope hole of one force-bearing piece, is arranged along the outer wall of each force-bearing framework, penetrates into the force-bearing rope hole of the other force-bearing piece and is combined into one strand; and the flexible optical cables are arranged along the outer walls of the bearing frameworks. According to the utility model, the zero-buoyancy balancing of the whole array is realized, the development of the array with the diameter phi of 16mm and the low-speed towing test on the lake are completed, and the device has important application value in the field of underwater acoustic sensing.

Description

Technical Field

[0001] This utility model relates to the field of underwater acoustic sensing, specifically to an ultra-fine diameter fiber optic towed array vibration reduction and isolation module. Background Technology

[0002] With the emergence of the concept of "distributed warfare," major naval powers worldwide are developing unmanned surface and underwater platforms as crucial equipment for implementing this strategy. Compared to manned platforms with their large displacement and payload capacity, unmanned platforms have very limited space and payload capacity, severely restricting the scale and detection capabilities of traditional towed linear array systems. Therefore, there is an urgent need to develop smaller hydrophones and finer-diameter arrays. Reports indicate that countries such as Singapore and the UK have been developing ultra-fine-diameter hydrophones and linear arrays. A recent example is the 20m long, 20mm outer diameter digital fine linear array developed in 2017 by the British companies AutoNaut and Seiche. The array elements exhibit high acoustic sensitivity over a wide bandwidth (10Hz-2kHz), with an array spacing of 0.25m. Joint experimental research was conducted on a USV-towed fine linear array, primarily for the detection and defense of submarines and other underwater targets. A 2018 Jane's Defence Weekly report described how the UK-based Systems Engineering & Assessment Ltd (SEA) developed the Krait Array, an ultra-fine towed linear array specifically for small anti-submarine platforms such as small ships, unmanned surface vessels, and underwater unmanned vehicles. It integrates 128 low-power, miniature, high-sensitivity, broadband hydrophones and 32 miniature non-acoustic sensors, achieving an outer diameter of 16mm and a working depth of 300m. This ultra-fine array has entered the final testing phase. However, the report also noted that most foreign ultra-fine hydrophones and arrays employ digital electrical hydrophone solutions, primarily targeting applications on small platforms. There is a lack of reports on ultra-fine linear array technology based on fiber optic hydrophones from abroad.

[0003] Existing towed linear array vibration isolation modules are limited by zero buoyancy requirements, making it difficult to achieve miniaturized engineering applications with ultra-small diameters. To meet the application requirements of ultra-small diameter fiber optic towed linear array sonar, it is necessary to simultaneously conduct research on ultra-small diameter fiber optic towed linear array vibration reduction and isolation modules, and solve problems such as skeleton design, elastic rope deployment, optical cable deployment, zero buoyancy balancing, and solid adhesive filling in the miniaturization design of vibration reduction and isolation modules. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an ultra-fine diameter fiber optic towed array vibration reduction and isolation module. It overcomes the manufacturing challenges of a 30m long, Φ16mm diameter fiber optic towed array, integrating multiple functional components such as array connectors, elastic ropes, load-bearing ropes, load-bearing frames, flexible optical cables, and load-bearing parts into a limited internal space. This achieves the ability to suppress vortex-induced vibration of the ultra-fine diameter fiber optic towed array at low tow speeds. This vibration reduction and isolation module can be applied to military and civilian fiber optic towed array sonar systems. Its ultra-miniaturized design can effectively alleviate the load pressure on ships and has good application prospects in the field of underwater acoustic sensing.

[0005] The objective of this invention is achieved through the following technical solution: This ultra-fine diameter fiber optic towed array vibration reduction and isolation module includes:

[0006] Two array connectors are respectively located at both ends of the vibration isolation module, and a protective sleeve is installed between the two array connectors;

[0007] Two load-bearing components are fixedly installed on the corresponding array connectors. The other end of the load-bearing component extends into the sheath and has load-bearing rope holes and elastic rope holes.

[0008] Several load-bearing frames are arranged at equal intervals along the axial direction of the inner cavity of the sheath to support the sheath.

[0009] The elastic rope is threaded inside the sheath. One end of the rope is fixed to a load-bearing component through the elastic rope hole, and the other end passes through each load-bearing frame in sequence before being fixed to the elastic rope hole of another load-bearing component.

[0010] The load-bearing rope, threaded inside the sheath, is divided into two strands that emerge from the load-bearing rope hole of one load-bearing component, run along the outer wall of each load-bearing frame, and then enter the load-bearing rope hole of another load-bearing component, where they merge into one strand; and

[0011] The flexible optical cable is run inside the sheath and along the outer wall of each load-bearing frame, with both ends of the flexible optical cable connected to the corresponding array connectors.

[0012] As a further technical solution, a cylindrical platform is provided at one end of the load-bearing component and the array connector. The cylindrical platform is embedded in the array connector and is pressed by a pressure ring to achieve fixation.

[0013] As a further technical solution, each load-bearing frame has a hole for passing through an elastic rope at its center. The outer walls of the load-bearing frame are symmetrically provided with load-bearing rope placement slots on both sides for laying and routing the load-bearing ropes. Several flexible optical cable installation slots are evenly distributed on the outer walls of the load-bearing frame between the two load-bearing rope placement slots for laying and routing the flexible optical cables. The load-bearing frame is made of glass microsphere material.

[0014] As a further technical solution, the sheath is made of PU material and formed into a tubular structure with an outer diameter not exceeding Φ15mm.

[0015] As a further technical solution, the load-bearing rope is a flat, wear-resistant rope with a breaking tensile strength of not less than 150 kg.

[0016] As a further technical solution, the flexible optical cable uses a Teflon-coated metal flexible armor tube and lays a pair of small-diameter micro-bending filaments inside the flexible optical cable.

[0017] As a further technical solution, the inner cavity of the sheath is filled with low-density solid adhesive, with a density not exceeding 0.90 g / cm³ after curing. 3 .

[0018] As a further technical solution, the array connector and load-bearing components are made of TC4 titanium alloy material, which has a tensile strength of not less than 895MPa and a specified residual elongation stress of not less than 830MPa.

[0019] As a further technical solution, the elastic rope is made of ultra-fine single-braided nylon rope with a diameter of Φ2mm, and the elongation at low drag speed does not exceed 15%.

[0020] The beneficial effects of this utility model are as follows:

[0021] 1. Using flexible optical cables, low-density polyurethane adhesive, low-density skeleton and other materials, the diameter of the towed linear array vibration reduction and isolation module does not exceed 16mm, realizing the ultra-miniaturization design of fiber optic towed linear array sonar and meeting the load capacity limitation requirements of underwater acoustic sensing unmanned platform.

[0022] 2. The load-bearing components are provided with holes for the load-bearing rope and the elastic rope. The two types of rope are evenly distributed between the load-bearing components after passing through the holes, and they do not interfere with each other.

[0023] 3. The load-bearing frame is arranged at equal intervals in the array to support the sheath. It is made of glass microsphere material, which is highly malleable, lightweight, and pressure resistant, meeting the needs of shallow sea working depth application scenarios.

[0024] 4. The elastic rope is preferably made of ultra-fine single-braided nylon rope with a diameter of Φ2mm. The elongation at low drag speed does not exceed 15%. The thin rope is threaded and laid out through the elastic rope hole on the load-bearing component and the elastic rope threading hole on the load-bearing frame.

[0025] 5. The load-bearing rope is preferably a flat, wear-resistant rope with a breaking tensile strength of not less than 150kg, which meets the tensile requirements of ultra-fine diameter fiber optic tow arrays at low towing speeds.

[0026] 6. A tubular outer sheath with an outer diameter not exceeding Φ15mm is used as an elastic load-bearing auxiliary structure for the linear array, which effectively reduces vortex-induced jitter of the fiber optic drag array at low drag speed.

[0027] 7. The remaining space inside the sheath is filled with low-density solid adhesive, which has strong fluidity before curing and can fill the array at high speed. After curing, the density is no more than 0.90 g / cm³. 3 The array as a whole achieves a zero buoyancy design, and after being assembled, it meets the zero buoyancy requirements of seawater, with a diameter range of 15.50mm to 15.99mm. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of this utility model.

[0029] Figure 2 This is a structural schematic diagram of the load-bearing component in this utility model.

[0030] Figure 3 This is a schematic diagram of the load-bearing frame in this utility model.

[0031] Figure 4 This is a schematic diagram of the tension-elongation relationship of the elastic rope in this utility model.

[0032] Explanation of reference numerals in the attached drawings: Array connector 1, load-bearing component 2, load-bearing rope 3, load-bearing frame 4, sheath 5, flexible optical cable 6, elastic rope 7, pressure ring 8, load-bearing rope hole 9, elastic rope hole 10, load-bearing rope laying groove 11, elastic rope threading hole 12, flexible optical cable installation groove 13, cylindrical platform 14. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings:

[0034] Example: As attached Figures 1-4 As shown, this ultra-fine diameter fiber optic towed array vibration reduction and isolation module includes an array connector 1, a load-bearing component 2, a load-bearing rope 3, a load-bearing frame 4, a sheath 5, a flexible optical cable 6, an elastic rope 7, a pressure ring 8, a load-bearing rope hole 9, an elastic rope hole 10, a load-bearing rope placement groove 11, an elastic rope threading hole 12, a flexible optical cable installation groove 13, and a cylindrical platform 14.

[0035] Reference Appendix Figure 1 Two array connectors 1 are respectively located at both ends of the vibration isolation module, and a sheath 5 is installed between the two array connectors 1. Preferably, the sheath 5 is made of PU material and is made into a tubular structure with an outer diameter not exceeding Φ15mm. It serves as an elastic load-bearing auxiliary structure for the linear array, effectively reducing vortex-induced vibration of the fiber optic towed array at low tow speeds. Several load-bearing frames 4 are arranged at equal intervals along the axial direction of the inner cavity of the sheath 5 to support the sheath 5. The load-bearing frames 4 are made of glass microsphere material, which has high plasticity, light weight, and high pressure resistance, meeting the requirements of shallow sea working depth applications.

[0036] A load-bearing component 2 is installed on each array connector 1, such as... Figure 1 , 2 As shown, one end of the load-bearing component 2, which is fixed to the array connector 1, is provided with a cylindrical platform 14. The cylindrical platform 14 is embedded in the array connector 1, pressed by a pressure ring 8, and fixed by screws to prevent rotation, thereby achieving tensile strength and fixation. Furthermore, the other end of the load-bearing component 2 extends into the sheath 5, and the load-bearing component 2 has load-bearing rope holes 9 and elastic rope holes 10. Preferably, the array connector 1 and the load-bearing component 2 are made of TC4 titanium alloy material, having a tensile strength of not less than 895 MPa and a specified residual elongation stress of not less than 830 MPa.

[0037] Reference Appendix Figure 1 , 3 The elastic rope 7 is threaded inside the sheath 5, and each load-bearing frame 4 has an elastic rope hole 12 in the center for the elastic rope 7 to pass through. One end of the elastic rope 7 is fixed to one of the load-bearing components 2 through the elastic rope hole 10, and the other end of the elastic rope 7 passes through each load-bearing frame 4 in sequence and is then fixed to the elastic rope hole 10 of another load-bearing component 2.

[0038] The load-bearing rope 3 is threaded inside the sheath 5. The load-bearing rope 3 is divided into two strands, which emerge from the load-bearing rope hole 9 of one of the load-bearing components 2, run along the outer wall of each load-bearing frame 4, and then thread into the load-bearing rope hole 9 of the other load-bearing component 2, merging into one strand. Correspondingly, load-bearing rope placement grooves 11 are symmetrically opened on both sides of the outer wall of the load-bearing frame 4 for the placement and routing of the load-bearing rope 3. Simultaneously, several flexible optical cable installation grooves 13 are evenly distributed on the outer wall of the load-bearing frame 4 between the two load-bearing rope placement grooves 11 for the placement and routing of the flexible optical cable 6. The flexible optical cable 6 is threaded inside the sheath 5 and runs along the outer wall of each load-bearing frame 4, with both ends of the flexible optical cable 6 connected to the corresponding array connector 1. Preferably, the flexible optical cable 6 is made of a Teflon-coated flexible metal tube, and a pair of thin-diameter micro-bending resistant optical fibers are laid inside the flexible optical cable 6. Since the two ends of the flexible optical cable 6 are connected to the array start and end connectors respectively, the length redundancy design can be fully utilized under the condition of limited space to meet the requirements of low insertion loss transmission of optical signals.

[0039] Preferably, the load-bearing rope 3 is a flat, wear-resistant rope with a breaking tensile strength of not less than 150 kg, meeting the tensile requirements of the ultra-fine diameter fiber optic tow array at low towing speeds. The elastic rope 7 is an ultra-fine single-braided nylon rope with a diameter of Φ2 mm, and its elongation at low towing speeds does not exceed 15%. The relationship between its tension and elongation is shown in [reference needed]. Figure 4 Because the elastic rope is thin, traditional methods cannot achieve a Φ2mm rope threading. Therefore, the structure in this utility model can be used to lay out the thin rope.

[0040] Furthermore, the remaining space inside the sheath 5 is filled with a low-density solid adhesive, which has strong fluidity before curing, enabling high-speed filling of the array, and a density not exceeding 0.90 g / cm³ after curing. 3The array as a whole achieves a zero-buoyancy design.

[0041] Through the above scheme, the vibration reduction and isolation modules are finally arrayed, with a density that meets the zero buoyancy requirements of seawater and a diameter range of 15.50mm to 15.99mm.

[0042] Assembly process of this utility model:

[0043] During assembly, the cylindrical platform 14 of the load-bearing component 2 is embedded into the corresponding array connector 1, pressed tightly by the pressure ring 8, and fixed with screws to prevent rotation, thereby achieving tensile strength and fixation. A sheath 5 is installed between the two load-bearing components 2, and several load-bearing skeletons 4 are arranged at equal intervals along the axial direction of the inner cavity of the sheath 5 to support the sheath 5. One end of the elastic rope 7 is fixed to one of the load-bearing components 2 through the elastic rope hole 10, and the other end of the elastic rope 7 passes through each load-bearing skeleton 4 (elastic rope hole 10) in sequence and is then fixed to the elastic rope hole 10 of the other load-bearing component 2. The load-bearing rope 3 is divided into two strands and passes out from the load-bearing rope hole 9 of one of the load-bearing components 2. After being routed along the outer wall (load-bearing rope routing groove 11) of each load-bearing skeleton 4, it is passed into the load-bearing rope hole 9 of the other load-bearing component 2 and merged into one strand. The flexible optical cable 6 is routed along the outer wall (flexible optical cable mounting groove 13) of each load-bearing skeleton 4, and both ends of the flexible optical cable 6 are connected to the corresponding array connector 1. After the wiring and placement are completed, the remaining space inside the sheath 5 is filled with low-density solid glue to finally achieve the array of vibration reduction and isolation modules. Its density meets the zero buoyancy requirements of seawater, and its diameter ranges from 15.50mm to 15.99mm (i.e., less than 16mm).

[0044] This utility model patent provides an ultra-fine diameter fiber optic towed array vibration reduction and isolation module with a diameter not exceeding 16mm by using materials such as flexible optical cable, low-density polyurethane adhesive, and low-density skeleton, and designing an ultra-fine elastic rope threading structure, an ultra-fine cable core sheathing structure, and an adhesive filling structure. This enables the ultra-miniaturization design of fiber optic towed array sonar and meets the load capacity limitations of underwater acoustic sensing unmanned platforms.

[0045] Through miniaturized structural design, and by employing high-strength array connectors, load-bearing components, elastic ropes, load-bearing ropes, low-density skeletons, flexible optical cables, low-density solid adhesives, and sheaths, we proposed a hot-cut threading structure for elastic ropes, a sheathing structure for ultra-fine linear arrays, and a filling adhesive structure for ultra-fine linear arrays. This solved related process implementation challenges, achieved zero buoyancy balance across the entire array, completed the development of a Φ16mm diameter array and low-speed towing tests on a lake, and successfully accumulated engineering experience. These technologies have significant application value in the field of underwater acoustic sensing.

[0046] It is understood that, for those skilled in the art, any equivalent substitutions or modifications to the technical solutions and inventive concepts of this utility model should fall within the protection scope of the appended claims.

Claims

1. A reduced-vibration module for a towed array of ultra-fine optical fibers, characterized in that, The utility model relates to a kind of flexible optical cable support structure, including: Two array connectors (1) are respectively arranged at the two ends of the vibration isolation module, and a sheath (5) is installed between the two array connectors (1); Two force-bearing members (2) are fixedly installed on the corresponding array connector (1), and the other end of the force-bearing member (2) extends into the sheath (5) and is provided with a force-bearing rope hole (9) and an elastic rope hole (10); A plurality of force-bearing skeletons (4) are arranged at equal intervals along the axial direction of the inner cavity of the sheath (5) to support the sheath (5); An elastic rope (7) is arranged in the sheath (5), one end of the elastic rope (7) is fixed to one of the force-bearing members (2) through the elastic rope hole (10), and the other end of the elastic rope (7) sequentially penetrates through each of the force-bearing skeletons (4) and is fixed to the elastic rope hole (10) of the other force-bearing member (2); A force-bearing rope (3) is arranged in the sheath (5), the force-bearing rope (3) is divided into two strands which are arranged along the outer wall of each of the force-bearing skeletons (4) and then penetrate into the force-bearing rope hole (9) of the other force-bearing member (2) and are combined into one strand; and A flexible optical cable (6) is arranged in the sheath (5) and along the outer wall of each of the force-bearing skeletons (4), and the flexible optical cable (6) is connected to the corresponding array connector (1) at both ends.

2. The ultra-fine pitch fibered tow line array de-isolation module of claim 1, wherein: The fixed end of the force-bearing member (2) and the array connector (1) is provided with a cylindrical platform (14), the cylindrical platform (14) is embedded in the array connector (1) and is fixed by a compression ring (8).

3. The ultra-compact erbium-doped fiber laser source of claim 1, wherein: An elastic rope passing hole (12) is formed in the center of each of the force-bearing skeletons (4) for the elastic rope (7) to pass through, force-bearing rope laying grooves (11) are symmetrically formed on the outer wall of the force-bearing skeleton (4) for the force-bearing rope (3) to lay and run, and a plurality of flexible optical cable mounting grooves (13) are uniformly distributed on the outer wall of the force-bearing skeleton (4) between the two force-bearing rope laying grooves (11) for the flexible optical cable (6) to lay and run.

4. The ultra-compact erbium-doped fiber laser source of claim 1, wherein: The force-bearing skeleton (4) is made of glass beads.

5. The ultra- fine pitch fibered towed array de- vibration module of claim 1, wherein: The array connector (1) and the force-bearing member (2) are made of TC4 titanium alloy material, have a tensile strength of not less than 895 MPa and a specified residual elongation stress of not less than 830 MPa.

6. The ultra-compact erbium-doped fiber laser source of claim 1, wherein: The force-bearing rope (3) is a flat wear-resistant rope, and has a breaking tensile force of not less than 150 kg.

7. The ultra-compact erbium-doped fiber laser source of claim 1, wherein: The sheath (5) is made of PU material and has a tubular structure, and the outer diameter is not more than Φ15 mm.

8. The ultra- fine pitch fibered towed array de -vibration module of claim 1, wherein: The inner cavity of the sheath (5) is filled with a low-density solid glue, and the density after curing is not more than 0.90 g / cm 3 .

9. The ultra-compact erbium-doped fiber laser source of claim 1, wherein: The flexible optical cable (6) is a metal flexible armored tube coated with iron fluoride, and a pair of thin-diameter anti-microbend optical fibers are arranged in the flexible optical cable (6).

10. The submillimeter diameter optical fiber towed array de-isolation module of claim 1, wherein: The elastic rope (7) is an ultra-thin single-coding nylon rope with a diameter of Φ2 mm, and the elongation under low drag speed is not more than 15%.

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