Nested central tube type directly-buried optical cable for detection

Abstract

The utility model discloses a nested central tube type directly-buried optical cable for detection, which comprises a circular sleeve formed by extrusion molding of high polymer materials, a plurality of optical units are embedded in the sleeve, and at least four sensing optical units are included; the cable also comprises an outer sheath which is wrapped outside the sleeve and the reinforcing member and is used for providing overall protection. The sensing light units are arranged in the sleeve, when the optical cable is subjected to external force, the size and frequency of the external force can be sensed in real time, the position and intensity distribution of the external force are judged through the stress response difference of different sensing light units, and accurate monitoring of environmental stress changes is achieved. The optical cable is compact in structure and good in flexibility, has communication and real-time sensing functions, is suitable for structural health monitoring and optical cable laying application in a complex environment, and has high practical value.

Description

Technical Field

[0001] This utility model relates to an optical cable, specifically a nested central tube type direct-buried optical cable for detection. Background Technology

[0002] Traditional optical cables are primarily used for transmitting communication signals, and their structure typically includes fiber optic units, reinforcement components, and an outer sheath. However, in complex environments (such as underground installations, submarine deployments, or areas susceptible to external damage), optical cables may be damaged due to mechanical stress, compression, vibration, or human-caused damage, leading to communication interruptions. Furthermore, traditional optical cables cannot detect the location, intensity, and frequency of external forces in real time, making it difficult to provide timely warnings or pinpoint fault locations, increasing maintenance difficulty and costs.

[0003] Currently, some technologies have attempted to integrate sensing functions into optical cables, such as using distributed fiber optic sensing technologies (DAS, DTS, etc.) to monitor parameters such as strain and temperature. However, these solutions typically suffer from the following problems:

[0004] A single sensing fiber cannot accurately distinguish the direction and location of external forces, resulting in fuzzy monitoring data.

[0005] Most sensing optical cables use a stranded or ribbon structure, resulting in uneven distribution of sensing units, which affects the ability to spatially identify external forces.

[0006] Reinforcing components are mostly made of metal materials (such as steel wire), which can improve strength, but are prone to corrosion and may interfere with sensing signals; while the problem of balancing strength and flexibility of non-metallic reinforcing components has not yet been effectively solved. Summary of the Invention

[0007] To address the aforementioned issues, this invention provides a nested central tube type direct-buried optical cable for detection. By symmetrically arranging multiple optical sensing units and combining them with non-metallic reinforcing components, it achieves an integrated design of high-precision external force monitoring and high-reliability communication transmission. This structure can not only sense the magnitude, frequency, and location distribution of external forces in real time, but also adapt to the long-term use requirements in complex environments.

[0008] This utility model is achieved through the following technical solution: a nested central tube type direct-buried optical cable for detection, comprising:

[0009] The circular sleeve is a hollow structure formed by extruding polymer materials, and its interior is used to accommodate multiple optical units.

[0010] Multiple optical units are embedded inside the sleeve for transmitting communication and monitoring signals;

[0011] The outer sheath covers the outside of the sleeve and reinforcement to provide overall protection;

[0012] The optical unit includes at least four sensing optical units, which are arranged inside the sleeve to sense the magnitude and frequency of external forces when the optical cable is subjected to external forces, and to identify the location and intensity distribution of external forces based on the differences in the force response of different sensing optical units.

[0013] As a preferred technical solution, the optical unit includes four optical sensing units, which are arranged equidistantly at 90-degree angles inside the sleeve.

[0014] As a preferred technical solution, the circular sleeve is made of polyethylene or polypropylene.

[0015] As a preferred technical solution, the optical sensing unit is a distributed fiber optic sensor, which has the function of real-time sensing of stress changes.

[0016] As a preferred technical solution, the sleeve is further filled with reinforcing members.

[0017] As a preferred technical solution, the reinforcing member is made of high-strength non-metallic fiber material.

[0018] The beneficial effects of this utility model are: by symmetrically arranging at least four optical sensing units (such as distributed optical fiber sensors) inside a circular sleeve and adopting an equidistant 90-degree distribution design, this utility model enables the optical cable to accurately identify the magnitude, direction, frequency and location of the external force through the strain differences of different sensing units when subjected to external force, thereby achieving spatially distributed real-time monitoring and greatly improving fault location and environmental perception capabilities.

[0019] This invention uses a circular sleeve made of polymer materials (such as polyethylene or polypropylene) extruded and combined with high-strength non-metallic fiber reinforcement. While ensuring the flexibility and bendability of the optical cable, it provides excellent tensile, compressive and impact resistance, making it suitable for long-term stable operation in complex environments. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. 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 overall structure of this utility model;

[0022] Figure 2 This is a cross-sectional schematic diagram of the present invention;

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Outer sheath; 2. Tube; 3. Optical unit; 4. Reinforcing component. Detailed Implementation

[0025] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0026] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features for a similar purpose, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0027] like Figure 1 and Figure 2 As shown, the present invention provides a nested central tube type direct-buried optical cable for detection, which has a reasonable structural design and is suitable for scenarios that require synchronous transmission of communication signals and have external force monitoring functions. Its specific structure and implementation method are described below.

[0028] The central tube optical cable includes a circular sleeve 2 extruded from a polymer material. The circular sleeve 2 has a hollow structure and is used to house the optical units 3, such as communication optical fibers and sensing optical fibers. The polymer material is preferably polyethylene or polypropylene. These materials not only have good insulation and corrosion resistance, but also good mechanical strength and flexibility, which can effectively resist the erosion of the external environment and improve the service life and adaptability of the optical cable.

[0029] Multiple optical units 3 are uniformly arranged inside the circular sleeve 2, including at least four sensing optical units 3. The optical units 3 achieve spatial stability by being tightly embedded in the sleeve 2, preventing displacement or fiber strain relaxation, thereby improving the structural stability and transmission reliability of the optical cable. The sensing optical units 3 preferably employ distributed optical fiber sensors, which can achieve real-time monitoring of external stresses on the optical cable using technologies such as Bragg gratings (FBG), optical time domain reflectance (OTDR), or phase-sensitive distributed sensing (DVS). This type of distributed optical fiber sensor has sensing nodes uniformly distributed along the fiber length, enabling continuous and dynamic sensing of stress changes along the line, and possesses high sensitivity and high spatial resolution.

[0030] In this embodiment, four optical sensing units 3 are arranged at equal intervals of 90 degrees near the inner wall of the sleeve 2, forming a ring-shaped sensing structure in a circumferentially distributed manner. This arrangement is beneficial for determining the direction and location of external forces by the difference in response values ​​between the four sensing optical fibers when the optical cable is subjected to external forces from different directions. This enhances the sensitivity of the optical cable to external interference and improves its positioning accuracy, meeting the needs of structural health monitoring and safety early warning.

[0031] To further enhance the mechanical properties of the optical cable, a reinforcing member 4 is also installed inside the circular sleeve 2. The reinforcing member 4 is made of high-strength non-metallic fiber material, preferably aramid fiber (such as Kevlar) or glass fiber. This type of material has good flexibility and extremely high tensile strength, enabling it to withstand mechanical loads during installation and construction, such as tension and bending, without significantly increasing the weight and flexibility of the optical cable. The reinforcing member 4 is continuously installed along the length of the optical cable, improving the stability and reliability of the entire optical cable in harsh construction or usage environments.

[0032] The outermost layer of the optical cable is the outer sheath 1, which covers the circular sleeve 2 and its reinforcing member 4, providing overall protection. The outer sheath 1 is made of high-molecular materials that are UV-resistant, wear-resistant, and corrosion-resistant, such as low-smoke halogen-free polyolefin or flame-retardant polyvinyl chloride, which can effectively resist the influence of environmental humidity, acid and alkali corrosion, mechanical impact, and other factors on the internal structure. In addition, the outer sheath 1 also serves to integrate the structure and fix the relative positions of the internal components, preventing the internal optical fibers from shifting or local stress concentration due to temperature changes, vibration, or bending.

[0033] In practical applications, this optical cable can be laid using conventional methods, such as air-blowing deployment and traction laying. Once the optical cable is laid and put into use, if abnormal mechanical stress occurs in the external environment, such as ground subsidence, equipment vibration, external impact, or structural fatigue, the optical sensing unit 3 inside the optical cable can monitor stress changes in real time and generate data output. After being analyzed by the back-end acquisition device, the magnitude, frequency, and location of the stress event can be determined, thereby realizing intelligent perception and early warning of the laying environment or the monitored structure.

[0034] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions conceived without inventive effort should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope defined in the claims.

Claims

1. A nested central tube type direct-buried optical cable for detection, characterized in that, include: The circular sleeve (2) is a hollow structure formed by extrusion of polymer material, and the interior is used to accommodate multiple optical units (3); Multiple optical units (3) are embedded inside the sleeve (2) for communication and monitoring signal transmission; The outer sheath (1) covers the outside of the sleeve (2) and the reinforcing member (4) to provide overall protection; The optical unit (3) includes at least four sensing optical units (3) arranged inside the sleeve (2) to sense the magnitude and frequency of external force when the optical cable is subjected to external force, and to identify the location and intensity distribution of external force based on the differences in the force response of different sensing optical units (3).

2. The nested central tube type direct-buried optical cable for detection according to claim 1, characterized in that: The optical unit (3) includes four optical sensing units (3), which are arranged in the sleeve (2) at equal intervals of 90 degrees.

3. The nested central tube type direct-buried optical cable for detection according to claim 1, characterized in that: The circular sleeve (2) is made of polyethylene or polypropylene.

4. The nested central tube type direct-buried optical cable for detection according to claim 1, characterized in that: The optical sensing unit (3) is a distributed optical fiber sensor, which has the function of real-time sensing of stress changes.

5. The nested central tube type direct-buried optical cable for detection according to claim 1, characterized in that: The sleeve (2) is also filled with a reinforcing member (4).

6. The nested central tube type direct-buried optical cable for detection according to claim 5, characterized in that: The reinforcing member (4) is made of high-strength non-metallic fiber material.

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