Sensor, system, and sensing method

Abstract

An object of the present disclosure is to wire an optical fiber for sensing by a simple method.SOLUTION: An optical fiber sensor 200 of the present disclosure includes a deformable optical fiber coating 30 formed in a flat plate shape extending in a predetermined direction, and one or more optical fibers 20 embedded in the optical fiber coating 30.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to fiber optic sensing technology. [Background technology]

[0002] Optical fiber sensing methods have been known for some time, in which an optical fiber is wired in contact with an object to be measured and the state of the object is measured. For example, Non-Patent Document 1 discloses a technique for measuring the dynamic strain of an optical fiber by irradiating a test light onto the optical fiber and measuring the time change in the backscattered light. By measuring the state of the optical fiber, the state of the object to be measured can be measured.

[0003] Furthermore, studies are being conducted on treating communication optical fiber networks as sensors to measure environmental information around the cables. In particular, in order to reduce the effort and cost of laying new optical fiber for optical fiber sensing, studies are being conducted on utilizing communication optical fiber already laid in cities for sensing (see Non-Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7315009 [Non-patent literature]

[0005] [Non-Patent Document 1] “Advances in distributed vibration sensing for optical communication fiber state visualization”, Optical Fiber Technology, Vol.57, 102263. 2020 [Non-patent document 2] "Smart Engineering / Maintenance Initiatives Aiming for Operational Innovation," Business Communication 2022 Vol. 59 No. 4 [online], [Retrieved June 11, 2024], Internet<URL:https: / / www.bcm.co.jp / site / 2022 / 04 / ntt-as / 2204-ntt-as-01-06.pdf> Summary of the Invention [Problem to be solved by the invention]

[0006] However, when wiring optical fibers for sensing, the measurement results and accuracy can vary significantly depending on how they are laid and how they are contacted during wiring. For this reason, advanced technology is required to wire optical fibers for sensing, and there has been a demand for a simpler method for wiring optical fibers for sensing.

[0007] In order to solve the above problems, an object of the present disclosure is to provide a simple method for wiring optical fibers for sensing. [Means for solving the problem]

[0008] To achieve the above object, the sensor, system, and sensing method disclosed herein employ a technique in which a plurality of optical fibers are embedded in a deformable flat plate portion formed in a flat plate shape extending in a predetermined direction.

[0009] Specifically, the sensor of the present disclosure comprises: a deformable flat plate portion formed in a flat plate shape extending in a predetermined direction; and one or more optical fibers embedded in the flat plate portion.

[0010] Furthermore, the flat plate portion may be connected to each other at ends thereof that are positioned in a direction different from the direction in which the one or more optical fibers extend, thereby enabling the flat plate portion to be wrapped around the object to be measured.

[0011] Furthermore, the one or more optical fibers may be spirally wound around the object to be measured.

[0012] The extending direction of the one or more optical fibers changes at a predetermined cycle within the flat plate portion, A plurality of arbitrary spirals may be formed when wound around the object to be measured.

[0013] The flat plate portion has a predetermined thickness, The one or more optical fibers may be embedded in the flat plate portion in a thickness direction thereof to form a plurality of layers.

[0014] Furthermore, the rate of the spiral, which indicates the number of revolutions of the spiral per unit distance along the measurement object, may be set to a value exceeding one revolution in the distance resolution of strain distribution measurement.

[0015] Specifically, the system of the present disclosure includes: The above sensor; an optical sensing device for acquiring light scattering characteristics in an optical fiber; Equipped with.

[0016] Specifically, the sensing method of the present disclosure includes: The method includes embedding one or more optical fibers in a deformable flat plate portion formed in a flat plate shape extending in a predetermined direction.

[0017] and a step of winding the one or more optical fibers around the measurement object by connecting ends of the flat plate portion that are positioned in a direction different from the extending direction of the one or more optical fibers. and obtaining light scattering characteristics in the one or more optical fibers using a light sensing device.

[0018] The above disclosures can be combined as much as possible. [Effects of the Invention]

[0019] According to the present disclosure, optical fibers for sensing can be wired in a simple manner. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram illustrating an overview of an optical fiber sensing system according to the present disclosure. [Figure 2] 1A and 1B are diagrams illustrating an overview of optical fiber sensing using an optical fiber sensor according to an embodiment of the present disclosure. [Figure 3] 1A and 1B are diagrams illustrating an optical fiber sensor according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a view of the optical fiber sensor as seen from the longitudinal direction of the optical fiber. [Figure 5] FIG. [Figure 6] 1A and 1B are diagrams illustrating how the optical fiber sensor is wound around a measurement target. [Figure 7] FIG. 2 is a view of a measurement target around which an optical fiber sensor is wound, viewed from the longitudinal direction of the optical fiber. [Figure 8] 10A and 10B are diagrams illustrating a modified example of the optical fiber sensor. [Figure 9] 10A and 10B are diagrams illustrating a manner in which a modified optical fiber sensor is wound around a measurement target. [Figure 10] 1A and 1B are diagrams illustrating forces acting on an optical fiber sensor. [Figure 11] 10A and 10B are diagrams illustrating a modified example of the optical fiber sensor. [Figure 12] 1A and 1B are diagrams illustrating forces acting on an optical fiber sensor. [Figure 13] 10A and 10B are diagrams illustrating a process for winding an optical fiber sensor around a measurement object. [Figure 14] FIG. 10 is a diagram illustrating an overview of an optical fiber sensing system according to a second embodiment of the present disclosure. [Figure 15] 1A and 1B are diagrams illustrating an application example of measuring the shape of a measurement object using an optical fiber. [Figure 16] FIG. 1 illustrates a related optical fiber system. [Figure 17] 10A and 10B are diagrams illustrating an optical fiber coating according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings indicate the same components.

[0022] [Outline of Optical Fiber Sensing] An optical fiber sensing system 500 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 and 2 . The optical fiber sensing system 500 includes an optical fiber sensing device 10 and an optical fiber 20. As shown in FIG. 2 , a plurality of optical fibers 20 are embedded in an optical fiber coating 30 to form a sensor, and the optical fiber sensor 200 is wound around a measurement target 40. Note that for simplicity of illustration, FIGS. 1 and 2 show a state in which the optical fiber sensing device 10 is connected to one optical fiber 20. However, in reality, a plurality of optical fibers 20 are connected to the optical fiber sensing device 10. However, the scope of the present disclosure is not limited thereto, and a plurality of optical fiber sensing devices 10 may be provided corresponding to the plurality of optical fibers 20, respectively. Furthermore, the scope of the present disclosure is not limited to the provision of a plurality of optical fibers 20, as long as one or more optical fibers 20 are provided.

[0023] Specifically, the optical fiber sensing system 500 of the present disclosure includes: an optical fiber sensor 200 in which a plurality of optical fibers 20 are embedded in an optical fiber coating 30; an optical sensing device (10) for acquiring light scattering characteristics in an optical fiber (20); Equipped with.

[0024] In the optical fiber sensing system 500, an optical fiber sensing device 10 is used to input test light such as pulse or CW (Continuous Wave) into an optical fiber 20, and observe the backscattered light generated within the optical fiber 20. Based on the observation results of such backscattered light, the optical fiber sensing system 500 can measure the state of an object in contact with the optical fiber 20. The optical fiber sensing device 10 functions as an "optical sensing device."

[0025] Specifically, the state of the optical fiber 20 changes when a disturbance (bending, temperature change, strain, excitation, etc.) is applied, and the state of the backscattered light also changes in accordance with this state change. In other words, by observing the state change of the backscattered light, it is possible to observe the state change of the optical fiber 20, that is, the state of the disturbance applied to the optical fiber. For this reason, the optical fiber sensing system 500 uses a method in which the optical fiber 20 is regarded as a sensor and the backscattered light is observed to measure or estimate the disturbance applied to the optical fiber 20 (bending, temperature change, strain change, vibration, etc.). Here, the disturbance applied to the optical fiber 20 includes a disturbance caused by a change in the state of an object that is in direct or indirect contact with the optical fiber 20.

[0026] In this way, the optical fiber sensing system 500 estimates not only the state of the optical fiber cable itself containing the optical fiber 20, but also the state of the environment surrounding the optical fiber 20. It is expected that this information regarding the state of the environment surrounding the optical fiber 20 will be used for various purposes (see Non-Patent Document 2).

[0027] Note that the disturbances that can be measured depend on the measurement method and the type of scattered light being observed. For example, the optical fiber sensing device 10 may be an OTDR (Optical Time-Domain Reflectometer) that inputs an optical pulse into the optical fiber 20 and extracts the scattered light. Furthermore, the measurement method for optical fiber sensing may be an OFDR (Optical Frequency Domain Reflectometry) that uses the coherence of laser light, or a BOTDR (Brilouin Optical Time Domain Reflectometry) that receives and analyzes Brillouin scattered light to continuously measure the strain of the optical fiber.

[0028] Furthermore, the optical fiber sensing system 500 may be a DAS (Distributed Antenna System) that expands the communication area by distributing radio waves received from a base station via optical cables.

[0029] Furthermore, the scattered light to be observed may be any of Rayleigh scattered light, Brillouin scattered light, Raman scattered light, etc. In particular, the optical fiber sensing device 10 may be a Raman OTDR.

[0030] In the present disclosure, the optical fiber sensor 200, in which a plurality of optical fibers 20 are embedded in the optical fiber coating 30, is wound around the measurement object 40, so that even the shape of the measurement object 40 can be measured. Specifically, by using a plurality of optical fibers 20, the shape of the measurement object 40 can be measured in a pseudo manner similar to when a multi-core fiber is used. Details of the shape measurement of the measurement object 40 will be described later.

[0031] [Optical fiber sensor] Next, the configuration of an optical fiber sensor 200 according to an embodiment will be described with reference to FIGS. 3 and 4. The optical fiber sensor 200 is configured by embedding and integrating three or more optical fibers in an optical fiber coating 30 formed in a flat plate shape. The optical fiber coating 30 extends in a predetermined direction (the left-right direction in the figure) and is deformable. The optical fiber coating 30 functions as a "flat plate portion" in the present disclosure. By covering a measurement target 40 such as a communication cable, a wire rope, or a pipe with the optical fiber sensor 200 configured in this manner, optical fiber sensing can be performed with standardized specifications for any object. In other words, the optical fiber sensor 200 functions as a "sensor" in the present disclosure. The number of optical fibers 20 can be any number as long as it is plural, but providing four or more optical fibers can improve the accuracy of the sensor.

[0032] The material of the optical fiber coating 30 may be metal or resin. The optical fiber 20 does not necessarily have to be embedded in the optical fiber coating 30, but may be inserted into a pipe or the like that is already embedded in the optical fiber coating 30. The optical fiber 20 embedded in or inserted into the optical fiber coating 30 may be in the form of a bare wire. However, the present disclosure is not limited to this, and various forms of the optical fiber 20, such as a cable or a tube, may be embedded in or inserted into the optical fiber coating 30.

[0033] 3 and 4, the optical fibers 20 are embedded in the optical fiber coating 30 so as to be arranged at predetermined intervals in the vertical direction. The optical fiber coating 30 has a predetermined thickness. When the optical fiber sensor 200 is wrapped around the measurement object, the ends (upper end and lower end) of the optical fiber coating 30 in the vertical direction are connected to each other. In other words, the optical fiber sensor 200 can be wrapped around the measurement object 40 by connecting the ends of the optical fiber coating 30 located in a direction different from the extending direction of the multiple optical fibers 20 to each other.

[0034] [Wrapping of optical fiber sensor] Next, the manner in which the optical fiber sensor 200 is wound around the measurement object 40 will be described with reference to Fig. 5 to Fig. 7. Fig. 5 is a diagram showing the appearance of the measurement object 40. The measurement object assumed in this embodiment is a pipe, a cable, or a tower-like structure.

[0035] 6 shows an embodiment in which the optical fiber sensor 200 is wound around the measurement target 40. The joint 31 is a connection point between the ends of the optical fiber coating 30. Various connection methods are possible, and the ends may be mechanically connected, or may be bonded. By connecting the ends in this manner, the optical fibers 20 are arranged at equal intervals in the circumferential direction, as shown in FIG. 7.

[0036] According to this embodiment, for example, when no twisting stress acts, the state (shape) of the measurement object 40 can be grasped suitably.

[0037] [Modification of optical fiber sensor] The scope of the present disclosure is not limited to embedding the optical fiber 20 in the optical fiber coating 30 parallel to the extending direction of the optical fiber coating 30, as in the above embodiment. For example, as shown in Fig. 8, the optical fiber 20 may be embedded in the optical fiber coating 30 so that the extending direction of the optical fiber 20 within the optical fiber coating 30 changes at a predetermined period.

[0038] This allows the optical fibers 20 to be stretched at a predetermined angle relative to the axial direction of the measurement object 40. That is, when the optical fiber sensor 201 shown in Fig. 8 is wound around the measurement object 40, a spiral is formed as shown in Fig. 9. In other words, when the optical fiber sensor 200 is wound around the measurement object 40, the multiple optical fibers 20 form a spiral.

[0039] Ideally, the optical fiber 20 would be embedded in the optical fiber coating 30 at a uniform angle. However, if the measurement object 40 is long, forming a single spiral around the entire measurement object 40 would require embedding the optical fiber 20 in the optical fiber coating 30 at a very small angle. In this case, the spiral rate (revolutions / m) becomes very small, and distortion due to the spiral becomes large. For this reason, in this embodiment, the angles are reversed at several points in the optical fiber coating 30, that is, the extension direction of the optical fiber 20 is changed at a predetermined cycle, thereby forming multiple arbitrary spirals.

[0040] Furthermore, at the discontinuous points of the spiral, the angle change is not abrupt, but is gently bent at a bending radius R, thereby enabling the spiral to be formed without loss.

[0041] The optical fiber sensor 201 can be wound around the measurement object 40 so that the spiral rate (revolutions / m) is also an arbitrary value. Here, the spiral rate may be set to a small value of approximately one revolution or less in terms of the distance resolution (m) of the strain distribution measurement in order to measure the spiral state. On the other hand, since the strain caused by the spiral decreases as the rate increases, the rate may be set to a value that strikes a balance.

[0042] With this spiral structure, even if stress is applied to the optical fiber 20 in the direction indicated by the arrow in Figure 10 due to shear deformation of the object 40, causing twisting of the optical fiber 20, it is possible to detect the twist and estimate the shape in the same way as with shape sensing using a spiral multi-core. Furthermore, if the shape of the optical fiber coating 30 is known, the shape of the object 40 can also be determined, and strain and stress can be detected by using techniques such as Brillouin measurement. When measuring temperature, it is possible to artificially increase the spatial resolution by increasing the spin rate.

[0043] 11, the shape of the measurement object 40 may be measured using an optical fiber sensor 202 having a two-layer spiral structure. In other words, the multiple optical fibers 20 may be embedded in the optical fiber coating 30 so as to form multiple layers in the thickness direction of the optical fiber coating 30. By forming two layers in this way, as shown by the arrows in FIG. 12, when the optical fiber is locally bent or stressed (when a force is applied in a direction from the surface toward the center of the measurement object 40), the local deformation can be measured. The multiple optical fibers 20 may be embedded in the optical fiber coating 30 so as to form three or more layers in the thickness direction of the optical fiber coating 30.

[0044] 11 and 12, the spiral configuration method and rate concept are the same as those described above. Also, if the shape of the optical fiber sensor 202 is known, the shape of the measurement target 40 can also be determined, and similarly, strain and stress can be measured by Brillouin measurement or the like.

[0045] [Workflow] Next, the process of winding the optical fiber sensor 200 around the measurement object 40 will be described with reference to the flowchart of FIG.

[0046] Specifically, the sensing method of the present disclosure includes: a step of embedding a plurality of optical fibers 20 in a deformable optical fiber coating 30 formed in a flat plate shape extending in a predetermined direction; a step of winding the plurality of optical fibers 20 around the measurement object 40 by connecting ends of the optical fiber coatings 30 located in a direction different from the extending direction of the plurality of optical fibers 20; a step of acquiring light scattering characteristics in a plurality of optical fibers 20 using an optical fiber sensing device 10; Includes.

[0047] First, the user embeds the optical fiber 20 in the optical fiber coating 30 (step S1). As described above, a pipe may be embedded in the optical fiber coating 30 in advance, and the optical fiber 20 may be inserted into the pipe.

[0048] The user wraps and fixes the optical fiber sensor 200, in which the optical fiber 20 is embedded, around the measurement target 40 (step S2).

[0049] The user uses the optical fiber 20 and the optical fiber sensing device 10 to perform desired optical fiber sensing (step S3).

[0050] [Second embodiment] Next, an optical fiber sensing system 501 according to the second embodiment will be described with reference to Fig. 14 and Fig. 15. As shown in Fig. 14, the optical fiber sensing system 501 includes a processor 50 in addition to the components included in the optical fiber sensing system 500 according to the first embodiment. The optical fiber sensing system 501 uses an optical fiber 20 to measure the shape of the measurement target 40. The processor 50 is configured to be able to calculate various physical quantities using the results of the shape measurement.

[0051] In the optical fiber sensing system 501, the shape of the measurement object 40 is measured using a method similar to that of shape measurement using a multi-core fiber. Specifically, the degree of distortion of each core in the cross sections of a plurality of optical fibers 20 is compared, and it can be determined that the greater the distortion, the more bent the object is. In this case, the shape of the measurement object 40 may be measured using the method disclosed in Patent Document 1.

[0052] 15 shows an application example of the measurement results of measuring the shape of the measurement object 40 using multiple optical fibers 20. First, the optical fiber sensing system 501 measures the shape of the optical fibers 20 (optical fiber sensors 200, 201, 202) attached along the shape of the measurement object 40 (step S11). The arithmetic processing device 50 may calculate the deformation of the measurement object 40 using the shape of the optical fibers 20 (step S12). The arithmetic processing device 50 may also calculate the stress distribution on the measurement object 40 based on the deformation of the measurement object 40 (step S13). Furthermore, the arithmetic processing device 50 may detect stress concentration on the measurement object 40 and identify the stress concentration location (step S14).

[0053] [effect] Next, the effects of the present disclosure will be described in comparison with a related optical fiber sensing system 500A shown in FIG.

[0054] First, when wiring optical fiber for optical fiber sensing, the measurement results and accuracy can vary significantly depending on factors such as how the fiber is laid, the contact method, and the condition of the optical fiber coating. This requires highly advanced know-how and technology for fiber wiring. In particular, optical fiber for communication is not wired for optical fiber sensing, so the measurement results and accuracy can vary significantly depending on the condition of the target communication fiber. For this reason, it is necessary to check the condition of the optical fiber for communication in advance, as this will affect the function, performance, and usability of optical fiber sensing.

[0055] In contrast, in the present disclosure, optical fiber sensors 200, 201, and 202 can be wrapped around a measurement target 40, such as a communication cable, wire rope, or pipe, in a post-process, thereby enabling optical fiber sensing with standardized specifications for any measurement target 40. This makes it possible to suppress changes in sensing performance and accuracy due to the wiring of the optical fiber 20 and achieve consistent performance. Furthermore, by fixing the structure of the optical fiber coating 30 and the type of optical fiber 20 used, it is possible to turn objects of any shape into sensors under the same conditions. Furthermore, any object already existing in the market, such as a communication fiber, can be turned into a sensor medium with consistent performance.

[0056] Next, measurements using existing strain measurement optical fiber sensing cables use single-mode fibers that only measure strain, making it difficult to directly measure the shape or bending of a structure.

[0057] In contrast to this, according to the present disclosure, the optical fiber sensors 200, 201, and 202 in which a plurality of (three or more) optical fibers 20 are embedded can be used to measure the shape of the measurement object 40 in the same way as with a multi-core fiber.

[0058] 16, when a single optical fiber 20 is embedded in an optical fiber coating 30A for measurement, it is necessary to insert the optical fiber into a rigid pipe to prevent the optical fiber 20 from bending significantly, or to fill the pipe with liquid to suppress twisting of the optical fiber 20. However, depending on the shape of the measurement object 40, it may be necessary to bend the optical fiber 20 (and the pipe). Also, there are measurement objects 40 with shapes that make twisting of the optical fiber 20 unavoidable.

[0059] In such a case, it is necessary to measure the shape of the measurement object 40 and the optical fiber to compensate for the large bending or twisting of the optical fiber to be used as a sensor. However, it is difficult to perform shape measurement using a multi-core fiber to compensate for the twisting. This is because, in order to perform shape measurement, it is necessary to wire the multi-core fiber without twisting.

[0060] In contrast, according to the present disclosure, by using optical fiber sensors 200, 201, 202 in which multiple (three or more) optical fibers 20 are embedded, particularly in a spiral structure, optical fiber sensing can be performed in a pseudo manner, similar to using a multi-core fiber, regardless of the fiber type or fiber state, even when twisting or bending occurs.

[0061] [Third embodiment] The configuration of an optical fiber coating 30 according to the third embodiment of the present disclosure will be described with reference to FIG.

[0062] In the above configuration, when measuring the shape of an object in detail, such as the shape of an optical fiber coating (e.g., a spiral shape), the span length S must be equal to or greater than the fiber measurement resolution. Note that the span length S refers to the distance along the object to be measured between points where the direction of extension of the fiber spiral changes.

[0063] Here, the newly added sensor part may not be as long as the communication fiber. For example, the sensor part may be several meters long. In contrast, OTDR, which is a common sensing method for vibration, strain, etc., cannot measure with a measurement resolution of several meters or less. For this reason, even if the above-mentioned optical fiber coating 30 is wrapped around the object to be measured without considering the design of each part, it is difficult to measure with high resolution.

[0064] On the other hand, there are many cases where the shape of the object to be measured is already known, in which case there is no need to estimate the shape from sensing. Therefore, there is no need to measure the shape of the optical fiber coating in detail. In addition, there is no need to set the span length S to a large value, and it can be set to any value. Furthermore, the number of fibers can be multiple or one.

[0065] Even in this case, if the coupling mode of the spiral fiber is designed as follows, the effective sensing resolution of the object to be measured can be improved to be equal to or greater than the resolution of the sensing measurement method (OTDR, etc.).

[0066] Specifically, if the radius of the sensor portion to be applied is r, its circumference is 2πr, and hereinafter the length of the circumference will be represented as R (R = 2πr). If the length of one span of the spiral is S, the actual length L of the optical fiber 20 in one span can be expressed as L = √(R^2 + S^2). In this case, for example, for a portion where the distance along the object to be measured between points where the extension direction of the fiber spiral changes is S, the sensor unit will be made up of optical fiber 20 of length L. In other words, between points where the extension direction of the fiber spiral changes (using the distance along the object to be measured between the change points as a unit), L / S = √((R / S)^2 + 1) of fiber will be included.

[0067] Furthermore, if the length of the entire sensor unit is M, then ML / S is the fiber length. Here, if the measurement resolution is dz, then with a fiber in a normal cable, measurements can be made separately at the point M / dz. On the other hand, with the optical fiber coating 30 according to this embodiment, measurements can be made at the point ML / Sdz, and the number of points that can be measured separately increases by L / S times. Because the measurement portion of M is measured at the point ML / Sdz, the resolution is effectively reduced to S / L.

[0068] For example, if the radius of the sensor is 10 cm, the circumference will be R ≒ 0.628 m. If the span S = 1 cm, then L = √((0.628)^2 + 0.01^2) = 0.628 m. In this case, S / L = 0.0159, L / S = 62.8, and the number of points that can be separated is approximately 63 times.

[0069] For example, when measuring a 10m distance with an OTDR of 20ns (resolution 2m), only 5 points can be measured. In contrast, this embodiment makes it possible to measure approximately 314 points. In other words, since it is possible to measure a 10m object at 314 points, this is equivalent to a measurement with an effective resolution of 3.18cm (≒20×S / L=20×0.0159).

[0070] Thus, according to this embodiment, by making the span small, it is equivalent to measuring the object with higher resolution, and the object can be measured in detail using the attached sensor unit.

[0071] The device of the present invention can also be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a network. The program of the present disclosure is a program for causing a computer to realize each function of the device according to the present disclosure, and a program for causing a computer to execute each procedure of the method executed by the device according to the present disclosure. [Explanation of symbols]

[0072] 10: Optical fiber sensing device 20: Optical fiber 30, 30A: Optical fiber coating 31:Joining part 40: Measurement target 50: Processing unit 200, 201, 202: Optical fiber sensors 500, 501, 500A: Optical fiber sensing system

Claims

1. a deformable flat plate portion formed in a flat plate shape extending in a predetermined direction; and one or more optical fibers embedded in the flat plate portion. Sensor.

2. The flat plate portion can be wound around the object to be measured by connecting ends of the flat plate portion that are positioned in a direction different from the direction in which the one or more optical fibers extend. The sensor of claim 1 .

3. The one or more optical fibers form a spiral shape when wrapped around the measurement object. The sensor of claim 2 .

4. the extending direction of the one or more optical fibers changes at a predetermined period within the flat plate portion; A plurality of arbitrary spirals are formed in a state where the spiral is wound around the object to be measured. The sensor of claim 3 .

5. The flat plate portion has a predetermined thickness, The one or more optical fibers are embedded in the flat plate portion so as to form a plurality of layers in the thickness direction of the flat plate portion. The sensor of claim 4.

6. a rate of the spiral, which indicates a rotation of the spiral per unit distance along the measurement object, is set to a value exceeding one rotation in the distance resolution of strain distribution measurement; The sensor of claim 3 .

7. A sensor according to any one of claims 1 to 6; an optical sensing device for acquiring light scattering characteristics in an optical fiber; Equipped with system.

8. The method includes embedding one or more optical fibers in a deformable flat plate portion formed in a flat plate shape extending in a predetermined direction. Sensing method.

9. a step of winding the one or more optical fibers around the measurement object by connecting ends of the flat plate portion that are located in a direction different from an extending direction of the one or more optical fibers; and acquiring light scattering characteristics in the one or more optical fibers using an optical sensing device. The sensing method according to claim 8 .

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