Event estimation system

Abstract

To improve the ability of estimating an event on the basis of an optical signal received from an optical fiber.SOLUTION: The event estimation system includes: a long core material; at least one optical fiber extending in a longer direction of the core material; an optical fiber carrier sensor in which the at least one optical fiber is located in the core material or in a side surface of the core material, the optical fiber carrier sensor being provided in a place which corresponds to a predetermined observation target; and an event estimation device for making an estimation regarding a predetermined event on the basis of an optical signal output from the optical fiber. The core material has a Rockwell hardness of at least 60 measured by the JIS K7202,R scale testing method.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an event inference system. [Background technology]

[0002] A technology is known in which a pattern corresponding to the traveling state of a vehicle on a road is detected based on an optical signal received from an optical communication fiber laid on the road, and the traveling state of a vehicle on the road is detected based on the detected pattern (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 116030 Summary of the Invention [Problem to be solved by the invention]

[0004] When inferring a predetermined event based on an optical signal received from an optical fiber, it is preferable to improve the capability of inferring the event.

[0005] In consideration of the above-mentioned problems, an object of the present invention is to improve the capability of event estimation based on an optical signal received from an optical fiber. [Means for solving the problem]

[0006] (1) One aspect of the present invention that solves the above-mentioned problems is an event estimation system that has a long core material and one or more optical fibers extending in the longitudinal direction of the core material, where the optical fibers are positioned inside or on the circumferential surface of the core material, and is equipped with an optical fiber-carrying sensor provided at a location corresponding to a specified observation target, and an event estimation device that makes an estimation regarding a specified event based on an optical signal output from the optical fiber, wherein the core material has a Rockwell hardness of 60 or more as measured by the JIS K7202, R scale testing method.

[0007] (2) One aspect of the present invention is the event inference system described in (1), in which the optical fiber may form a spiral centered on the axis of the core material.

[0008] (3) One aspect of the present invention is the event inference system described in (1) or (2), in which the optical fiber may be located within a tube wall of a tube serving as the core material.

[0009] (4) One aspect of the present invention is an event inference system according to any one of (1) to (3), in which the optical fiber may be positioned on a circumferential surface of the core material.

[0010] (5) One aspect of the present invention is the event inference system according to any one of (1) to (4), in which the core material may be a cylindrical resin tube.

[0011] (6) One aspect of the present invention is an event inference system according to any one of (1) to (5), in which the core material may be a metal wire. Effect of the Invention

[0012] According to the present invention, it is possible to obtain an effect of improving the ability to estimate an event based on an optical signal received from an optical fiber. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an example of the overall configuration of an event estimation system according to an embodiment of the present invention. [Diagram 2] 1 is a diagram showing an example of the configuration of an optical fiber sensor according to an embodiment of the present invention; [Diagram 3] 10A and 10B are diagrams illustrating another configuration example of the optical fiber sensor according to the present embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of a functional configuration of an event inference device according to the present embodiment. [Diagram 5] 5 is a flowchart showing an example of a processing procedure executed by the event inference device in the present embodiment in response to event inference. [Figure 6] FIG. 1 is a diagram illustrating a specific example of an event inference system according to an embodiment of the present invention. [Figure 7] FIG. 13 is a diagram showing a configuration example of an optical fiber sensor as a modified example of the present embodiment. [Figure 8] FIG. 13 is a diagram showing an example of the configuration of an optical fiber sensor as another modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <Embodiment> FIG. 1 shows an example of the overall configuration of an event inference system according to this embodiment. The event inference system shown in the figure includes an optical fiber sensor 20 and an event inference device 300 .

[0015] The optical fiber-held sensor 20 is disposed in a predetermined manner in the event estimation environment ENV. The event estimation environment ENV is an environment in which an event to be estimated by the event estimation system occurs. The optical fiber-held sensor 20 is a sensor that detects vibrations and sounds generated in response to the event to be estimated as changes in an optical signal. The optical fiber-held sensor 20 disposed in the event estimation environment ENV is connected to the event estimation device 300 via an end of the optical fiber.

[0016] The event estimation device 300 is a device that estimates an event to be estimated by using an optical signal input from the optical fiber sensor 20. In the figure, an example in which the event estimation device 300 is configured as one device is shown, but it may be configured, for example, by multiple devices in which predetermined functions are distributed.

[0017] An example of the configuration of the optical fiber sensor 20 of this embodiment will be described with reference to Fig. 2. The optical fiber sensor 20 shown in the figure has a cylindrical resin tube 21 and an optical fiber 22 extending in the axial (pipe axis) O1 direction of the resin tube 21 within a cylindrical wall 21A of the resin tube 21. In this embodiment, the resin tube 21 is a core material.

[0018] A plurality of optical fibers 22 may be provided inside the tube wall 21A. When bending displacement is detected using the optical fibers 22, at least two are used, and when twisting or flattening displacement is detected, four or more are preferably used. In order to ensure the mechanical strength of the resin tube 21, the number of optical fibers 22 is preferably 20 or less, and more preferably 8 or less. The optical fiber 22 is preferably located within 25% of the thickness of the cylindrical wall 21A from the center bisecting position toward the surface, thereby preventing the optical fiber 22 from being exposed to the outside of the resin tube 21 and being damaged.

[0019] As shown in FIG. 2, the four optical fibers 22 are positioned at 90° intervals around the tube axis 2 in a cross section perpendicular to the axis O1. Moreover, the four optical fibers 22 are arranged in a spiral shape centered on the axis O1. Therefore, in a side view, the optical fibers 22 are inclined at an angle of more than 0 degrees and less than 90 degrees with respect to the axis O1 in the circumferential direction of the resin tube 21. The spiral pitch P of the optical fibers 22 is preferably 50 mm or more and 2000 mm or less, more preferably 100 mm or more and 500 mm or less, and even more preferably 300 mm or more and 400 mm or less. If the spiral pitch P is equal to or more than the upper limit, the measurement accuracy can be improved without excessively increasing the length of the optical fibers 22. If the spiral pitch P is equal to or less than the upper limit, the measurement accuracy can be further improved.

[0020] The optical fiber sensor 20 of this embodiment has a folded portion 222 and a folded portion 223 protruding from one end edge of the resin tube 21 in the longitudinal direction (the direction of the axis O1). The folded portion 222 is a member in which the optical fiber 22a and the optical fiber 22b protruding from one end edge in the longitudinal direction of the resin tube 21 are connected to each other outside the resin tube 21 (in the direction of the axis O1 away from the resin tube 21). The optical fiber 22a and the optical fiber 22b are adjacent to each other in the circumferential direction of the resin tube 21. The folded portion 223 is a member in which the optical fiber 22c and the optical fiber 22d protruding from one end edge of the resin tube 21 are connected outside the resin tube 21. The optical fiber 22c and the optical fiber 22d are adjacent to each other in the circumferential direction of the resin tube 21. That is, in this embodiment, the optical fiber 22 protrudes from the resin tube 21 at one end in the direction of the axis O1, and has folded-back portions 222, 223 outside the resin tube 21, in which an arbitrary optical fiber 22 is connected to an arbitrary other optical fiber 22 adjacent to the arbitrary optical fiber 22 in the circumferential direction of the resin tube 21, which is the core material.

[0021] The optical fiber sensor 20 has a folded portion 229 protruding from the other end edge of the resin tube 21 in the longitudinal direction. The folded-back portion 229 is a member in which the optical fibers 22g and 22h protruding from the other longitudinal edge of the resin wall portion 24 are connected to the outside of the resin tube 21 (in the direction away from the resin tube 21 in the direction of the axis O1). The optical fibers 22g and 22h are adjacent to each other in the circumferential direction of the resin tube 21. The optical fibers 22g and 22h protrude from the other longitudinal edge of the resin tube 21. The optical fiber end 22e and the optical fiber end 22f do not form a folded-back portion. The optical fiber end 22e is connected to the event estimation device 300.

[0022] In this embodiment, one optical fiber is folded back to form folded-back portions 222, 223, and 229, and optical fiber ends 22e and 22f are protruded from the other edge. Thus, four optical fibers 22 are positioned within the resin tube 21.

[0023] The thickness of the tube wall 21A is preferably 2.5 mm or more and 10 mm or less, and more preferably 3 mm or more and 5 mm or less. When the thickness of the tube wall 21A is equal to or more than the lower limit, the rigidity of the optical fiber-supported resin tube can be further increased. When the thickness of the tube wall 21A is equal to or less than the upper limit, excessive weight can be prevented.

[0024] The outer diameter R of the cylindrical wall 11A is preferably 20 mm or more and 50 mm or less, and more preferably 30 mm or more and 40 mm or less. When the outer diameter R is equal to or more than the lower limit, interference between the optical fibers 22 can be more effectively suppressed. When the outer diameter R is equal to or less than the upper limit, displacement can be more appropriately followed.

[0025] The cylindrical wall 21A may be made of, for example, a resin composition containing the resin (A), ceramics, or the like. Examples of the resin (A) include polyolefin resins, polyvinyl chloride resins, acrylamide-butadiene-styrene resins (ABS), polyamide resins, and silicone resins. Examples of polyolefin resins include polyethylene, polypropylene, polybutene, ethylene-vinyl acetate copolymer, and ethylene-α-olefin copolymer. Examples of vinyl chloride resins include chlorinated vinyl chloride and propylene-vinyl chloride copolymers. An example of the polyamide resin is so-called nylon 66. These resins (A) may be used alone or in combination of two or more.

[0026] The optical fiber 22 has a core, a cladding, and a coating layer, and generates scattered light such as Brillouin scattering and Raman scattering due to distortion of the core, temperature, etc., by irradiating discontinuous pump light such as laser light into the core. For example, an optical fiber composed of a core and a cladding can be suitably used as this type of optical fiber 22. Examples of materials for the core and cladding include plastic and quartz glass.

[0027] Examples of optical fibers include an optical fiber strand having a primary coating around the cladding, an optical fiber core having a secondary coating around the primary coating, and an optical fiber cord having a reinforcing material around the secondary coating and an outer jacket covering the reinforcing material.

[0028] Examples of materials for the primary coating include ultraviolet curing resin, polyamide, fluororesin, polyimide, and polyethylene. Examples of materials for the secondary coating include flame-retardant polyester elastomers and polyimides. Examples of the reinforcing material include glass fiber, carbon fiber, and aramid fiber. Examples of materials for the outer cover include flame-retardant polyolefins such as flame-retardant polyethylene, flame-retardant cross-linked polyolefins such as flame-retardant cross-linked polyethylene, and heat-resistant vinyl.

[0029] The type of optical fiber 22 is not particularly limited, and can be selected according to the detection target such as strain, vibration, or sound, the detection method, the type of scattered light used during detection, etc. For example, at least one type of optical fiber selected from the group consisting of a single-mode optical fiber, a multimode optical fiber, and a polarization-maintaining optical fiber can be used.

[0030] When a plurality of optical fibers 22 are arranged in the optical fiber sensor 20, the plurality of optical fibers 22 may be the same type of optical fiber or different types of optical fibers.

[0031] When detecting vibrations or sounds according to this embodiment, Brillouin scattered light, Rayleigh scattered light, or the like can be preferably used as the scattered light, and a single-mode optical fiber is preferably used since a sharp peak can be obtained. Also, Raman scattered light or the like can be used as the scattered light, and a multimode optical fiber can be used.

[0032] The outer diameter of the optical fiber 22 is preferably 125 to 2000 μm, and more preferably 150 to 1000 μm. When the outer diameter of the optical fiber 22 is equal to or more than the above lower limit, the strength can be further increased.

[0033] It is preferable that the optical fiber sensor 20 is rigid. If the optical fiber sensor 20 is rigid, the displacement applied to the optical fiber sensor 20 can be detected more accurately and in detail.

[0034] The rigidity of the resin pipe 21 can be indicated by the Rockwell hardness measured according to the JIS K7202, R scale test method. The Rockwell hardness of the resin pipe 21 is preferably 60 or more, more preferably 70 or more, and even more preferably 75 or more. When the Rockwell hardness of the resin pipe 21 is equal to or more than the upper limit, the optical fiber sensor 20 becomes more rigid, and the accuracy of detecting the displacement can be further improved. The upper limit of the Rockwell hardness of the resin pipe 21 is substantially 130 or less. The Rockwell hardness of the resin pipe 21 is a value measured by the R-scale test method of JIS K7202 (2001).

[0035] A method for manufacturing the optical fiber sensor of this embodiment will be described. A polyolefin resin composition containing only the above resin (A) and an optical fiber 22 are supplied to a mold, and an extrusion molded body in which the resin tube and the optical fiber 22 are integrally molded is taken up by a take-up machine installed downstream of the mold, thereby obtaining the optical fiber-supported sensor 20 shown in Figure 2.

[0036] 2, the optical fiber is located inside the cylindrical wall of a cylindrical resin tube. However, the present invention is not limited to this, and the optical fiber may be located outside the cylindrical wall (i.e., on the outer circumferential surface of the resin tube). In the above-described embodiment, the core material is a cylindrical resin tube, but the present invention is not limited to this. The core material does not have to be cylindrical (i.e., hollow) and may be solid. When the core material is solid, the optical fiber may be located within the core material or may be located around the periphery of the core material.

[0037] A configuration example of the optical fiber sensor 20A in which the core material is solid and the optical fiber is located on the outer periphery of the core material will be described with reference to Fig. 3. The optical fiber sensor 20A can be used in place of the optical fiber sensor 20 in the event inference system of this embodiment. Alternatively, when the event inference system of this embodiment is provided with a plurality of optical fiber sensors, the optical fiber sensor 20 and the optical fiber sensor 20A may be mixed in the plurality of optical fiber sensors. 3, the same parts as those in FIG. 2 are given the same reference numerals and their explanations are omitted, and the following mainly describes the differences from the optical fiber sensor 20 in FIG.

[0038] The optical fiber sensor 20A has a long rod-shaped core material 121 and an optical fiber 22 located on the outer circumferential surface of the core material 121. The optical fiber 22 draws a spiral around the axis O2. The spiral pitch P2 of the spiral drawn by the optical fiber 22 is the same as the spiral pitch P.

[0039] The core material 121 is a straight rod-like solid member. By making the core material 121 a solid member, the rigidity of the optical fiber sensor 20A can be further increased, and the detection accuracy of the displacement can be further improved. The outer diameter R2 of the core material 121 is the same as the outer diameter R of the resin pipe 21. Examples of materials for the core 121 include a resin composition containing the resin (B), ceramics, metal, glass, and the like. Resin (B) is the same as resin (A). Examples of metals include stainless steel, aluminum, iron, copper, titanium, magnesium, and alloys containing these.

[0040] The optical fiber 22 is fixed in close contact with the outer circumferential surface of the core material 121. Methods for fixing the optical fiber 22 to the outer circumferential surface of the core material 121 include, for example, adhesion, fusion, and tape attachment.

[0041] The Rockwell hardness of the core material 121 is similar to that of the resin pipe 21 .

[0042] The optical fiber sensor 20A may be manufactured, for example, by winding the optical fiber 22 around a core material 121 and bonding it with an adhesive.

[0043] An example of the configuration of an event inference device 300 according to this embodiment will be described with reference to FIG. In the following description, an example will be given in which the event estimation device 300 is connected to one optical fiber sensor 20. Also, an example will be given in which one optical fiber sensor 20 has four optical fibers 22 each individually arranged in a spiral shape.

[0044] The event inference device 300 in the figure includes a detection unit 301, an inference unit 302, and a storage unit 303. The functions of the event inference device 300 in the figure may be realized by executing a CPU (Central Processing Unit) program included in the event inference device 300 as hardware.

[0045] The detection unit 301 detects a predetermined detection item used for event estimation by utilizing an optical signal received from the optical fiber 22. The detection unit 301 in the figure is connected to optical fiber ends 22e (22e-1, 22e-2, 22e-3, 22e-4) of each of the four optical fibers 22. In other words, the detection unit 301 is connected to each of the four optical fibers 22 provided in one optical fiber-held sensor 20.

[0046] The detection unit 301 inputs pulsed light from the optical fiber end 22e to each of the four connected optical fibers 22. In the optical fiber 22, scattered light generated as the input pulsed light is transmitted returns to the input side as return light via the same optical fiber 22. The detection unit 301 receives the return light as an optical signal.

[0047] For example, in the event estimation environment ENV, vibrations and sounds occur in response to the occurrence of an event to be estimated. The occurrence of such vibrations and sounds affects the scattered light transmitted in the optical fiber 22 via the ground or air, and also affects the return light received by the detection unit 301. In other words, the return light changes in response to the vibrations and sounds occurring in the event estimation environment ENV.

[0048] The detection unit 301 detects vibrations or sounds occurring in the event estimation environment ENV based on a change in the received return light. Specifically, the detection unit 301 may detect an amplitude pattern, a frequency pattern, or the like of the vibrations or sounds.

[0049] The detection unit 301 may perform the above-mentioned vibration and sound detection individually for each of the four optical signals received from the four optical fibers 22. In this case, the detection unit 301 is configured to obtain four detection results corresponding to the same detection target. The detection unit 301 outputs the obtained four detection results DT (DT-1, DT-2, DT-3, DT-4) to the estimation unit 302. The detection unit 301 may store the detection result DT in the storage unit 303 .

[0050] The estimation unit 302 estimates the event to be estimated based on the detection result DT. The estimation unit 302 in the figure may estimate the event to be estimated using the four detection results DT. In this case, the estimation unit 302 may estimate the event using a result (integrated detection result) of integrating the four detection results DT (DT-1, DT-2, DT-3, DT-4). Alternatively, the estimation unit 302 may estimate the event using one or more detection results DT determined to be highly reliable among the four detection results DT (DT-1, DT-2, DT-3, DT-4).

[0051] The estimation unit 302 may use a trained model for estimating an event. Such a trained model is constructed, for example, by making a learning device execute learning using teacher data in which detection results are associated with events that occur corresponding to the detection results.

[0052] The estimation unit 302 may store an estimation result for the event (event estimation result) in the storage unit 303. In addition, the estimation unit 302 may output the event estimation result, for example, to an external display or printer. In addition, data in which the event estimation result obtained by the estimation unit 302 is associated with the corresponding detection result DT may be used as teacher data for constructing a trained model of the estimation unit 302.

[0053] An example of a process procedure executed by the event estimation device 300 in response to event estimation will be described with reference to the flowchart of FIG. Step S100 : In the event estimation device 300 , the detection unit 301 receives optical signals from each of the optical fibers 22 .

[0054] Step S102: The detection unit 301 detects a detection item such as vibration or sound by using the optical signal received in step S100. The detection unit 301 outputs the detection result DT obtained by detecting the detection item to the estimation unit 302.

[0055] Step S104 : The estimation unit 302 acquires the detection result output by the detection unit 301 .

[0056] Step S106: The estimation unit 302 performs estimation regarding the event to be estimated by using the detection result acquired in step S104. The estimation unit 302 may store the estimation result in the storage unit 303 as described above, or may output the estimation result to the outside.

[0057] In the event inference system of this embodiment configured as described above, an event is inferred based on an optical signal from the optical fiber 22 arranged in the longitudinal direction of a core material such as a resin pipe 21. A core material such as the resin pipe 21 has a certain rigidity, so that external energy such as vibration and sound can be transmitted to the optical fiber 22 with low loss. As a result, the detection accuracy of the detection items in the event inference device 300 is improved, and the accuracy of event inference is also improved. In other words, the configuration of this embodiment improves the ability of event inference.

[0058] In addition, in this embodiment, the optical fiber 22 is provided in a spiral shape with the axis O1 as the center for the optical fiber sensor 20. The optical fiber 22 may be provided linearly along the axis O1 in the tube wall 21A, for example. However, by providing the optical fiber 22 in a spiral shape as in this embodiment, the length of the optical fiber present per unit length of the resin tube 21 can be increased compared to when the optical fiber 22 is provided linearly. This makes it possible to increase the spatial resolution in measurement, thereby improving the detection accuracy by the detection unit 301 and the estimation accuracy by the estimation unit 302.

[0059] Moreover, since the optical fiber 22 is provided in a spiral shape, the optical fiber 22 is arranged around the circular cylindrical wall 21A, so that it is possible to perform sensing with equal sensitivity for vibrations, sounds, and the like coming from all directions (360° directions) around the axis O1, causing changes in the return light. This makes it possible to obtain a large amount of information about the detection items detected by the detection unit 301, and to obtain good event estimation results.

[0060] Furthermore, the trained model used by the estimation unit 302 for event estimation can be constructed using teacher data that associates the patterns of the detection results output by the detection unit 301 with events that occur corresponding to the patterns of the detection results. In this case, the estimation accuracy can be improved by using the patterns of the detection results in the teacher data that are detected by the detection unit 301 using the optical signal obtained by the optical fiber-held sensor 20 of this embodiment in which the optical fiber 22 is provided in a spiral shape.

[0061] Furthermore, by improving estimation accuracy as described above and enabling sensing in all directions, it becomes possible to relax or eliminate restrictions on what can be detected and what events can be estimated, thereby improving event estimation capabilities in this respect as well.

[0062] A specific example of the event inference system of this embodiment will be described with reference to Fig. 6. In Fig. 6, the same parts as those in Fig. 1 are given the same reference numerals and the description thereof will be omitted. In the event inference system shown in the figure, an optical fiber sensor 20 is buried under a road RD along which a vehicle CR such as an automobile passes. The optical fiber 22 in the optical fiber sensor 20 thus installed changes the return light in response to vibrations and sounds generated by the vehicle CR passing over the road RD. In the event estimation device 300, the detection unit 301 uses the received return light to detect vibrations and sounds generated in response to a vehicle passing over the road RD, and outputs the obtained detection result DT to the estimation unit 302. The estimation unit 302 estimates the passing status of the vehicle CR on the road RD based on the input detection result DT. Specifically, the estimation unit 302 may estimate the speed of each vehicle CR passing the road RD, the type of each vehicle CR passing the road RD (e.g., types such as passenger cars, freight cars, motorcycles, etc.), the weight and size of each vehicle CR passing the road RD, the unevenness of the road RD, the falling status of objects such as luggage onto the road RD, etc. Furthermore, information on the result of estimation by the estimation unit 302 may be stored in the storage unit 303. Furthermore, information on the result of estimation by the estimation unit 302 may be output to an external computer device, a printer, or the like.

[0063] <Modification> Modifications of the optical fiber sensor of this embodiment will be described below. The optical fiber sensor shown as a modification can be disposed in the event recognition environment ENV in place of the optical fiber sensor 20 in FIG.

[0064] 7 shows a configuration example of an optical fiber sensor 30 as a modified example of this embodiment. The figure shows a cross section of the optical fiber sensor 30 cut along a direction perpendicular to the extension direction. The optical fiber sensor 30 in the figure includes one optical fiber 22. The optical fiber 22 is covered with a solid inner coating 31. The inner coating 31 is further covered with a solid outer coating 32. The inner coating 31 and the outer coating 32 may be formed of, for example, a resin. In the configuration shown in the figure, a portion corresponding to the core material (resin tube 21) of the optical fiber sensor 20 in Fig. 2 may be an inner coating 31 or an outer coating 32. The hardness of the inner coating 31 or the outer coating 32 serving as the core material in this embodiment may be equivalent to that of the core material (resin tube 21) of the optical fiber sensor 20, for example.

[0065] When a structure has one optical fiber 22, such as the optical fiber-carrying sensor 30 in the same figure, the detection unit 301 in the event estimation device 300 may be configured to obtain one detection result DT from one optical signal output from the one optical fiber 22, and the estimation unit 302 may be configured to estimate the event using one detection result DT.

[0066] FIG. 8 shows a configuration example of an optical fiber sensor 30A as another modified example of this embodiment. The optical fiber-carrying sensor 30A includes two optical fibers 22-1 and 22-2. For example, the optical fiber 22-1 may be used for detection (measurement), and the optical fiber 22-2 may be used for temperature compensation. The optical fiber 22-1 is covered with a solid inner coating 31-1, and the optical fiber 22-2 is covered with a solid inner coating 31-2. The inner coating 31-1 and the inner coating 31-2 are in contact with each other and are covered with a solid outer coating 32. An outer diameter R3 of the solid outer coating 32 is preferably 5 mm or more and 20 mm or less.

[0067] In the case of the optical fiber-supported sensor 30A of this modified example, the detection unit 301 may be configured to obtain one detection result DT using the optical signal output from the optical fiber 22-1 while performing temperature compensation using the optical signal output from the optical fiber 22-2, and the estimation unit 302 may be configured to estimate an event using one detection result DT.

[0068] In the event estimation system of this embodiment, the items (detection items) that the detection unit 301 detects are not limited to vibration and sound. For example, the detection unit 301 may be configured to detect temperature, distortion, dynamic pressure, etc. Based on the detection results of such detection items, the estimation unit 302 may estimate a predetermined event that has a correlation with temperature, distortion, dynamic pressure, displacement, vibration frequency, vibration acceleration, etc.

[0069] The detection unit 301 may divide the optical signals of the optical fibers 22 provided in one optical fiber sensor 20 into a plurality of groups and detect different detection items for each group. As a specific example, the detection unit 301 may detect vibrations using optical signals from two optical fibers 22 divided into a predetermined group among the four optical fibers 22, and detect sound using optical signals from the remaining two optical fibers 22 divided into another group. In addition, in response to the detection unit 301 detecting a plurality of different detection items, the estimation unit 302 may estimate a plurality of different events by selecting and using a predetermined detection item from the plurality of detection items.

[0070] A plurality of optical fiber sensors 20 may be connected to the event estimation device 300. In this case, the event estimation device 300 may estimate the same event by using optical signals received from the optical fibers 22 arranged in the plurality of optical fiber sensors 20. Alternatively, the plurality of optical fiber sensors 20 connected to the event estimation device 300 may be divided into a plurality of groups, and the event estimation device 300 may estimate different events corresponding to each group.

[0071] In addition, a program for realizing the function of the above-mentioned event inference device 300 may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed to perform the processing of the above-mentioned event inference device 300. Here, "reading a program recorded in a recording medium into a computer system and executing it" includes installing the program into a computer system. The "computer system" here includes hardware such as an OS and peripheral devices. The "computer system" may also include a plurality of computer devices connected via a network including the Internet, a WAN, a LAN, a dedicated line, and other communication lines. The "computer-readable recording medium" refers to portable media such as a flexible disk, an optical magnetic disk, a ROM, a CD-ROM, and a storage device such as a HDD or SDD built into a computer system. In this way, the recording medium storing the program may be a non-transient recording medium such as a CD-ROM. The recording medium also includes a recording medium provided inside or outside the computer system that can be accessed from a distribution server in order to distribute the program. The code of the program stored in the recording medium of the distribution server may be different from the code of the program in a format executable by a terminal device. That is, as long as it can be downloaded from a distribution server and installed in a form executable by a terminal device, the format in which it is stored in the distribution server does not matter. The program may be divided into multiple parts, downloaded at different times, and then combined on the terminal device, or each of the divided programs may be distributed by a different distribution server. Furthermore, the "computer-readable recording medium" includes a program that holds a program for a certain period of time, such as a volatile memory (RAM) inside a computer system that becomes a server or a client when a program is transmitted via a network. The program may also be a program for realizing part of the above-mentioned functions. Furthermore, the program may be a so-called difference file (difference program) that can realize the above-mentioned functions in combination with a program already recorded in the computer system. [Explanation of symbols]

[0072] 20, 20A, 30, 30A Optical fiber carrying sensor, 21 Resin tube, 22, 22-1, 22-2 Optical fiber, 31, 31-1, 31-2 Inner coating, 32 Outer coating, 22e (22e-1, 22e-2, 22e-3, 22e-4) Optical fiber end, 121 Core material, 300 Event estimation device, 301 Detection unit, 302 Estimation unit, 303 Memory unit

Claims

1. A long core material, and one or more optical fibers extending in the longitudinal direction of the core material; an optical fiber sensor provided at a location corresponding to a predetermined observation target, the optical fiber being positioned inside or on a peripheral surface of the core material; an event estimation device that performs an estimation regarding a predetermined event based on the optical signal output from the optical fiber; The core material has a Rockwell hardness of 60 or more as measured by the JIS K7202, R scale test method. Event inference system.

2. The optical fiber forms a spiral around the axis of the core material. The event inference system according to claim 1 .

3. The optical fiber is disposed within the cylindrical wall of the core tube. The event inference system according to claim 1 or 2.

4. The optical fiber is disposed on the circumferential surface of the core material. The event inference system according to claim 1 or 2.

5. The core material is a cylindrical resin tube. The event inference system according to claim 1 or 2.

6. The core material is a metal wire. The event inference system according to claim 1 or 2.

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