Event identification device, event identification method and program

Abstract

To provide an event identification device that have improved ability to identify an event based on an optical signal received from an optical fiber.SOLUTION: An event identification device comprises: an information generation unit capable of generating, as event identification information for use in event identification, at least time series vibration information indicating a change in vibration over time for each specific position, time series vibration position information indicating a change in a vibration position over time, and frequency feature information indicating frequency characteristics of vibration in a unit time for each specific position, on the basis of an optical signal output from an optical fiber provided in a given environment; and an event identification unit which identifies a prescribed event using two or more pieces of identification use information generated by the information generation unit.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an event identification device, an event identification method, and a program. [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] In identifying a predetermined event based on an optical signal received from an optical fiber, it is preferable to improve the ability to identify the event.

[0005] SUMMARY OF THE PRESENT EMBODIMENT In consideration of the above-mentioned problems, an object of the present invention is to improve the ability to identify events 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 identification device that includes an information generation unit that is capable of generating, as event identification information to be used for event identification based on an optical signal output from an optical fiber arranged in a specified environment, at least time-series vibration information indicating a change in vibration over time for each specific position, time-series vibration position information indicating a change in vibration position over time, and frequency characteristic information indicating the frequency characteristics of vibration in unit time for each specific position, and an event identification unit that performs identification regarding a specified event by using two or more pieces of identification utilization information generated by the information generation unit.

[0007] (2) One aspect of the present invention is the event identification device described in (1), wherein the event identification unit may include a plurality of primary classifiers, each of which outputs a primary identification result in response to an input of any one of the plurality of pieces of identification-use information, and a secondary classifier that outputs a final identification result in response to an input of the primary identification results output by each of the primary classifiers.

[0008] (3) One aspect of the present invention is the event identification device described in (1), wherein the event identification unit may include a single identifier that outputs a final identification result in response to input of all of the identification use information.

[0009] (4) One aspect of the present invention is the event identification device described in (1), wherein the event identification unit may include a predetermined number of primary classifiers that output a primary identification result in response to input of a portion of a plurality of event-utilization identification information, and a secondary classifier that outputs a final identification result in response to input of the primary identification result and the event-utilization identification information that is not input to the primary classifiers.

[0010] (5) One aspect of the present invention is an event identification method including an information generation step capable of generating, based on an optical signal output from an optical fiber arranged in a predetermined environment, event identification information to be used for event identification, including at least time-series vibration information indicating a change in vibration over time for each specific position, time-series vibration position information indicating a change in vibration position over time, and frequency characteristic information indicating the frequency characteristics of vibration in unit time for each specific position, and an event identification step of identifying a predetermined event using two or more pieces of identification utilization information generated by the information generation step.

[0011] (6) One aspect of the present invention is a program for causing a computer to function as an information generation unit capable of generating, as event identification information to be used for event identification based on an optical signal output from an optical fiber arranged in a specified environment, at least time-series vibration information indicating a change in vibration over time for each specific position, time-series vibration position information indicating a change in vibration position over time, and frequency characteristic information indicating the frequency characteristics of vibration in unit time for each specific position, and an event identification unit that uses two or more pieces of identification utilization information generated by the information generation unit to identify a specified event. Effect of the Invention

[0012] According to the present invention, it is possible to obtain an effect of improving the ability to identify events based on optical signals received from optical fibers. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram illustrating an example of the overall functional configuration of an event identification 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 identification device according to the present embodiment. [Diagram 5]10 is a diagram showing an example of identification and utilization information generated by an information generating unit in the present embodiment. FIG. [Figure 6] 2 is a diagram illustrating a first example of the configuration of an event identification unit in the present embodiment. FIG. [Figure 7] FIG. 13 is a diagram illustrating a second example of the configuration of the event identification unit in this embodiment. [Figure 8] FIG. 13 is a diagram illustrating a third example of the configuration of the event identification unit in this embodiment. [Figure 9] 1 is a diagram showing a specific application example of the event identification system according to the present embodiment; [Figure 10] FIG. 13 is a diagram showing a configuration example of an optical fiber sensor as a modified example of the present embodiment. [Figure 11] 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> [Overall configuration example of an event identification system] 1 shows an example of the overall configuration of an event discrimination system according to the present embodiment. The event discrimination system in the figure includes an optical fiber 22 and an event discrimination device 300.

[0015] In this embodiment, the optical fiber 22 is disposed in a predetermined manner in the event recognition environment ENV. Specifically, the optical fiber 22 is included in the structure of the optical fiber sensor 20, and the optical fiber sensor 20 is disposed in the event recognition environment ENV. The event recognition environment ENV is an environment in which events that are to be recognized by the event recognition system occur.

[0016] In this embodiment, the optical fiber sensor 20 is a sensor that detects vibrations and sounds generated in response to an event to be identified as a change in an optical signal. The optical fiber sensor 20 disposed in the event identification environment ENV is connected to the event identification device 300 via the end of the optical fiber 22.

[0017] The event identification device 300 is a device that identifies an event to be identified by utilizing an optical signal input from the optical fiber sensor 20. In the figure, an example in which the event identification device 300 is configured as one device is shown, but it may also be configured, for example, by multiple devices in which predetermined functions are distributed.

[0018] [Example of optical fiber sensor configuration] 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.

[0019] There may be a plurality of optical fibers 22 located inside the cylindrical wall 21A. In the figure, an example in which four optical fibers 22 are provided is shown. Fig. 2 shows an example in which four optical fibers 22 are positioned at 90° intervals around the tube axis 2 in a cross section perpendicular to the axis O1. Fig. 2 also shows an example in which the four optical fibers 22 are arranged in a spiral shape centered on the axis O1. The spiral pitch P of the optical fibers 22 may be set according to the required measurement accuracy, etc.

[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 end 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 end 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 identification 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 optical fiber 22 may have a core, a clad, and a coating layer, and may generate scattered light such as Brillouin scattering or Raman scattering due to distortion or temperature of the core when discontinuous pump light such as laser light is incident on the core. For example, an optical fiber composed of a core and a clad may be suitably used as the optical fiber 22. Examples of materials for the core and the clad include plastic and quartz glass.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] With reference to Fig. 3, 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. The optical fiber sensor 20A can be used in place of the optical fiber sensor 20 in the event identification system of this embodiment. Alternatively, when multiple optical fiber sensors are provided in the event identification system of this embodiment, the optical fiber sensor 20 and the optical fiber sensor 20A may be mixed in the multiple 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.

[0029] 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.

[0030] 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 the material of the core material 121 include a resin composition, ceramic, metal, glass, and the like.

[0031] 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.

[0032] In the optical fiber sensor 20A, the optical fiber 22 may be fixed to the core material 121 by, for example, winding the optical fiber 22 around the core material 121 and bonding it with an adhesive.

[0033] [Example of functional configuration of event identification device] An example of the functional configuration of the event identification device 300 of this embodiment will be described with reference to FIG. In the following description, an example will be given in which the event identification 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.

[0034] The event identification device 300 in the figure includes a receiving unit 301, an information generating unit 302, an event identification unit 303, and a storage unit 304. The functions of the event identification device 300 in the figure may be realized by executing a program using a CPU (Central Processing Unit) included in the event identification device 300 as hardware.

[0035] The receiving unit 301 receives an optical signal from the optical fiber 22. In this case, the receiving unit 301 is connected to the optical fiber ends 22e (22e-1, 22e-2, 22e-3, 22e-4) of the four optical fibers 22. That is, the receiving unit 301 is connected to each of the four optical fibers 22 provided in one optical fiber-carrying sensor 20.

[0036] The receiving unit 301 inputs pulsed light from the optical fiber end 22e into each of the four connected optical fibers 22. In the optical fiber 22, scattered light is generated as the input pulsed light is transmitted, and returns to the input side as return light via the same optical fiber 22. The receiving unit 301 receives the return light as an optical signal.

[0037] For example, in the event recognition environment ENV, vibrations and sounds occur in response to the occurrence of an event to be recognized. 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 receiving unit 301. In other words, the return light changes in response to the vibrations and sounds generated in the event recognition environment ENV.

[0038] The optical signal Sopt received by the receiving unit is input to the information generating unit 302. The information generating unit 302 generates a plurality of pieces of identification information using the input optical signal Sopt. The identification information is information used by the event identifying unit 303 to identify a target event (event identification).

[0039] The event identification unit 303 executes event identification using the multiple event identification information generated by the information generation unit 302, and outputs the identification result (event identification result). For example, the event identification unit 303 may store the event identification result in the storage unit 304. The event identification unit 303 may also output the event identification result by an external display or printer. Furthermore, data in which the event identification result obtained by the event identification unit 303 is associated with the corresponding identification utilization information may be used as teacher data for constructing a trained model used by the event identification unit 303.

[0040] The memory unit 304 stores various information related to the event identifier 300 .

[0041] [Generation of Identification and Use Information by the Information Generation Unit] Generation of identification-use information by the information generating unit 302 of this embodiment will be described with reference to FIG. An optical signal Sopt received by the receiving unit 301 is input to the information generating unit 302. In Fig. 4, the receiving unit 301 receives four optical signals. For ease of explanation, a case will be taken as an example in which the receiving unit 301 inputs one optical signal Sopt obtained by combining the four received optical signals to the information generating unit 302.

[0042] The information generating unit 302 generates three pieces of identification and use information based on the input optical signal Sopt. That is, as shown in Fig. 5, the information generating unit 302 is capable of generating time-series waveform information D1, time-series vibration position information D2, and time-series frequency characteristic information D3 as the identification and use information.

[0043] The time-series waveform information D1 is information (an example of time-series vibration information) indicating a change over time of a waveform corresponding to a vibration occurring at a specific position in the event identification environment ENV. The information generating unit 302 may generate a plurality of pieces of time-series waveform information D1 corresponding to each of a plurality of specific positions defined in the event identification environment ENV.

[0044] The time-series vibration position information D2 is information indicating a position change according to the passage of time of a vibration generated in the event identification environment ENV. The time-series waveform information D1 may generate a plurality of time-series vibration position information D2 according to each generated vibration.

[0045] The time-series frequency characteristic information D3 is information indicating a change over time of a frequency characteristic corresponding to a vibration occurring at a specific position in the event identification environment ENV. The information generating unit 302 may generate a plurality of pieces of time-series frequency characteristic information D3 corresponding to each of a plurality of specific positions defined in the event identification environment ENV. The time-series frequency characteristic information D3 may be a spectrogram.

[0046] The optical signal Sopt input to the information generating unit 302 is a signal that changes in response to the distortion of the optical fiber 22 caused by vibrations occurring in the event identification environment ENV. That is, the optical signal Sopt is information indicating the distortion of the optical fiber 22. Therefore, the information generating unit 302 performs a predetermined calculation on the input optical signal Sopt to convert it into vibration velocity information indicating the vibration velocity. The information generating unit 302 performs differentiation (first-order differentiation) on the vibration velocity information to convert it into vibration acceleration information indicating the acceleration of the vibration (vibration acceleration).

[0047] The information generating unit 302 detects vibration waveforms that occur at each time corresponding to each specific position from the vibration acceleration indicated by the vibration acceleration information obtained as described above, and generates time-series waveform information D1 that indicates vibrations corresponding to the passage of time at each specific position. Furthermore, the information generating unit 302 generates time-series vibration position information D2 by detecting a position that changes with time for a specific vibration from the vibration acceleration indicated by the vibration acceleration information. Furthermore, the information generating unit 302 performs a process of detecting frequency characteristics corresponding to a unit time by performing frequency analysis (e.g., FFT) on a time window set for the vibration acceleration indicated by the vibration acceleration information, while shifting the time window, and generates time-series frequency characteristic information D3 by arranging the frequency characteristics obtained corresponding to each time window over time.

[0048] [Event Identification Unit Configuration Example: Example 1] Below, three examples of the configuration of the event identification section 303 of this embodiment will be described, and the first example will be described first. 6 shows a first example of the configuration of the event discriminator 303. The event discriminator 303 in the figure includes one discriminator 331. The identifier 331 receives the time-series waveform information D1, the time-series vibration position information D2, and the time-series frequency characteristic information D3 generated by the information generating unit 302 (not shown in the figure). The discriminator 331 executes event discrimination in response to inputs of time-series waveform information D1, time-series vibration position information D2, and time-series frequency characteristic information D3, and outputs a final discrimination result D10.

[0049] The classifier 331 may be configured to output the final classification result D10 using artificial intelligence. In this case, the learning model used by the classifier 331 may be constructed by, for example, having the learner execute learning using learning data in which the data sets of the time-series waveform information D1, the time-series vibration position information D2, and the time-series frequency characteristic information D3 are associated with the classification result (final classification result). Note that the learning model used by the classifier 331 may be constructed by, for example, deep learning.

[0050] In this manner, in this embodiment, a predetermined event is identified using a plurality of pieces of identification-use information. The identification-use information has different elements, such as events and various conditions that increase the identification accuracy. In other words, each piece of identification-use information has different advantages. For this reason, for example, event identification using a single piece of identification-use information may not provide sufficient accuracy in the identification result. Therefore, by performing event identification using multiple pieces of identification-use information as in this embodiment, it is possible to compensate for elements for which the identification accuracy is low using a certain piece of identification-use information by using the superiority of other identification-use information, and the accuracy of the final identification result D10 can be improved.

[0051] In addition, in this example, a plurality of pieces of identification-use information are input to one identifier 331, which outputs a final identification result D10. In this configuration, since there is only one identifier 331, the processing load is reduced, and high-speed processing can be expected.

[0052] In this example, the event identification unit 303 may be configured to output the final identification result D10 in response to input of a plurality of (two in this case) pieces of the time-series waveform information D1, the time-series vibration position information D2, and the time-series frequency characteristic information D3. In this case, when the identification-use information input to the identifier 331 is fixed, the information generating unit 302 may be configured to generate the identification-use information to be input to the identifier 331 from among the identification-use information that can be generated, and not to generate the identification-use information that is not input to the identifier 331. In addition, some of the identification use information to be input to the identifier 331 may be changed in response to changes in the event to be identified, changes in various conditions in the event identification environment ENV, and the like.

[0053] [Example of the configuration of the event identification unit: Example 2] 7 shows a second example of the configuration of the event discrimination unit 303. The event discrimination unit 303 in the figure includes three primary discriminators 332 (332-1, 332-2, 332-3) corresponding to the time-series waveform information D1, the time-series vibration position information D2, and the time-series frequency characteristic information D3, respectively. The event discrimination unit 303 also includes one secondary discriminator 333.

[0054] The primary classifier 332-1 receives time-series waveform information D1 as input, and outputs a primary classification result according to the input time-series waveform information D1. The primary classifier 332-2 receives the time-series vibration position information D2 as input, and outputs a primary classification result according to the input of the time-series vibration position information D2. The primary classifier 332-3 receives time-series frequency characteristic information D3 as input, and outputs a primary classification result according to the input time-series frequency characteristic information D3. That is, in the second example event identification section 303, as a first stage of event identification, three primary identification results are obtained corresponding to the individual identification utilization information of the time series waveform information D1, the time series vibration position information D2, and the time series frequency characteristic information D3.

[0055] The primary classification results from the primary classifiers 332-1, 332-2, and 332-3 are input to the secondary classifier 333. The secondary classifier 333 outputs a classification result (final classification result) based on the three input primary classification results.

[0056] In this example, each piece of identification-use information is input to a corresponding primary classifier 332 to obtain a primary classification result corresponding to each piece of identification-use information. In this case, each primary classifier 332 can be configured to be adapted to the corresponding identification-use information, so that the accuracy of the primary classification result corresponding to each piece of identification-use information can be improved. In addition, in the configuration of this example, it is also easy to weight the primary classification result of each primary classifier 332 corresponding to each piece of identification-use information by, for example, giving a coefficient. Then, the secondary classifier 333 integrates such primary classification results to obtain the final classification result D10, so that the accuracy of the final classification result D10 can also be improved.

[0057] [Event Identification Unit Configuration Example: Example 3] 8 shows a third example of the configuration of the event discriminator 303. The event discriminator 303 in the figure includes one primary discriminator 334 and one secondary discriminator 335. The primary classifier 334 outputs a primary classification result according to the input of the time-series waveform information D1. The secondary classifier 335 outputs a final classification result D10 according to the input of the primary classification result output by the primary classifier 334, the time-series vibration position information D2, and the time-series frequency characteristic information D3.

[0058] That is, in the event identification unit 303 of this example, the primary classifier 334 is configured to output a primary identification result in response to input of a portion of all of the plurality of pieces of identification-use information. Also, the secondary classifier 335 is configured to output a final identification result D10 in response to input of the primary identification result output by the primary classifier 334 and the remaining identification-use information not input to the primary classifier 334 in all of the plurality of pieces of identification-use information.

[0059] In this example, the identification-use information input to the primary classifier 334 may be a part of all the plurality of pieces of identification-use information, and may be one or more. Furthermore, the one or more pieces of identification-use information input to the primary classifier 334 and the remaining identification-use information input to the secondary classifier 335 may be changed as appropriate depending on conditions such as the phenomenon to be identified.

[0060] In this example, for example, among the plurality of pieces of identification-use information, one or a plurality of pieces of basic identification-use information that are most suitable for identifying the phenomenon to be identified may be input to the primary classifier 334 to obtain a primary classification result. In addition, in this example, the secondary classifier 335 is constructed so that elements with low classification accuracy in the primary classification result of the primary classifier 334 can be appropriately reinforced with other identification-use information, making it possible to obtain a final classification result D10 with high accuracy.

[0061] [Application example of event identification system] A specific application example of the event identification system of this embodiment will be described with reference to Fig. 9. In Fig. 9, the same parts as those in Fig. 1 are given the same reference numerals and the description thereof will be omitted. In the event identification system shown in the figure, an optical fiber sensor 20 is buried under a road RD along which vehicles CR such as automobiles pass. 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 identification device 300, the information generating unit 302 generates identification use information (time series waveform information D1, time series vibration position information D2, and time series frequency characteristic information D3) by using the return light received by the receiving unit 301. The event identification unit 303 outputs a final identification result D10 according to the input of the identification use information.

[0062] In such an event identification system, the identification utilization information (time series waveform information D1, time series vibration position information D2, and time series frequency characteristic information D3) generated by the information generation unit 302 of the event identification device 300 can be treated as information detected regarding vibrations occurring in response to a vehicle passing over a road RD, for example. In addition, the event identification unit 303 can be configured to identify events such as the passing status of the vehicle CR on the road RD and road conditions in response to the input of the identification utilization information, and to output the final identification results D10 regarding these events. As a specific example, the event identification unit 303 may generate a final identification result D10 indicating the results of identifying the speed of each vehicle CR passing through the road RD, the type of each vehicle CR passing through the road RD (e.g., passenger car, freight vehicle, motorcycle, etc.), the weight and size of each vehicle CR passing through the road RD, the unevenness of the road RD, the situation of objects such as luggage falling onto the road RD, etc.

[0063] As the event identification unit 303 in the event identification system of Fig. 9, an identification algorithm that is deemed optimal among the configurations (identification algorithms) shown in Fig. 6 to Fig. 8 may be adopted depending on the event to be identified and various conditions in the environment to be identified. Furthermore, the event identification unit 303 may be configured to switch the identification algorithm depending on a change in the event to be identified and various conditions in the environment to be identified.

[0064] The time-series waveform information D1 has a larger amplitude as the object becomes harder, heavier, and faster. In addition, when the time-series waveform information D1 is graphed on two axes, time and amplitude, it has the characteristic that it becomes pulse-like when a moving object moving at a walking speed is identified, whereas it becomes envelope-like when a moving object moving at high speed such as a vehicle CR is identified. In addition, when the time-series vibration position information D2 is graphed on two axes of time and position, a slope can be obtained with high accuracy according to the speed. In addition, the time-series vibration position information D2 has a higher intensity as the speed increases. In addition, the time-series vibration position information D2 has a characteristic that it becomes dot-like when a moving object moving at a walking speed is identified, whereas it becomes line-like when a moving object moving at high speed such as a vehicle CR is identified. The time-series frequency characteristic information D3 responds to hard objects up to high frequencies. The time-series frequency characteristic information D3 also has a characteristic that the frequency feature amount is easily changed in response to a change in shape such as a depression in the road RD.

[0065] In addition, from the above characteristics, the advantages of identifying each phenomenon of abnormality occurrence such as the speed, the type of the vehicle CR, the position of the vehicle CR, and the step on the road RD for the time-series waveform information D1, the time-series vibration position information D2, and the time-series frequency characteristic information D3 are derived as follows. First, the time-series vibration position information D2 is best for identifying the speed, the time-series frequency characteristic information D3 is best for identifying the type of vehicle CR, the time-series vibration position information D2 is best for identifying the position of the vehicle CR, and the time-series frequency characteristic information D3 is best for identifying the occurrence of an abnormality.

[0066] Therefore, taking into consideration the advantages of each of the above identification utilization information, when the event identification system of FIG. 9 is configured to identify, for example, two objects, the speed of the vehicle CR and a step on the road RD, a identification algorithm may be constructed for the event identification unit 303 such that the time-series vibration position information D2 and the time-series frequency characteristic information D3 are identified with a higher weighting than the time-series waveform information D1.

[0067] In the event identification system of this embodiment, the events to be identified by the event identification device 300 are not limited to those based on distortion and vibration as described above. For example, the event identification device 300 may be configured to identify events related to temperature, dynamic pressure, and the like.

[0068] In this embodiment, the identification and use information generated by the information generating unit 302 is not limited to the three items of the time-series waveform information D1, the time-series vibration position information D2, and the time-series frequency characteristic information D3, and the information generating unit 302 may be configured to generate more identification and use information. As an example, the information generating unit 302 may also generate information indicating a change in the intensity of vibration over time instead of the amplitude of vibration, similar to the time-series waveform information D1.

[0069] <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.

[0070] 10 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.

[0071] When a structure has only one optical fiber 22, such as the optical fiber-supported sensor 30 in the same figure, the receiving unit 301 in the event identification device 300 may output one optical signal output from the one optical fiber 22 to the information generating unit 302 as an optical signal Sopt.

[0072] FIG. 11 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.

[0073] In the case of the optical fiber sensor 30A of this modified example, the receiving unit 301 may perform temperature compensation on the optical signal output from the optical fiber 22-1 using the optical signal output from the optical fiber 22-2, and output the temperature-compensated optical signal Sopt to the information generating unit 302.

[0074] In addition, a program for realizing the function of the above-mentioned event identification 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 identification 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. In addition, the "computer system" may include a plurality of computer devices connected via a network including the Internet, a WAN, a LAN, a dedicated line, and other communication lines. In addition, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, an optical magnetic disk, a ROM, a CD-ROM, and a storage device such as an HDD or an 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. In addition, 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]

[0075] 20, 20A, 30, 30A: Optical fiber-supported sensor; 21: Resin pipe; 22, 22-1, 22-2: Optical fiber; 31, 31-1, 31-2: Inner coating; 32: Outer coating; 300: Event classification device; 301: Receiving unit; 302: Information generating unit; 303: Event classification unit; 304: Memory unit; 331: Classifier; 332: Primary classifier; 332-1: Primary classifier; 332-2: Primary classifier; 332-3: Primary classifier; 333: Secondary classifier; 334: Primary classifier; 335: Secondary classifier; CR: Vehicle; D1: Time series waveform information; D2: Time series vibration position information; D3: Time series frequency characteristic information; D10: Final classification result

Claims

1. an information generating unit that can generate, as event identification information used for event identification based on an optical signal output from an optical fiber arranged in a predetermined environment, at least time-series vibration information indicating a change in vibration over time for each specific position, time-series vibration position information indicating a change in vibration position over time, and frequency characteristic information indicating a frequency characteristic of vibration in a unit time for each specific position; an event identification unit that performs identification regarding a predetermined event by using two or more pieces of identification-use information generated by the information generation unit; An event identification device comprising:

2. The event identification unit includes a plurality of primary classifiers each outputting a primary identification result in response to an input of any one of the plurality of pieces of identification-use information, and a secondary classifier outputting a final identification result in response to an input of the primary identification results output by each of the primary classifiers.

2. An event identifier as claimed in claim 1.

3. The event classification unit includes a single classifier that outputs a final classification result in response to input of all of the classification-use information.

2. An event identifier as claimed in claim 1.

4. The event identification unit includes a predetermined number of primary classifiers that output a primary identification result in response to an input of a part of a plurality of event use identification information, and a secondary classifier that outputs a final identification result in response to an input of the primary identification result and the event use identification information that is not input to the primary classifier.

2. An event identifier as claimed in claim 1.

5. an information generating step for generating, as event identification information to be used for event identification based on an optical signal output from an optical fiber arranged in a predetermined environment, at least time-series vibration information indicating a change in vibration over time for each specific position, time-series vibration position information indicating a change in vibration position over time, and frequency characteristic information indicating a frequency characteristic of vibration in a unit time for each specific position; an event identification step of identifying a predetermined event by using the two or more pieces of identification-use information generated by the information generation step; An event identification method comprising:

6. Computer, an information generating unit capable of generating, as event identification information used for event identification based on an optical signal output from an optical fiber arranged in a predetermined environment, at least time-series vibration information indicating a change in vibration over time for each specific position, time-series vibration position information indicating a change in vibration position over time, and frequency characteristic information indicating a frequency characteristic of vibration in a unit time for each specific position; an event identification unit that uses two or more pieces of identification-use information generated by the information generation unit to identify a predetermined event; A program to function as a

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