Sensing device, sensing system, sensing method, and program

Abstract

To monitor a state of a submarine cable or an environmental state around the submarine cable without depending on a diver or an ROV.SOLUTION: A sensing device according to the present disclosure includes reception means for receiving, from an optical fiber included in a submarine cable, backscattered light generated in the optical fiber, and specification means for specifying a state of the submarine cable or an environmental state around the submarine cable on the basis of the backscattered light.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a sensing device, a sensing system, a sensing method, and a program. [Background technology]

[0002] In offshore wind power generation, submarine cables are used to connect the offshore wind turbines and between the offshore wind turbines and onshore substations. The condition of the submarine cables and the environmental conditions around the submarine cables have traditionally been monitored visually by divers or by images taken by ROVs (Remotely Operated Vehicles), which are remotely operated unmanned underwater vehicles.

[0003] However, when using divers or ROVs to monitor the condition of submarine cables or the environmental conditions around them, there are problems such as the time and expense required to arrange for the divers or ROVs. Therefore, there has been a recent increase in demand for technology that can monitor the condition of submarine cables or the environmental conditions around submarine cables without using divers or ROVs.

[0004] Meanwhile, in recent years, there has been a technology that uses optical fiber to perform optical fiber sensing, such as distributed acoustic sensing (DAS) and distributed temperature sensing (DTS), to monitor the status of a monitored object. DAS detects vibrations or sounds around the optical fiber, while DTS detects the temperature around the optical fiber.

[0005] For example, Patent Document 1 discloses a technology in which an optical fiber installed on a steel tower together with a power transmission line is used to measure the vibration state at each measurement point with a DAS, and wind conditions (wind direction, wind speed) at each measurement point are obtained based on the vibration state at each measurement point. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2023 / 238348 Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, there has been a growing demand recently for technology that can monitor the condition of submarine cables or the environmental conditions around submarine cables without using divers or ROVs. It would be preferable if the technology disclosed in Patent Document 1 could be applied as such a technology.

[0008] However, the technology disclosed in Patent Document 1 uses optical fibers installed on steel towers, and therefore cannot be applied to monitoring the condition of submarine cables or the environmental conditions around the submarine cables.

[0009] In view of the above-mentioned problems, an object of the present disclosure is to provide a sensing device, a sensing system, a sensing method, and a program that are capable of monitoring the condition of a submarine cable or the environmental condition around the submarine cable without using a diver or an ROV. [Means for solving the problem]

[0010] A sensing device according to one aspect comprises: a receiving means for receiving backscattered light generated in an optical fiber contained in a submarine cable from the optical fiber; and an identification means for identifying the condition of the submarine cable or the environmental condition around the submarine cable based on the backscattered light.

[0011] A sensing system according to one aspect includes: a receiving means for receiving backscattered light generated in an optical fiber contained in a submarine cable from the optical fiber; and an identification means for identifying the condition of the submarine cable or the environmental condition around the submarine cable based on the backscattered light.

[0012] A sensing method according to one aspect includes: A sensing method performed by a sensing device, comprising: a receiving step of receiving backscattered light generated in an optical fiber included in a submarine cable from the optical fiber; and determining the state of the submarine cable or the environmental state around the submarine cable based on the backscattered light.

[0013] In one aspect, the program comprises: On the computer, a receiving step of receiving backscattered light generated in an optical fiber included in a submarine cable from said optical fiber; and executing an identification procedure for identifying the state of the submarine cable or the environmental state around the submarine cable based on the backscattered light. [Effects of the Invention]

[0014] According to the above-described aspects, it is possible to provide a sensing device, a sensing system, a sensing method, and a program that are capable of monitoring the condition of a submarine cable or the environmental condition around the submarine cable without using a diver or an ROV. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating an example of a facility for realizing offshore wind power generation. [Figure 2] FIG. 1 is a diagram illustrating a schematic configuration example of a sensing device according to the present disclosure. [Figure 3] 1 is a graph illustrating an example of a comparison of the change in temperature over time at a point where a submarine cable is buried in the seabed and at a point where the submarine cable is exposed in the sea. [Figure 4] 10 is a graph illustrating an example of a comparison of the temporal change in vibration intensity at two points at different depths where a submarine cable is buried in the seabed. [Figure 5] 10 is a graph illustrating an example of a comparison of the change in vibration intensity over time between normal times and when a submarine cable is moving at a point where the submarine cable is not buried in the seabed. [Figure 6] 1 is a graph illustrating an example of the change over time in vibration intensity at a point where a submarine cable is buried in the seabed. [Figure 7] FIG. 10 is a flowchart illustrating an example of a schematic operation flow of a sensing device according to the present disclosure. [Figure 8] FIG. 1 is a diagram illustrating a schematic configuration example of a sensing device according to the present disclosure. [Figure 9] FIG. 1 is a diagram illustrating a schematic configuration example of a sensing system according to the present disclosure. [Figure 10] FIG. 1 is a block diagram illustrating a schematic hardware configuration example of a computer that realizes a sensing device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description and drawings have been omitted and simplified as appropriate for clarity of explanation. In addition, in each of the following drawings, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary. Furthermore, specific numerical values ​​shown below are merely examples to facilitate understanding of the present disclosure, and are not limited thereto.

[0017] <Offshore wind power generation facilities> Before describing each embodiment of the present disclosure, an offshore wind power generation facility to which the present disclosure is applied will be described.

[0018] FIG. 1 is a diagram showing an example of a facility for realizing offshore wind power generation. As shown in Figure 1, in offshore wind power generation, wind turbines 40X, 40Y, and 40Z are installed offshore, and a substation 50 is installed on land. Hereinafter, when it is not necessary to specify which wind turbine 40X, 40Y, or 40Z is being referred to, it will be simply referred to as "wind turbine 40." Furthermore, the number of wind turbines 40 is not limited to three, and may be one or more.

[0019] Furthermore, the wind turbines 40 are connected to the substations 50 and among the wind turbines 40 by power transmission lines (not shown) and submarine cables 30 containing optical fibers 20, and power is transmitted via the power transmission lines, while communication is carried out via the optical fibers 20. The number of optical fibers 20 contained in the submarine cables 30 may be one or more.

[0020] The submarine cable 30 is mostly buried in the seabed, but in the vicinity of the wind turbines 40, the submarine cable 30 is pulled up from the seabed and exposed in the sea, or is laid inside the wind turbines 40.

[0021] In each embodiment described below, the condition of the submarine cable 30 or the environmental condition around the submarine cable 30 is identified by performing optical fiber sensing using the optical fiber 20 contained in the submarine cable 30.

[0022] <First Embodiment> FIG. 2 is a diagram showing a schematic configuration example of a sensing device 10 according to the present disclosure. 2, the sensing device 10 includes an optical fiber housing box 11, a DAS unit 12, a DTS unit 13, and an analysis unit 14. For example, the sensing device 10 is disposed inside a substation 50, but the location of the sensing device 10 is not limited to this.

[0023] The optical fiber housing box 11 houses the optical fibers 20 contained in the submarine cable 30. Figure 2 shows an example in which seven optical fibers 20 are contained in the submarine cable 30. Therefore, the optical fiber housing box 11 houses the seven optical fibers 20.

[0024] The DAS unit 12 is connected to one of the optical fibers 20 housed in the optical fiber housing box 11, and executes DAS to detect vibrations or sounds around the submarine cable 30 using the connected optical fiber 20. It is preferable that the optical fiber 20 connected to the DAS unit 12 is an unused optical fiber 20 that is not used for communication.

[0025] The DTS unit 13 is connected to one of the optical fibers 20 housed in the optical fiber housing box 11, and executes DTS to detect the temperature around the submarine cable 30 using the connected optical fiber 20. It is preferable that the optical fiber 20 connected to the DTS unit 13 is an unused optical fiber 20 that is not used for communication.

[0026] In this case, separate optical fibers 20 may be connected to the DAS unit 12 and the DTS unit 13, and the DAS unit 12 and the DTS unit 13 may perform sensing simultaneously. Alternatively, the same optical fiber 20 may be alternately connected to the DAS unit 12 and the DTS unit 13, and the DAS unit 12 and the DTS unit 13 may perform sensing alternately.

[0027] When performing DAS, the DAS unit 12 outputs pulsed light to the optical fiber 20. As the pulsed light is transmitted through the optical fiber 20, backscattered light is generated in the optical fiber 20, and the DAS unit 12 receives this backscattered light.

[0028] Here, when vibrations or sounds occur around the submarine cable 30, the characteristics (e.g., wavelength) of the backscattered light (more specifically, Raman scattered light or Brillouin scattered light among the backscattered light) transmitted through the optical fiber 20 change. Therefore, the DAS unit 12 can detect vibrations or sounds occurring around the submarine cable 30. Furthermore, the DAS unit 12 can calculate the vibration intensity or sound intensity based on the degree of change in the characteristics of the backscattered light.

[0029] In addition, the DAS unit 12 can identify the position (distance from the DAS unit 12) of the point where the backscattered light was generated based on the time difference between the time when the pulsed light was output and the time when the backscattered light was received.

[0030] Therefore, the DAS unit 12 can identify, for each point on the submarine cable 30, the change over time in the vibration intensity of the vibration or the sound intensity of the sound generated around that point.

[0031] On the other hand, when executing DTS, the DTS unit 13 outputs pulsed light to the optical fiber 20. As the pulsed light is transmitted through the optical fiber 20, backscattered light is generated in the optical fiber 20, and the DTS unit 13 receives this backscattered light.

[0032] Here, when a temperature change occurs around the submarine cable 30, the characteristics (for example, wavelength) of the backscattered light (more specifically, Rayleigh scattered light among the backscattered light) transmitted through the optical fiber 20 change. Therefore, the DTS unit 13 can detect temperature changes occurring around the submarine cable 30. Furthermore, the DAS unit 12 can calculate the degree of temperature change based on the degree of change in the characteristics of the backscattered light. Therefore, if the absolute value of the temperature in the initial state is set in advance, the DTS unit 13 can calculate the temperature from the temperature in the initial state and the degree of temperature change thereafter.

[0033] In addition, the DTS unit 13 can identify the position (distance from the DTS unit 13) of the point where the backscattered light was generated based on the time difference between the time the pulsed light was output and the time the backscattered light was received.

[0034] Therefore, the DTS unit 13 can identify the change in temperature around each point on the submarine cable 30 over time.

[0035] The analysis unit 14 determines the condition of the submarine cable 30 or the environmental condition around the submarine cable 30 based on the backscattered light received by the DAS unit 12 and the DTS unit 13 .

[0036] Specifically, the analysis unit 14 determines the condition of the submarine cable 30 at each point on the submarine cable 30 or the environmental condition around that point based on the time changes of at least one of the vibration intensity, sound intensity, and temperature at that point, which are determined by the DAS unit 12 and the DTS unit 13 based on the backscattered light.

[0037] The analysis unit 14 will be described in detail below. Fig. 3 is a graph illustrating an example of a comparison of the change in temperature over time between a point where the submarine cable 30 is buried in the seabed and a point where the submarine cable 30 is exposed in the sea. In Fig. 3, the horizontal axis represents time and the vertical axis represents temperature.

[0038] As shown in Figure 3, it can be seen that the temperature changes over time are different at the point where the submarine cable 30 is buried in the seabed and the point where the submarine cable 30 is exposed to the sea. Furthermore, although not shown, the inventors have also confirmed that the temperature changes over time are different at the point where the submarine cable 30 is buried in the seabed and the point where the submarine cable 30 is laid inside the wind turbine 40.

[0039] Therefore, based on the change in temperature over time at each point on the submarine cable 30, the analysis unit 14 determines whether the submarine cable 30 is buried in the seabed at that point as the state of the submarine cable 30 at that point.

[0040] Fig. 4 is a graph illustrating an example of a comparison of the change in vibration intensity over time at two different depths of the submarine cable 30 buried in the seabed. In Fig. 4, the horizontal axis represents time and the vertical axis represents vibration intensity.

[0041] As shown in Figure 4, it can be seen that the time change of vibration intensity differs between two points at different depths among the points where the submarine cable 30 is buried in the seabed. Furthermore, although not shown, the inventors have also confirmed that the time change of sound intensity differs between the two points at different depths.

[0042] Therefore, the analysis unit 14 determines the depth of the submarine cable 30 at each point, based on the change over time in vibration intensity or sound intensity at each point on the submarine cable 30 that is buried in the seabed, as the state of the submarine cable 30 at that point.

[0043] Fig. 5 is a graph illustrating an example of a comparison of the change in vibration intensity over time between normal times and when the submarine cable 30 is moving at a point where the submarine cable 30 is not buried in the seabed (for example, a point in the unburied section near wind turbines 40X and 40Y in Fig. 1). In Fig. 5, the horizontal axis represents time and the vertical axis represents vibration intensity.

[0044] As shown in Figure 5, at a point where the submarine cable 30 is not buried in the seabed, it can be seen that the change in vibration intensity over time is different between normal times and when the submarine cable 30 is moving. Furthermore, although not shown, the inventors have also confirmed that the change in sound intensity over time is different between normal times and when the submarine cable 30 is moving.

[0045] Therefore, the analysis unit 14 determines whether the submarine cable 30 is moving at each point based on the change over time in vibration intensity or sound intensity at each point on the submarine cable 30 that is not buried in the seabed, as the state of the submarine cable 30 at that point.

[0046] Furthermore, although not shown, the present inventors have also confirmed that at a point where the submarine cable 30 is not buried in the seabed, the change over time in vibration intensity or sound intensity differs between normal times and when the submarine cable 30 is colliding with a surrounding object.

[0047] Therefore, the analysis unit 14 determines whether the submarine cable 30 is colliding with a surrounding object at each point on the submarine cable 30 based on the change over time in vibration intensity or sound intensity at each point on the submarine cable 30 that is not buried in the seabed, as the state of the submarine cable 30 at that point.

[0048] Fig. 6 is a graph illustrating an example of the change over time in vibration intensity at a point where the submarine cable 30 is buried in the seabed (for example, in Fig. 1, a point offshore such as the buried section between wind turbines 40Y and 40Z or the buried section between wind turbines 40X and 40Y). In Fig. 6, the horizontal axis represents time, and the vertical axis represents vibration intensity.

[0049] As shown in Figure 6, the change over time in vibration intensity at the point where the submarine cable 30 is buried in the seabed corresponds to the wave height. Although not shown, the inventors have also confirmed that the change over time in vibration intensity at the above point corresponds to the wave period. The inventors have also confirmed that the change over time in sound intensity at the above point corresponds to the wave height and period.

[0050] Therefore, the analysis unit 14 identifies the wave conditions (wave height and period) around each point as the environmental condition around that point based on the change over time in vibration intensity or sound intensity at each point on the submarine cable 30 that is buried in the seabed.

[0051] The analysis unit 14 may use pattern matching or a learning model to identify the condition of the submarine cable 30 at each point on the submarine cable 30 or the environmental condition around that point based on the time change of at least one of the vibration intensity, sound intensity, and temperature at that point.

[0052] Below, a method using pattern matching or a learning model will be explained, taking as an example a case where it is determined whether or not the submarine cable 30 is buried in the seabed at a point on the submarine cable 30 based on the change in temperature over time at that point.

[0053] When pattern matching is used, the analysis unit 14 stores in advance, as a matching pattern, a pattern that indicates the change over time in temperature at a point where the submarine cable 30 is buried in the seabed. Note that it is sufficient for the analysis unit 14 to store one or more matching patterns. Then, when the analysis unit 14 obtains the change over time in temperature at an arbitrary point, it compares the pattern of the change over time with the matching pattern. If there is a matching pattern whose compatibility rate is equal to or exceeds a threshold, the analysis unit 14 determines that the arbitrary point is a point where the submarine cable 30 is buried in the seabed. Note that the matching pattern may also be a pattern that indicates the change over time in temperature at a point where the submarine cable 30 is not buried in the seabed.

[0054] Furthermore, when using a learning model, the analysis unit 14 inputs a plurality of pairs of training data indicating whether or not a point is buried in the seabed and a pattern indicating the temperature change over time at that point, and constructs and stores the learning model in advance. Then, when the analysis unit 14 obtains the temperature change over time at an arbitrary point, it inputs the pattern of the time change into the learning model. As a result, the analysis unit 14 obtains, as an output result of the learning model, a result indicating whether or not the arbitrary point is a point where the submarine cable 30 is buried in the seabed.

[0055] The matching patterns and learning models are not limited to being held by the analysis unit 14. For example, any component inside or outside the sensing device 10 may hold the matching patterns and learning models, and the analysis unit 14 may read and use the matching patterns and learning models.

[0056] 7 is a flow diagram illustrating an example of a schematic operation flow of the sensing device 10 according to the present disclosure. Here, it is assumed that the DAS unit 12 and the DTS unit 13 perform sensing simultaneously.

[0057] As shown in FIG. 7, the DAS unit 12 and the DTS unit 13 output pulsed light to the optical fiber 20 contained in the submarine cable 30, and receive backscattered light from the optical fiber 20 that is generated as the pulsed light is transmitted through the optical fiber 20 (step S11).

[0058] The analysis unit 14 identifies the state of the submarine cable 30 or the environmental state around the submarine cable 30 based on the backscattered light received by the DAS unit 12 and the DTS unit 13 (step S12).

[0059] At this time, the DAS unit 12 and the DTS unit 13 may determine, based on the backscattered light, a change over time in at least one of vibration intensity, sound intensity, and temperature at each point on the submarine cable 30. Then, the analysis unit 14 may determine, based on the change over time in at least one of vibration intensity, sound intensity, and temperature at each point on the submarine cable 30, the condition of the submarine cable 30 at that point or the environmental condition around that point.

[0060] As described above, according to the first embodiment, the DAS unit 12 and the DTS unit 13 receive backscattered light generated in the optical fiber 20 contained in the submarine cable 30 from the optical fiber 20. The analysis unit 14 identifies the state of the submarine cable 30 or the environmental state around the submarine cable 30 based on the backscattered light received by the DAS unit 12 and the DTS unit 13.

[0061] As a result, the first embodiment makes it possible to monitor the condition of the submarine cable 30 or the environmental condition around the submarine cable 30 without using a diver or an ROV. Furthermore, since the optical fiber 20 contained in the submarine cable 30 is used, it is possible to use the existing submarine cable 30 as is. Therefore, no major modifications are required to introduce the means according to the present disclosure, and the barrier to introduction is low.

[0062] Furthermore, when monitoring is carried out by divers or ROVs, the following problems arise. - Arranging for divers or ROVs takes time and money, making it difficult to monitor frequently. In particular, monitoring is not possible in winter due to environmental factors such as the seawater temperature and rough waves, so monitoring must wait until early spring. As a result, there are periods throughout the year when monitoring is not possible. When monitoring the condition of the submarine cable 30, the entire submarine cable 30 must be visually inspected thoroughly, which takes time to identify any abnormalities. As a result, the detection of the abnormality may be delayed, which may lead to, for example, the shutdown of the wind turbine 40. If the wind turbine 40 is shut down, enormous restoration costs and losses will occur.

[0063] In contrast, in the first embodiment, monitoring is performed based on backscattered light generated in the optical fiber 20 contained in the submarine cable 30, so monitoring is possible all year round and abnormal locations can also be detected early. As a result, the possibility of the wind turbine 40 being shut down is reduced, and therefore the possibility of restoration costs and losses occurring is also reduced.

[0064] In the first embodiment, the analysis unit 14 determines the state of the submarine cable 30 at each point on the submarine cable 30 or the environmental conditions around that point based on the time variation of at least one of the vibration intensity, sound intensity, and temperature at that point, which are determined based on the backscattered light. However, this is not limiting. The analysis unit 14 may also determine a feature quantity obtained by processing at least one of the vibration intensity, sound intensity, and temperature at that point on the submarine cable 30. Here, processing refers to performing statistical processing (averaging, normalization, etc.) or frequency analysis (FFT (Fast Fourier Transform), etc.) on at least one of the vibration intensity, sound intensity, and temperature. Processing enables accurate monitoring, thereby improving monitoring accuracy. The analysis unit 14 may then determine the state of the submarine cable 30 at that point or the environmental conditions around that point based on the feature quantity at that point on the submarine cable 30. Therefore, the vertical axes of the graphs shown in FIGS. 3 to 6 may represent feature quantities.

[0065] <Embodiment 2> The second embodiment corresponds to an embodiment that is a higher-level concept of the above-described embodiments. FIG. 8 is a diagram showing a schematic configuration example of a sensing device 10A according to the present disclosure. As shown in FIG. 8, the sensing device 10A includes a receiving unit 15 and an identifying unit 16.

[0066] The receiving unit 15 receives backscattered light generated in the optical fiber 20 contained in the submarine cable 30 from the optical fiber 20. The receiving unit 15 is realized by some functions of the DAS unit 12 and the DTS unit 13.

[0067] The identification unit 16 identifies the state of the submarine cable 30 or the environmental state around the submarine cable 30 based on the backscattered light received by the receiving unit 15. The identification unit 16 is realized by the analysis unit 14 and some functions of the DAS unit 12 and the DTS unit 13.

[0068] As a result, in the second embodiment, it becomes possible to monitor the state of the submarine cable 30 or the environmental state around the submarine cable 30 without using a diver or an ROV.

[0069] The identifying unit 16 may use the backscattered light to identify, for each point on the submarine cable 30, a change over time in at least one of the vibration intensity, sound intensity, and temperature around that point. Furthermore, the identifying unit 16 may use the change over time in at least one of the vibration intensity, sound intensity, and temperature around that point on the submarine cable 30 to identify the state of the submarine cable 30 at that point or the environmental state around that point.

[0070] The identifying unit 16 may also identify the change in temperature over time at each point on the submarine cable 30. Furthermore, based on the change in temperature over time at each point on the submarine cable 30, the identifying unit 16 may identify whether or not the submarine cable 30 is buried in the seabed at that point as the state of the submarine cable 30 at that point.

[0071] The identifying unit 16 may also identify the change over time in vibration intensity or sound intensity for each point on the submarine cable 30. Furthermore, the identifying unit 16 may identify the depth of the submarine cable 30 at each point, as the state of the submarine cable 30 at that point, based on the change over time in vibration intensity or sound intensity for each point on the submarine cable 30 that is buried in the seabed.

[0072] The identifying unit 16 may also identify the change over time in vibration intensity or sound intensity for each point on the submarine cable 30. Furthermore, the identifying unit 16 may identify whether or not the submarine cable 30 is moving at each point, as the state of the submarine cable 30 at that point, based on the change over time in vibration intensity or sound intensity for each point on the submarine cable 30 that is not buried in the seabed.

[0073] The identifying unit 16 may also identify the change over time in vibration intensity or sound intensity for each point on the submarine cable 30. Furthermore, the identifying unit 16 may identify, based on the change over time in vibration intensity or sound intensity for each point on the submarine cable 30 that is not buried in the seabed, whether or not the submarine cable 30 is colliding with a surrounding object at that point, as the state of the submarine cable 30 at that point.

[0074] The identifying unit 16 may also identify the change over time in vibration intensity or sound intensity for each point on the submarine cable 30. Furthermore, the identifying unit 16 may identify the wave conditions around each point as the environmental condition around that point, based on the change over time in vibration intensity or sound intensity for each point on the submarine cable 30 that is buried in the seabed.

[0075] Furthermore, the identifying unit 16 may identify, based on the backscattered light, a feature quantity obtained by processing at least one of the vibration intensity, sound intensity, and temperature around each point on the submarine cable 30. Furthermore, based on the feature quantity for each point on the submarine cable 30, the identifying unit 16 may identify the condition of the submarine cable 30 at that point or the environmental condition around that point.

[0076] <Third Embodiment> FIG. 9 is a diagram showing a schematic configuration example of a sensing system 10B according to the present disclosure. As shown in FIG. 9, the sensing system 10B includes a receiving unit 15 and an identifying unit 16.

[0077] In the sensing system 10B, the receiving unit 15 and the identifying unit 16 are provided separately. For example, the receiving unit 15 may be provided in a sensing device such as the sensing device 10A. On the other hand, the identifying unit 16 may be provided in a device separate from the receiving unit 15, or may be provided on the cloud.

[0078] The third embodiment is similar to the second embodiment described above, except that the receiving unit 15 and the identifying unit 16 are separated. Therefore, detailed descriptions of the configuration, operation, and effects of the third embodiment will be omitted below.

[0079] <Hardware configuration of the sensing device> FIG. 10 is a block diagram showing an example of a schematic hardware configuration of a computer 90 that realizes the sensing device 10, 10A according to the present disclosure.

[0080] 10, a computer 90 includes a processor 91, a memory 92, a storage 93, an input / output interface (input / output I / F) 94, and a communication interface (communication I / F) 95. The processor 91, the memory 92, the storage 93, the input / output interface 94, and the communication interface 95 are connected by a data transmission path for transmitting and receiving data to and from each other.

[0081] The processor 91 is, for example, an arithmetic processing device such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The memory 92 is, for example, a memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory). The storage 93 is, for example, a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a memory card. The storage 93 may also be a memory such as a RAM or a ROM.

[0082] A program is stored in the storage 93. When the program is loaded into a computer, it includes a set of instructions (or software code) that causes the computer 90 to perform one or more functions of the sensing device 10, 10A described above. The components of the sensing device 10, 10A described above may be realized by the processor 91 reading and executing a program stored in the storage 93. Furthermore, the storage function of the sensing device 10, 10A described above may be realized by the memory 92 or the storage 93.

[0083] The above-described programs may also be stored on non-transitory computer-readable media or tangible storage media. By way of example and not limitation, computer-readable media or tangible storage media include RAM, ROM, flash memory, SSD or other memory technology, CD (Compact Disc)-ROM, DVD (Digital Versatile Disc), Blu-ray® disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices. The programs may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0084] The input / output interface 94 is connected to a display device 941, an input device 942, a sound output device 943, etc. The display device 941 is a device that displays a screen corresponding to drawing data processed by the processor 91, such as an LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube) display, or a monitor. The input device 942 is a device that accepts operational inputs from an operator, such as a keyboard, a mouse, or a touch sensor. The display device 941 and the input device 942 may be integrated and realized as a touch panel. The sound output device 943 is a device that outputs sound corresponding to audio data processed by the processor 91, such as a speaker.

[0085] The communication interface 95 transmits and receives data to and from an external device. For example, the communication interface 95 communicates with the external device via a wired communication path or a wireless communication path.

[0086] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0087] Furthermore, each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessarily required to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0088] Furthermore, some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes. (Appendix 1) a receiving means for receiving backscattered light generated in an optical fiber contained in a submarine cable from the optical fiber; and an identification means for identifying the condition of the submarine cable or the environmental condition around the submarine cable based on the backscattered light. Sensing device. (Appendix 2) The identification means determining, for each point on the submarine cable, a time change in at least one of vibration intensity, sound intensity, and temperature around the point, based on the backscattered light; determining the condition of the submarine cable at each point on the submarine cable or the environmental condition around the point on the basis of the time variation of at least one of the vibration intensity, the sound intensity, and the temperature at the point on the submarine cable; 2. The sensing device of claim 1. (Appendix 3) The identification means Identifying the temperature change over time at each point on the submarine cable; determining whether or not the submarine cable is buried in the seabed at each point on the submarine cable based on the change in temperature over time at each point on the submarine cable, as the state of the submarine cable at that point; 3. The sensing device of claim 2. (Appendix 4) The identification means Identifying the change over time of the vibration intensity or the sound intensity for each point on the submarine cable; specifying the depth of the submarine cable at each point buried in the seabed based on the change over time of the vibration intensity or the sound intensity at each point on the submarine cable as the state of the submarine cable at that point; 4. The sensing device of claim 3. (Appendix 5) The identification means Identifying the change over time of the vibration intensity or the sound intensity for each point on the submarine cable; determining whether the submarine cable is moving at each point on the submarine cable based on the change over time in the vibration intensity or the sound intensity at each point that is not buried in the seabed among the points on the submarine cable; 4. The sensing device of claim 3. (Appendix 6) The identification means Identifying the change over time of the vibration intensity or the sound intensity for each point on the submarine cable; determining whether the submarine cable is colliding with a surrounding object at each point on the submarine cable based on the change over time in the vibration intensity or the sound intensity at each point that is not buried in the seabed among the points on the submarine cable; 4. The sensing device of claim 3. (Appendix 7) The identification means Identifying the change over time of the vibration intensity or the sound intensity for each point on the submarine cable; and identifying the wave conditions around each point buried in the seabed among the points on the submarine cable based on the time change of the vibration intensity or the sound intensity for each point as the environmental condition around the point. 4. The sensing device of claim 3. (Appendix 8) The identification means identifying, for each point on the submarine cable, a feature obtained by processing at least one of vibration intensity, sound intensity, and temperature around the point, based on the backscattered light; identifying the state of the submarine cable at each point on the submarine cable or the environmental state around the point on the basis of the feature amount for each point on the submarine cable; 2. The sensing device of claim 1. (Appendix 9) a receiving means for receiving backscattered light generated in an optical fiber contained in a submarine cable from the optical fiber; and an identification means for identifying the condition of the submarine cable or the environmental condition around the submarine cable based on the backscattered light. Sensing system. (Appendix 10) A sensing method performed by a sensing device, comprising: a receiving step of receiving backscattered light generated in an optical fiber included in a submarine cable from the optical fiber; and determining a state of the submarine cable or an environmental state around the submarine cable based on the backscattered light. Sensing method. (Appendix 11) On the computer, a receiving step of receiving backscattered light generated in an optical fiber included in a submarine cable from said optical fiber; and executing an identification procedure for identifying the state of the submarine cable or the environmental state around the submarine cable based on the backscattered light. program.

[0089] Note that some or all of the elements (e.g., configurations and functions) described in Supplements 2 to 8 that are dependent on Supplement 1 may also be dependent on Supplements 9 to 11 in the same dependency relationship as Supplements 2 to 8. Some or all of the elements described in any Supplement may be applied to various hardware, software, recording means for recording software, systems, and methods. [Explanation of symbols]

[0090] 10,10A sensing device 10B Sensing System 11 Optical fiber storage box 12 DAS units 13 DTS unit 14 Analysis Department 15 Receiving unit 16 Specific section 20 Optical Fiber 30 Submarine Cable 40X, 40Y, 40Z Windmill 50 substations 90 Computer 91 processors 92 memory 93 Storage 94 Input / Output Interface 941 Display device 942 Input Device 943 Sound Output Device 95 Communication Interface

Claims

1. a receiving means for receiving backscattered light generated in an optical fiber contained in a submarine cable from the optical fiber; and an identification means for identifying the condition of the submarine cable or the environmental condition around the submarine cable based on the backscattered light. Sensing device.

2. The identification means determining, for each point on the submarine cable, a time change in at least one of vibration intensity, sound intensity, and temperature around the point, based on the backscattered light; determining a state of the submarine cable at each point on the submarine cable or an environmental state around the point on the basis of a time change in at least one of the vibration intensity, the sound intensity, and the temperature at the point on the submarine cable; The sensing device according to claim 1 .

3. The identification means Identifying the temperature change over time at each point on the submarine cable; determining whether or not the submarine cable is buried in the seabed at each point on the submarine cable based on the change in temperature over time at each point on the submarine cable, as the state of the submarine cable at that point; The sensing device according to claim 2 .

4. The identification means Identifying the change over time of the vibration intensity or the sound intensity for each point on the submarine cable; specifying the depth of the submarine cable at each point buried in the seabed based on the change over time of the vibration intensity or the sound intensity at each point on the submarine cable as the state of the submarine cable at that point; The sensing device according to claim 3 .

5. The identification means Identifying the change over time of the vibration intensity or the sound intensity for each point on the submarine cable; determining whether the submarine cable is moving at each point on the submarine cable based on the change over time in the vibration intensity or the sound intensity at each point that is not buried in the seabed among the points on the submarine cable; The sensing device according to claim 3 .

6. The identification means Identifying the change over time of the vibration intensity or the sound intensity for each point on the submarine cable; determining whether the submarine cable is colliding with a surrounding object at each point on the submarine cable based on the change over time in the vibration intensity or the sound intensity at each point that is not buried in the seabed among the points on the submarine cable; The sensing device according to claim 3 .

7. The identification means identifying, for each point on the submarine cable, a feature obtained by processing at least one of vibration intensity, sound intensity, and temperature around the point, based on the backscattered light; identifying the state of the submarine cable at each point on the submarine cable or the environmental state around the point based on the feature amount for each point on the submarine cable; The sensing device according to claim 1 .

8. a receiving means for receiving backscattered light generated in an optical fiber contained in a submarine cable from the optical fiber; and an identification means for identifying the condition of the submarine cable or the environmental condition around the submarine cable based on the backscattered light. Sensing system.

9. A sensing method performed by a sensing device, comprising: a receiving step of receiving backscattered light generated in an optical fiber included in a submarine cable from the optical fiber; and determining a state of the submarine cable or an environmental state around the submarine cable based on the backscattered light. Sensing method.

10. On the computer, a receiving step of receiving backscattered light generated in an optical fiber included in a submarine cable from said optical fiber; and executing an identification procedure for identifying the state of the submarine cable or the environmental state around the submarine cable based on the backscattered light. program.

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