WO2022176047A1 - 電柱位置特定方法及び架空光ファイバケーブルの状態推定方法 - Google Patents

電柱位置特定方法及び架空光ファイバケーブルの状態推定方法 Download PDF

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Publication number
WO2022176047A1
WO2022176047A1 PCT/JP2021/005852 JP2021005852W WO2022176047A1 WO 2022176047 A1 WO2022176047 A1 WO 2022176047A1 JP 2021005852 W JP2021005852 W JP 2021005852W WO 2022176047 A1 WO2022176047 A1 WO 2022176047A1
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WO
WIPO (PCT)
Prior art keywords
optical fiber
vibration
utility pole
vibration distribution
fiber cable
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Ceased
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PCT/JP2021/005852
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English (en)
French (fr)
Japanese (ja)
Inventor
達也 岡本
大輔 飯田
優介 古敷谷
奈月 本田
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NTT Inc
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Nippon Telegraph and Telephone Corp
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Publication date
Application filed by Nippon Telegraph and Telephone Corp filed Critical Nippon Telegraph and Telephone Corp
Priority to JP2023500173A priority Critical patent/JP7491458B2/ja
Priority to PCT/JP2021/005852 priority patent/WO2022176047A1/ja
Priority to EP21926487.6A priority patent/EP4296633A4/en
Priority to CN202180093496.XA priority patent/CN116917703A/zh
Priority to US18/275,726 priority patent/US12553769B2/en
Publication of WO2022176047A1 publication Critical patent/WO2022176047A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
    • G01H9/004—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means using fibre optic sensors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/14—Measuring arrangements characterised by the use of optical techniques for measuring distance or clearance between spaced objects or spaced apertures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
    • G01D5/35338—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using other arrangements than interferometer arrangements
    • G01D5/35354—Sensor working in reflection
    • G01D5/35358—Sensor working in reflection using backscattering to detect the measured quantity
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/46—Processes or apparatus adapted for installing or repairing optical fibres or optical cables
    • G02B6/48—Overhead installation
    • G02B6/483—Installation of aerial type

Definitions

  • the present invention relates to a method for identifying the position of a utility pole and a method for estimating the state of an overhead optical fiber cable using an optical fiber vibration distribution measurement method.
  • Non-Patent Document 1 A method of intentionally applying vibration to an optical fiber cable has been proposed in order to compare the installation position (see, for example, Non-Patent Document 1 and Non-Patent Document 2).
  • the methods described in Non-Patent Literature 1 and Non-Patent Literature 2 apply vibration to an optical fiber cable or the like, and measure the temporal change of scattered light at a specific position by a light pulse test method.
  • an object of the present disclosure is to provide a method for remotely identifying the position of a utility pole and estimating the state of an overhead optical fiber cable.
  • an optical fiber vibration distribution measurement method (DAS: Distributed Acoustic Sensing) is used to identify the utility pole position from the vibration distribution pattern with respect to the optical fiber distance. , to estimate the condition of the aerial fiber optic cable.
  • DAS Distributed Acoustic Sensing
  • the utility pole position identification method of the present disclosure is based on the vibration distribution pattern obtained by sequentially accumulating the amount of strain with respect to the distance of the optical fiber measured by the optical fiber vibration distribution measurement method. It is characterized by specifying that
  • the method for estimating the state of an aerial optical fiber cable of the present disclosure is based on a vibration distribution pattern obtained by sequentially accumulating the amount of strain with respect to the optical fiber distance in the utility pole span measured by the optical fiber vibration distribution measurement method. propagates along the optical fiber and the amplitude of the vibration is uniform, it is determined that the optical fiber cable is normal.
  • the method for estimating the state of an aerial optical fiber cable of the present disclosure is based on a vibration distribution pattern obtained by sequentially accumulating the amount of strain with respect to the optical fiber distance in the utility pole span measured by the optical fiber vibration distribution measurement method. is propagated along the optical fiber and the amplitude of the vibration is not uniform, it is determined that the optical fiber cable has a load due to deposits.
  • the method for estimating the state of an aerial optical fiber cable of the present disclosure is based on a vibration distribution pattern obtained by sequentially accumulating the amount of strain with respect to the optical fiber distance in the utility pole span measured by the optical fiber vibration distribution measurement method. is stopped or reduced in the middle of the optical fiber, it is determined that an obstacle on the ground is in contact with the optical fiber cable.
  • FIG. 4 is a diagram showing a vibration distribution pattern of an optical fiber
  • FIG. 4 is a diagram showing a vibration distribution pattern of an optical fiber
  • FIG. 4 is a diagram showing a vibration distribution pattern of an optical fiber
  • FIG. 4 is a diagram showing a vibration distribution pattern of an optical fiber
  • FIG. 1 is a schematic diagram showing how a DAS is used to specify the position of a utility pole from the vibration distribution pattern with respect to the optical fiber distance, and how an aerial optical fiber cable is installed.
  • An optical signal is input to an optical cable from an optical fiber vibration distribution measuring device installed in a communication building.
  • An optical signal propagates from an optical fiber cable laid underground to an optical fiber cable laid overhead. Rayleigh scattering is induced in the optical fiber while propagating, and part of the Rayleigh scattered light scattered toward the optical fiber vibration distribution measuring apparatus returns as backscattered light.
  • OTDR Optical Time Domain Reflectometer
  • OFDR Optical Frequency Domain Reflectometer
  • the vibration frequency of an overhead optical fiber cable is 10 Hz or less and the wavelength is about 2 m.
  • the measurement performance required for the backscattered light measuring means is a sampling frequency of 20 Hz or more and a spatial resolution of about 1 m.
  • C-OTDR Coherent OTDR
  • OFDR Optical Frequency Domain Reflectometer
  • the DAS of this embodiment uses an OFDR (Optical Frequency Domain Reflectometer) as backscattered light measuring means to measure the backscattered light waveform with respect to the distance Z of the optical fiber cable.
  • OFDR Optical Frequency Domain Reflectometer
  • FIG. 2 first, the backscattered light intensity with respect to the distance of the optical fiber cable, which is the "reference measurement”, is acquired, and the "first measurement”, “second measurement”, ... " The backscattered light waveforms for the n-th measurement are sequentially acquired.
  • the waveforms at the distance between Z1 and Z2 are subjected to spectrum analysis (Fourier transform) and the spectrum shift is calculated to obtain the spectrum waveforms shown in FIG.
  • the spectrum obtained during the reference measurement is used as a reference waveform, the cross-correlation with the spectrum at each time is calculated, and the spectral shift that gives the cross-correlation peak is calculated.
  • spectral shifts are calculated in the order of "reference measurement”, "first measurement”, and "second measurement”.
  • the spectral shift ⁇ is represented by the following equation by modifying the equation (8) of Non-Patent Document 3.
  • ⁇ ⁇ 0.78* ⁇ * ⁇ 0 (1)
  • ⁇ is the amount of distortion
  • ⁇ 0 is the center frequency of the probe light.
  • the amount of spectral shift with respect to distance is represented by black and white shading, and by accumulating sequentially for each time, the vibration distribution pattern of the optical fiber as shown in Fig. 4 can be obtained.
  • a portion with positive strain indicates that the optical fiber is stretched, and a portion with negative strain indicates that the optical fiber is compressed.
  • positive distortion portions are represented by white and negative distortion portions are represented by black. It may also be represented by shades of different colors.
  • An overhead optical fiber cable can be regarded as a string that vibrates uniquely for each utility pole span.
  • the wind-induced vibration propagates through the utility pole span over time, and the amplitude and propagation speed of the vibration differ from one utility pole span to another. Therefore, it was found that each utility pole span has a different vibration pattern. Conversely, it can be determined that the boundary area of the vibration pattern in FIG. 4 is the utility pole position.
  • FIGS. 5, 6, and 7 show examples of optical fiber vibration distribution patterns in which the amount of strain with respect to the optical fiber distance within the utility pole span measured by the DAS is sequentially accumulated for each time.
  • An overhead optical fiber cable can be regarded as a string that vibrates for each utility pole span, and by measuring the vibration pattern, it is possible to estimate the laying state of the optical fiber cable.
  • Fig. 5 shows the vibration pattern when the optical fiber cable is normal.
  • the wind-induced vibration propagates along the overhead fiber optic cable and within the utility pole span over time, where the amplitude of the vibration is uniform within the utility pole span.
  • Fig. 6 shows the vibration pattern when there is a load due to the attached matter on the optical fiber cable.
  • wind-generated vibrations propagate along the overhead fiber optic cable and within the utility pole span over time.
  • the amplitude of vibration is large at the load point of the deposit. That is, it can be seen that the amplitude of vibration is not uniform within the utility pole span.
  • Fig. 7 shows the vibration pattern when an obstacle on the ground, such as a tree, is in contact with the optical fiber cable. It can be seen from FIG. 7 that the wind-generated vibration propagates between the utility pole and the ground obstacle, but the vibration stops or reduces at the ground obstacle. That is, the vibration stops or reduces partway through the pole span and does not propagate along the fiber optic cable.
  • FIG. 8 shows a flow chart for judging whether the optical fiber cable is normal or abnormal.
  • DAS Distributed Acoustic Sensor
  • the optical fiber cable is normal (S15 ).
  • Vibration propagates along the overhead optical fiber cable within the utility pole span (Yes in S13), and when the amplitude of the vibration is not uniform within the utility pole span (No in S14), the optical fiber cable is loaded with deposits. (S16). Furthermore, it is possible to specify that there is a deposit at the point of discontinuity in the vibration amplitude.
  • the optical fiber cable When the vibration propagates between the utility pole and the ground obstacle, but stops or shrinks in the middle of the utility pole span and does not propagate along the optical fiber cable (No in S13), the optical fiber cable is on the ground. It is estimated that it is in contact with an obstacle (S17). Furthermore, it can be determined that the fiber optic cable is in contact with the ground obstacle at the point of vibration stoppage or reduction.
  • the position of the utility pole can be remotely specified, It is possible to estimate the state of the overhead optical fiber cable and identify the location of the fault.
  • DAS Distributed Acoustic Sensor
  • This disclosure can be applied to the information and communications industry.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Length Measuring Devices By Optical Means (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
  • Locating Faults (AREA)
PCT/JP2021/005852 2021-02-17 2021-02-17 電柱位置特定方法及び架空光ファイバケーブルの状態推定方法 Ceased WO2022176047A1 (ja)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP2023500173A JP7491458B2 (ja) 2021-02-17 2021-02-17 電柱位置特定方法及び架空光ファイバケーブルの状態推定方法
PCT/JP2021/005852 WO2022176047A1 (ja) 2021-02-17 2021-02-17 電柱位置特定方法及び架空光ファイバケーブルの状態推定方法
EP21926487.6A EP4296633A4 (en) 2021-02-17 2021-02-17 METHOD FOR DETERMINING THE POSITION OF A SUPPLY MAST AND METHOD FOR ESTIMATING THE CONDITION OF AN AIR FIBER OPTIC CABLE
CN202180093496.XA CN116917703A (zh) 2021-02-17 2021-02-17 电线杆位置确定方法和架空光缆的状态推定方法
US18/275,726 US12553769B2 (en) 2021-02-17 2021-02-17 Positioning method of electric pole and estimating method of the state of overhead optical fiber cable

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PCT/JP2021/005852 WO2022176047A1 (ja) 2021-02-17 2021-02-17 電柱位置特定方法及び架空光ファイバケーブルの状態推定方法

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024057492A1 (ja) * 2022-09-15 2024-03-21 日本電信電話株式会社 振動分布波形から電柱位置を特定する方法
WO2024166295A1 (ja) * 2023-02-09 2024-08-15 日本電信電話株式会社 設備位置解析装置及び設備位置解析方法
WO2025238718A1 (ja) * 2024-05-14 2025-11-20 Ｎｔｔ株式会社 信号処理装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11881688B2 (en) * 2021-04-12 2024-01-23 Nec Corporation Dynamic anomaly localization of utility pole wires

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190284931A1 (en) * 2018-03-13 2019-09-19 Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ Method and system for monitoring a material and/or a device in a bore hole using a fiber optic measuring cable
WO2020044660A1 (ja) * 2018-08-30 2020-03-05 日本電気株式会社 状態特定システム、状態特定装置、状態特定方法、及び非一時的なコンピュータ可読媒体
WO2020044648A1 (ja) * 2018-08-30 2020-03-05 日本電気株式会社 電柱位置特定システム、電柱位置特定装置、電柱位置特定方法、及び非一時的なコンピュータ可読媒体
CN111442788A (zh) * 2020-04-03 2020-07-24 南京晓庄学院 一种架空输电线路健康监测方法及系统
CN211234916U (zh) * 2019-12-17 2020-08-11 国网新疆电力有限公司昌吉供电公司 一种基于das与otdr的光缆状态监测系统
JP2020134142A (ja) * 2019-02-12 2020-08-31 日本電信電話株式会社 架空光ファイバケーブル検査方法、架空光ファイバケーブル検査装置及びプログラム
US20200370950A1 (en) * 2019-05-22 2020-11-26 Nec Laboratories America, Inc Rayleigh fading mitigation via short pulse coherent distributed acoustic sensing with multi-location beating-term combination

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2956842C (en) * 2016-02-04 2025-09-16 Ampacimon S.A. METHOD AND SYSTEM FOR MEASURING/DETECTING ATMOSPHERIC ACCRETION OF ICE OR SNOW ON OVERHEAD ELECTRICITY TRANSMISSION LINES
CN107727227B (zh) 2017-09-30 2019-05-21 南京大学 基于φ-otdr的高压输电线路覆冰舞动监测方法
WO2019126020A1 (en) * 2017-12-18 2019-06-27 The Curators Of The University Of Missouri Real-time overhead power line sag monitoring
JPWO2020044655A1 (ja) * 2018-08-30 2021-09-24 日本電気株式会社 電柱劣化検出システム、電柱劣化検出装置、電柱劣化検出方法、及びプログラム
CN109297662B (zh) * 2018-10-11 2024-04-12 三峡大学 一种架空电缆振动试验装置及试验方法
US11428570B2 (en) * 2019-04-05 2022-08-30 Nec Corporation Aerial fiber optic cable localization by distributed acoustic sensing
CN111238627B (zh) * 2020-01-20 2022-03-15 南京法艾博光电科技有限公司 一种架空输电线路中耐张塔的地理信息标定方法
US20230024381A1 (en) * 2020-01-22 2023-01-26 Nec Corporation Utility pole degradation detection system, utility pole degradation detection method, and utility pole degradation detection device
US20210318166A1 (en) * 2020-04-14 2021-10-14 Nec Laboratories America, Inc. Continuous aerial cable monitoring using distributed acoustic sensing (das) and operational modal analysis (oma)
US12467822B2 (en) * 2020-08-31 2025-11-11 Nec Corporation Utility pole deterioration discrimination device and method
WO2022113164A1 (ja) * 2020-11-24 2022-06-02 日本電気株式会社 光ファイバセンシングシステム、光ファイバセンシング方法、及び光ファイバセンシング装置
JP7444289B2 (ja) * 2020-11-27 2024-03-06 日本電気株式会社 位置特定システム、振動発生器、及び位置特定方法
JP7491464B2 (ja) * 2021-03-29 2024-05-28 日本電気株式会社 空間センシング装置、空間センシングシステム及び空間センシング方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190284931A1 (en) * 2018-03-13 2019-09-19 Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ Method and system for monitoring a material and/or a device in a bore hole using a fiber optic measuring cable
WO2020044660A1 (ja) * 2018-08-30 2020-03-05 日本電気株式会社 状態特定システム、状態特定装置、状態特定方法、及び非一時的なコンピュータ可読媒体
WO2020044648A1 (ja) * 2018-08-30 2020-03-05 日本電気株式会社 電柱位置特定システム、電柱位置特定装置、電柱位置特定方法、及び非一時的なコンピュータ可読媒体
JP2020134142A (ja) * 2019-02-12 2020-08-31 日本電信電話株式会社 架空光ファイバケーブル検査方法、架空光ファイバケーブル検査装置及びプログラム
US20200370950A1 (en) * 2019-05-22 2020-11-26 Nec Laboratories America, Inc Rayleigh fading mitigation via short pulse coherent distributed acoustic sensing with multi-location beating-term combination
CN211234916U (zh) * 2019-12-17 2020-08-11 国网新疆电力有限公司昌吉供电公司 一种基于das与otdr的光缆状态监测系统
CN111442788A (zh) * 2020-04-03 2020-07-24 南京晓庄学院 一种架空输电线路健康监测方法及系统

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
DAISUKE IIDA ET AL., IEICE GENERAL CONFERENCE, 2019, pages B-13 - 10
See also references of EP4296633A4
TIEJUN J. XIA ET AL., PROC OFC2020

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024057492A1 (ja) * 2022-09-15 2024-03-21 日本電信電話株式会社 振動分布波形から電柱位置を特定する方法
WO2024166295A1 (ja) * 2023-02-09 2024-08-15 日本電信電話株式会社 設備位置解析装置及び設備位置解析方法
WO2025238718A1 (ja) * 2024-05-14 2025-11-20 Ｎｔｔ株式会社 信号処理装置

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US12553769B2 (en) 2026-02-17
EP4296633A1 (en) 2023-12-27
CN116917703A (zh) 2023-10-20
EP4296633A4 (en) 2025-01-01
JPWO2022176047A1 (https=) 2022-08-25
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