Fujitsu Corporation

Fujitus Limited

Kazushi Uno

Takeo Kasajima

Fumio Takei

Hiroyasu Yoshikawa

Yasumasa Iwamura

Yuzuru Yamakage

Takahiro Arioka

Kouichi Tezuka

Hiroyuki Fukuda

Koichi Tezuka

Kyoko Tadaki

Minoru Ishinabe

Shingo Hamaguchi

Akiyoshi Uchida

Satoshi Shimokawa

Goro Kawasaki

Tsuyoshi Matsumoto

Tohru Fujimaki

Satoshi Itami

Kyoko Miyabe

Nobuyuki Kanto

Akihiro Itakura

Haruhiko Izumi

Toshikazu Kanaoka

Kiyoto Matsui

Takahiro Kashikawa

Akihiko Makita

Yoichi Takasu

Kyouko Tadaki

A computer-readable, non-transitory medium storing a program that causes a computer to execute a process is provided. The process includes acquiring a backward Rayleigh scattered light from an optical fiber composite overhead ground wire of an electrical power transmission facility; generating vibration information of a frequency band including a natural frequency of the optical fiber composite overhead ground wire, on a basis of the backward Rayleigh scattered light; and detecting abnormality of the electrical power transmission facility, on a basis of the vibration information.

Computer-readable non-transitory medium, abnormality detection device and abnormality detection method

A determination device includes: a memory; and a processor coupled to the memory and the processor configured to executes a process, the process comprising: generating a reference model of a sensor detection value; determining whether a time from a predetermined point in time until a deviation between the reference model and the sensor detection value exceeds a threshold is shorter than a predetermined time; and outputting a signal associated with an abnormality when the time is determined to be shorter.

Determination device, determination method, and non-transitory computer-readable recording medium

A temperature measurement device includes: a light source configured to input a light into an optical fiber; a detector configured to detect a Stokes component and an anti-Stokes component from a back scattering light from the optical fiber; a memory; and a processor configured to execute a process, the process comprising: in a predetermined region including a sample point of the optical fiber, calculating a range including the sample point in accordance with a largeness of a correlation between the Stokes component and the anti-Stokes component; smoothing the Stokes component and the anti-Stokes component in the range; and measuring a temperature of the sample point with use of the Stokes component and the anti-Stokes component that are smoothed by the corrector.

Temperature measurement device, temperature measurement method, and computer-readable non-transitory medium

A temperature measurement device includes: a detector to detect first Stokes and anti-Stokes components when a light is input into a first end of an optical fiber and detect second Stokes and anti-Stokes components when a light is input into a second end; and a processor to execute a process including: calculating a first section from a first correlation between the second Stokes component and at least one of the first Stokes and the first anti-Stokes components, calculating a second section from a second correlation between the second anti-Stokes component and at least one of the first Stokes and the first anti-Stokes components, smoothing the second Stokes component in the first section, smoothing the second anti-Stokes component in the second section; and measuring a temperature by using the second Stokes and the second anti-Stokes components after smoothing, the first Stokes component and the second Stokes component.

A temperature measurement device includes: a detector to detect a first Stokes component and a first anti-Stokes component when a light is input into a first end of an optical fiber and detect a second Stokes component and a second anti-Stokes component when a light is input into a second end; and a processor configured to execute a process comprising: replacing the second anti-Stokes component with a value according to the first Stokes component, the first anti-Stokes component and the second Stokes component when any one of correlations of the second anti-Stokes component to the first Stokes component and the first anti-Stokes component is less than or equal to a threshold value; and measuring a temperature at the sample point by using the first Stokes component, the first anti-Stokes component, the second Stokes component, and the second anti-Stokes component that is replaced in the replacing.

An optical fiber cord includes: an optical fiber; and a cover material covering the optical fiber, the cover material being formed by braiding a plurality of yarns. Moreover, an abnormality detection system includes: the optical fiber covered with the cover material formed by braiding the plurality of yarns; a scattered light detector configured to detect scattered light occurring in the optical fiber and output data on intensity distribution in a longitudinal direction of the optical fiber; and a data processor configured to determine the presence or absence of an abnormality based on the data outputted from the scattered light detector.

Optical fiber cord and abnormality detection system

A temperature measuring system includes a laser light source to emit optical pulses, an optical fiber, arranged to pass through a plurality of measuring points, and input with the optical pulses, and a measuring device to detect back-scattering light output from the optical fiber and measure a temperature at the plurality of measuring points, to acquire measured temperature data. The measuring device computes corrected temperature data by varying a degree of smoothing the measured temperature data in a distance direction of the optical fiber, according to a correlation between the measured temperature data and a transfer function peculiar to the temperature measuring system.

Temperature measuring system and temperature measuring method

A temperature measuring system includes a laser light source that emits optical pulses, an optical fiber, arranged to pass through a plurality of temperature measuring points, and input with the optical pulses, and a measuring device that detects back-scattering light output from the optical fiber and measures a temperature at the plurality of measuring points, to acquire measured temperature data. The measuring device computes corrected temperature data by varying a degree of averaging of the measured temperature data in a time direction, according to whether a time-sequential difference temperature data have a spatial correlation or a time correlation within a range that uses a target position of the optical fiber as a reference.

A temperature measurement device includes: an optical fiber that is arranged along a predetermined path; a light source configured to input a light into the optical fiber; a measurer configured to measure temperature distribution information in an extension direction of the optical fiber based on a back-scattering light from the optical fiber; and a corrector configured to make a filter for reducing a noise component of temperature distribution information measured by the measurer based on a difference of temperature distribution information between two different regions of the optical fiber in which a common temperature distribution is obtained, and correct the temperature distribution information by applying the filter to the temperature distribution information.

Temperature measurement device and temperature measurement method

An abnormality detection system includes an optical fiber, a backscattered light detector, and a data processor. The backscattered light detector is connected to one end side and the other end side of the optical fiber, and configured to acquire a first intensity distribution of backscattered light by making light incident on the optical fiber from the one end side and to acquire a second intensity distribution of backscattered light by making light incident on the optical fiber from the other end side. The data processor calculates transmission loss at each position in the longitudinal direction of the optical fiber by using the first and second intensity distributions and a normalization function, and determines whether or not there is an abnormality based on the result of the calculation.

Abnormality detection system and abnormality detection method

An abnormality detection system includes an optical fiber, a Raman scattered light detection unit, and a data processing unit. The detection unit is configured to detect Stokes light and anti-Stokes light which are generated in the optical fiber and to output data on the intensity distribution of the Stokes light in the optical fiber in the length direction thereof and data on the intensity distribution of the anti-Stokes light in the optical fiber in the length direction. The processing unit is configured to calculate the product of a value obtained by applying an FIR filter to the intensity distribution of the Stokes light, and a value obtained by applying the FIR filter to the intensity distribution of the anti-Stokes light for each of locations on the optical fiber in the length direction, and to determine whether or not abnormality is present based on the result of the calculation.

A temperature measurement system includes an optical fiber, a temperature distribution measurement apparatus, and a data processing apparatus. The temperature distribution measurement apparatus is configured to detect backscattered light by causing light to enter the optical fiber, and acquire the temperature distribution of the optical fiber in the length direction thereof based on the result of the detection. The data processing apparatus is configured to store therein the temperature distribution acquired by the temperature distribution measurement apparatus, perform signal processing on a difference temperature distribution obtained by computing the difference between a current temperature distribution and a past temperature distribution, and determine whether or not abnormality is present based on the result of the signal processing.

Temperature measurement system and abnormality detection method

A temperature distribution measurement apparatus includes a laser light source optically connected to an optical fiber, a photodetector configured to detect light backscattered in the optical fiber, and a temperature distribution measurement unit configured to obtain a true measured temperature distribution by performing correction calculation using a transfer function on a temporary measured temperature distribution obtained based on an output from the photodetector. The temperature distribution measurement unit stores therein data on a transfer function set for each entire length of the optical fiber and for each longitudinal position in the optical fiber. Then, when the length of the optical fiber is changed, the temperature distribution measurement unit changes the transfer function to be used in the correction calculation by using the data on the transfer function.

Temperature distribution measurement apparatus and temperature distribution measurement method

An abnormality detection system includes an optical fiber, a backscattered light detection unit, and a data processing unit. The detection unit is connected to one end and the other end of the optical fiber and configured to acquire a first intensity distribution of backscattered light by causing light to enter the optical fiber from the one end, and to acquire a second intensity distribution of backscattered light by causing light to enter the optical fiber from the other end. The processing unit is configured to calculate the product of a value obtained by applying a first FIR filter to the first intensity distribution, and a value obtained by applying a second FIR filter to the second intensity distribution, for each of locations on the optical fiber in the length direction thereof, and to determine whether or not abnormality is present based on the result of the calculation.

A temperature distribution measurement system includes an optical fiber, a laser light source optically connected to the optical fiber, a photodetector configured to detect light backscattered in the optical fiber, and a temperature distribution measurement unit configured to perform correction calculation using a transfer function on a measured temperature distribution obtained from an output from the photodetector. The temperature distribution measurement unit acquires an actual temperature distribution in a location where the optical fiber is laid and determines appropriateness of the transfer function by computing a difference between the measured temperature distribution after the correction and the actual temperature distribution.

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Kawasaki, Japan

Kazushi Uno