Title:
VIBRATION DETECTING OPTICAL FIBER SENSOR AND VIBRATION DETECTION METHOD
Document Type and Number:
Japanese Patent JP2020041972
Kind Code:
A
Abstract:
To utilize the nature of noise in addition to utilizing a moving average and moving difference, and thereby statically evaluate a change in OTDR waveform and clearly discriminate whether there is an abnormal vibration.SOLUTION: A light intensity acquisition unit acquires the intensity of output light derived from probe light when it is backscattered by an optical fiber. OTDR waveform acquisition means sequentially acquires an OTDR waveform that is transmitted from the light intensity acquisition unit and is the waveform of output light for each optical pulse, and stores it. Moving average acquisition means averages kth to k+M-1th OTDR waveforms that are contiguous in time, acquires a kth moving average waveform, and stores it. Difference waveform acquisition means acquires a difference waveform between the k+M+Nth OTDR waveform and the kth moving average waveform. Statistical information acquisition means acquires a sample average μ and a standard deviation σ of the difference waveform. Abnormality degree acquisition means calculates the degree of abnormality of each position and acquires an abnormality degree waveform that indicates the degree of abnormality. Abnormality determination means determines the presence of abnormal vibration from the value of degree of abnormality and, when abnormal vibration exists, acquires its position.SELECTED DRAWING: Figure 1
Inventors:
KANDA YOSHIHIRO
Application Number:
JP2018171438A
Publication Date:
March 19, 2020
Filing Date:
September 13, 2018
Export Citation:
Assignee:
OKI ELECTRIC IND CO LTD
International Classes:
G01H9/00; G01M99/00
Domestic Patent References:
| JP2017026503A | 2017-02-02 |
Foreign References:
| CN108088548A | 2018-05-29 | |||
| CN102865914A | 2013-01-09 |
Attorney, Agent or Firm:
Hiroyuki Okada
Takashi Ogaki
Takashi Ogaki