APPARATUS AND METHOD FOR ESTIMATING LOCATION OF VIBRATION IN OPTICAL FIBERING INTERFEROMETER TYPE VIBRATION DETECTING SENSOR

• Main Authors: NIKAIDO SHINICHI, FUKUDA TSUNEHIRO, OMORI TATSUYA, YAMAGUCHI MASATSUNE, TAKASHIMA TORU, YAMADA MASANORI, HASHIMOTO KIYONARI, OSAWA NORITAKA
• Format: Patent
• Language: English
• Published: 05.09.2003
• Edition: 7
• Subjects: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide an apparatus and a method for estimating the location of vibration in an optical fibering interferometer type vibration detecting sensor capable of detecting the location of a point of the addition of the vibration even in the case that the vibration is impressed at a midpoint in an optical fiber. SOLUTION: A light signal emergent from a light emitting element 1 is branched and made to be emergent onto both ends of the loop-shaped optical fiber 3. Each propagating light propagated clockwise and counterclockwise in the optical fiber 3 is made to be incident onto and coupled by a branching and coupling element 2. The propagating light from the branching and coupling element 2 is made to be incident on and converted into an electric signal by a light receiving element 5. The electric signal is converted into digitized time response data by an A/D converter 27. Fourier conversion is performed on the time response data to compute power spectral data. The frequency of a dip point contained in the power spectral data is retrieved. On the basis of the frequency of the dip point, the distance to the point of the addition of the vibration at which the optical fiber 3 is vibrated at the midpoint is identified. COPYRIGHT: (C)2003,JPO