OPTICAL FIBER GYRO

• Main Authors: KAJIOKA HIROSHI, KUMAGAI TATSUYA, AKIYAMA MUNEHIRO
• Format: Patent
• Language: English
• Published: 23.04.1999
• Edition: 6
• Subjects: GYROSCOPIC INSTRUMENTS; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; NAVIGATION; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; SURVEYING; TESTING

PROBLEM TO BE SOLVED: To obtain an optical fiber gyro in which a measuring error due to a disturbance is suppressed with a simple configuration, by a method wherein a phase modulation signal which gives a phase difference in an opposite phase is generated with reference to a phase difference between clockwise light and a counterclockwise light generated due to the disturbance applied to an optical path. SOLUTION: Light from a light source 22 is branched in a light branching and synthesizing part 25 by an optical integrated circuit 24, it is incident on a sensing coil 26 in an optical path 1 as a beam of clockwise light and a beam of counterclockwise light, both beams of light are synthesized in the light branching and synthesizing part 25 so as to interfere mutually, and both beams of light are incident on a photodetector 31. A detection signal in the photodetector 31 is inputted to a gate array 40 via a preamplifier 32 and an A/D converter 34. A microcomputer 43 monitors a thermistor 41 and an accelerometer 42, it reads out information which offsets a phase difference so as to correspond to a disturbance detection value, it generates a phase modulation signal, and it superposes the phase modulation signal on staircases in the gate array 40. A signal which suppresses the phase difference is sine waves in an opposite phase. When they are superposed, it is possible to offset the phase difference between the clockwise light and the counterclockwise light due to a disturbance.