Fiber-optic gyroscope having angular velocity correction
AssigneesHitachi Cable, Ltd., Hitachi, Ltd.
InventorsTatsuya Kumagai, Hiroshi Kajioka, Hisao Sonobe
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Abstract
The light emitted from a laser diode is divided into two lights and the divided lights are introduced into a sensing loop such that the lights propagate through the sensing loop clockwise and counterclockwise. These lights are combined by a light receiving device and then a signal processing circuit calculates an angular velocity .OMEGA.'. The temperature near the laser diode is detected to obtain a correction value Kt, a current supplied to the laser diode is detected to obtain a correction value Ki and a corrected angular velocity .OMEGA. is obtained by calculating the product of the angular velocity with the correction values Ki and Kt, i.e., .OMEGA.=.OMEGA.'*Ki*Kt.
Claims13
A fiber-optic gyroscope comprising:
- a sensing loop;
- means for dividing a light emitted from a light source into two lights;
- means for introducing the divided lights into the sensing loop, the lights propagating through the sensing loop clockwise and counterclockwise;
- means for comparing the lights exiting from the sensing loop to obtain a phase difference between the lights using the phase difference;
- means for calculating an angular velocity using the phase difference;
- means for detecting a temperature near the light source to obtain a first correction value to the temperature;
- means for detecting a current supplied to the light source to obtain a second correction value to the current;
- and
- means for obtaining a corrected angular velocity using a product of the first correction value, the second correction value and the angular velocity.
Dependencies are inferred from the claim text.