Fiber optic gyroscope capable of eliminating influence of wavelength change to scale factor

Abstract

The invention discloses a fiber optic gyroscope capable of eliminating influence of wavelength change to a scale factor. A light source is divided from the middle into two light beams by passing a first fiber optic coupler and a phase modulator, and the two light beams return back to a first photoelectric detector after being transmitted in a fiber optic ring clockwise and counterclockwise; the light source reaches a first fiber optic grating after passing the first fiber optic coupler, a second fiber optic coupler, a third fiber optic coupler and a fourth fiber optic coupler, reaches a second fiber optic grating after passing the first fiber optic coupler, the second fiber optic coupler, the third fiber optic coupler and a fifth fiber optic coupler and reaches a third fiber optic grating after passing the first fiber optic coupler, the second fiber optic coupler and a sixth fiber optic coupler; three reflected lights with different wavelengths reaches a second photoelectric detector, a third photoelectric detector and a fourth photoelectric detector respectively by passing the fourth fiber optic coupler, the fifth fiber optic coupler and the sixth fiber optic coupler, so that an optical signal is converted into an electric signal; the real-time central wavelength of the light source is calculated and the scale factor of the fiber optic gyroscope is corrected in a central processing unit by a preamplifier and an A/D converter; and simultaneously, the central processing unit controls the phase modulator by a D/A converter and generates a modulation waveform and phase feedback so as to output a gyroscope signal. According to the invention, the requirement of the fiber optic gyroscope to an environment is lowered, and the application range of the fiber optic gyroscope is expanded.

Description

technical field [0001] The invention relates to an optical fiber gyroscope, in particular to an optical fiber gyroscope which eliminates the influence of wavelength variation on the scale factor. Background technique [0002] The fiber optic gyroscope is a sensor based on the Sagnac effect, which obtains angular velocity information by detecting the Sagnac phase shift caused by rotation. The light source of the fiber optic gyroscope often adopts a wide-spectrum light source, and the typical ones are semiconductor superfluorescent light source (SLD) and fiber optic light source (FLS). Among them, semiconductor superfluorescent light source is widely used in medium and low precision fiber optic gyroscopes because of its small size and low cost. [0003] Among the many key indicators of fiber optic gyroscope, the scale factor of fiber optic gyroscope is an indicator to measure the dynamic performance of fiber optic gyroscope. It includes two aspects of scale factor nonlinearit...

AI Technical Summary

Problems solved by technology

Due to the limited temperature control accuracy, although this method can improve the stability of the central wavelength of the light source, it still cannot meet the requirements of the scale factor within 10ppm, and the start-up time at high and low temperatures will also be limited; another method is the fiber optic gyroscope. Scale factor environmental characteristics are calibrated for software compensation

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