Ultrahigh-precision fiber optic gyroscope based on closed-loop phase locking method

Abstract

The invention discloses an ultrahigh-precision fiber optic gyroscope based on a closed-loop phase locking method. An optical signal obtained after a light source is modulated by a subcarrier modulatorunit and a subcarrier modulation light source unit carries a subcarrier at certain frequency and is coupled to a multi-circle fiber optic ring by a coupler, the fiber optic ring outputs the optical signal to an interferometer demodulation subcarrier unit connected with a phase-locked loop unit, and an interference local oscillator subcarrier signal is provided by another branch of the subcarriermodulator unit; the demodulated subcarrier frequency signal with the phase and frequency changed is input into a PLL circuit to serve as frequency of the phase-locked loop, compared with a PLL reference subcarrier VCO circuit in real time, then converted into a data signal by an A / D unit and input into a CPU unit for processing. The fiber optic gyroscope has ultrahigh stability, reproducibility, ultrahigh detail analyticity, has the highest precision up to 0.000001 degree / h and can keep ultrahigh resolution and sensitivity while keeping the ultrahigh precision.

Description

technical field [0001] The invention relates to a gyroscope, in particular to an ultra-high-precision fiber optic gyroscope based on a closed-loop phase-locking method. Background technique [0002] The principle of the gyroscope is that the direction of the rotation axis of a rotating object will not change when it is not affected by external forces. According to this principle, a gyroscope is manufactured with a mechanical structure and a detection circuit, and it is used to maintain the direction. It is mainly used to measure angular displacement and angular velocity. The inertial sensor is an important component of the inertial navigation system. [0003] The original products are mainly mechanical gyroscopes, while the latest fiber optic gyroscope is a new type of solid-state angular velocity inertial sensor developed based on the Sagnac effect. Compared with the traditional mechanical gyroscope, the fiber optic gyroscope has many advantages such as non-rotating fixed ...

AI Technical Summary

Problems solved by technology

If more precision is required, it cannot be achieved with existing technology

[0005] The inventors have found that the signal processing part, especially the pre-op amplifier part of the phase change information of the measured signal obtained based on the Sagnac effect, is the same or similar to the processing circuit used at home and abroad, due to temperature drift, external electromagnetic interference , device parameter drift and other factors will cause its accuracy, sensitivity, resolution, etc. to be limited, and the repeatability accuracy will be lower. In addition, there is a detection value of 0 when the optical fiber ring of the gyroscope rotates at a low speed. question

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