A random four-state modulation method for digital closed-loop fiber optic gyroscope

Abstract

The invention discloses a random four-state modulation method for a digital closed-loop fiber optic gyroscope, which includes: using a pseudo-random number generator to generate a pseudo-random number sequence, and establishing a multi-state modulation state memory and state transfer torque; constructing a random modulation state selector to select any A pseudo-random number, and select a modulation state from the multi-state modulation state memory; complete the state transition output according to the pseudo-random number and modulation state combined with the state transition matrix; establish a modulation state delayer, generate a random modulation four-state phase, based on random modulation The four-state phase combination generates a demodulation mark; the demodulation of the angular rate of the fiber optic gyroscope and the 2π voltage is completed by using the demodulation mark. The technical solution of the present invention aims at the problem of random drift and dead zone of the gyroscope caused by the electronic crosstalk between the modulation and demodulation signals of the digital closed-loop fiber optic gyroscope, and adopts the random four-state modulation method of the fiber optic gyroscope, which can improve the accuracy of the fiber optic gyroscope and ensure the working stability of the fiber optic gyroscope. greater practical significance.

Description

technical field [0001] The invention belongs to the field of fiber optic gyroscopes, and in particular relates to a random four-state modulation method for digital closed-loop fiber optic gyroscopes. Background technique [0002] The fiber optic gyroscope is an angular rate sensor based on the Sagnac effect. Due to its low cost, simple process, high reliability, and strong shock and vibration resistance, its application prospects have attracted much attention and it has become one of the mainstream sensors. Due to the electronic crosstalk error between the Y-waveguide phase modulation signal and the detector output signal, the current digital closed-loop fiber optic gyroscope causes random drift and dead zone phenomenon in the gyroscope. [0003] In the prior art, a random phase jump modulation method is mainly used to solve the problem of electronic crosstalk between modulation and demodulation signals of the digital closed-loop fiber optic gyroscope. Specifically, the ran...

AI Technical Summary

Problems solved by technology

Due to the limitation of memory space on fiber optic gyro products, this method will make the length of the pseudo-random sequence stored in the memory limited. The modulation phase has weak suppression of light source intensity and noise. Do not use high-precision gyro applications. The duration of each phase is τ and cannot perform real-time demodulation of 2π voltage. It affects the scale factor linearity index of the gyro at small angular velocities.

Therefore, the random modulation method has certain limitations

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