Random four-state modulation method of digital closed-loop fiber-optic gyroscope

Abstract

The invention discloses a random four-state modulation method of a digital closed-loop fiber-optic gyroscope. The random four-state modulation method of the digital closed-loop fiber-optic gyroscope comprises the steps that a pseudo-random number generator is utilized to generate a pseudo-random number sequence, and a multi-state modulation state memory and state transition moment are established;a random modulation state selector is constructed, a random pseudo-random number is selected, and a modulation state is selected from the multi-state modulation state memory; state transition outputis completed according to the pseudo-random number and the modulation state combined with a state transition matrix; a modulation state delayer is established, a random modulation four-state phase position is generated, and based on the random modulation four-state phase position, a demodulation mark is generated in a combined mode; and the demodulation of the fiber-optic gyroscope angular rate and 2 pi voltage is completed by using the demodulation mark. According to the technical scheme of the random four-state modulation method of the digital closed-loop fiber-optic gyroscope, aiming at theproblems of gyroscope random drift and dead zones caused by electronic crosstalk between modulation signals and demodulation signals of the digital closed-loop fiber-optic gyroscope, the random four-state modulation method of the digital closed-loop fiber-optic gyroscope is adopted, the precision of the fiber-optic gyroscope can be improved, the working stability of the fiber-optic gyroscope is ensured, and the random four-state modulation method of the digital closed-loop fiber-optic gyroscope has great 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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