Method and system for testing nonlinearity degree of closed-loop feedback circuit of fiber-optic gyroscope

Abstract

The invention provides a method and a system for testing the nonlinearity degree of a closed-loop feedback circuit of a fiber-optic gyroscope. The method comprises the steps that a digital signal processing chip generates a modulation voltage signal, and the modulation voltage signal is output to a Y waveguide phase modulator through a digital-to-analog converter and a modulation wave driving circuit, wherein the modulation voltage signal is a superposed signal of a nonlinear excitation modulation wave signal and a fixed step wave signal; the Y waveguide phase modulator is used for convertingthe modulation voltage signal into a modulation phase signal to obtain a modulation phase difference; a photoelectric detector detects the modulation phase difference, and the modulation phase difference is output to the digital signal processing chip through a preamplifier and an analog-to-digital converter; the digital signal processing chip calculates and outputs a first demodulation value according to the modulation phase difference; and a determination module determines the nonlinear degree of a modulation coefficient of the closed-loop feedback circuit according to the first demodulationvalue. The closed-loop test of the fiber-optic gyroscope is realized, so that the accuracy of the nonlinearity test of the feedback circuit is improved.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a method and system for testing the nonlinearity of a fiber optic gyroscope closed-loop feedback loop. Background technique [0002] As an inertial angular velocity sensor based on the Sagnac effect, the fiber optic gyroscope is widely used in the field of inertial measurement due to its unique technical and performance advantages. [0003] At present, fiber optic gyroscopes generally adopt closed-loop feedback methods to improve their sensitivity, stability, dynamic range and linearity of scale factors. The feedback loop includes three key components: a digital-to-analog converter (DAC), a modulating wave driver circuit (op amp), and an integrated optical modulator (Y-waveguide phase modulator). The DAC converts the digital signal into an analog current signal, and converts it into a voltage signal through a modulated wave drive circuit. The output of the drive circuit i...

AI Technical Summary

Problems solved by technology

[0009] Embodiments of the present invention provide a method and system for testing the nonlinearity of the fiber optic gyroscope closed-loop feedback loop to solve the problem of the accuracy of the fiber optic gyroscope feedback loop nonlinearity test

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