On-line tracking method and system for eigenfrequency of fiber-optic gyroscope

Abstract

The invention discloses an on-line tracking method and system for eigenfrequency of a fiber-optic gyroscope. The fiber-optic gyroscope comprises an ASE light source, an optical fiber coupler, an integrated optical phase modulator and a light sensitive ring which are connected in sequence, the feedback end of the optical fiber coupler sequentially passes through the photoelectric detector, the pre-amplifier and the analog-to-digital converter and then is input to the signal receiving end of the logic processor, and the control end of the integrated optical phase modulator sequentially passes through the buffer amplifier and the digital-to-analog converter and then is connected to the signal sending end of the logic processor. The method comprises the following steps: constructing a modulation signal obtained by superposing a four-state square wave and a sawtooth wave, transmitting the modulation signal through a closed-loop control loop of the fiber-optic gyroscope to obtain a to-be-demodulated signal, demodulating an error between a modulation frequency and an actual frequency of the fiber-optic gyroscope, and dynamically adjusting a modulation frequency source clock of the fiber-optic gyroscope. Therefore, automatic tracking of the eigenfrequency of the fiber-optic gyroscope is realized, an angular velocity closed loop and a half-wave voltage closed loop are not influenced, and the precision of an angular velocity channel of the fiber-optic gyroscope is not influenced.

Description

technical field [0001] The invention belongs to the technical field of fiber optic gyroscopes, and more specifically relates to an online tracking method and system for the eigenfrequency of a fiber optic gyroscope. 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. High-precision fiber optic gyroscopes generally use four-state square wave overmodulation technology to bias the fiber optic gyroscope, and the four-state square wave modulation frequency is required to be consistent with the actual eigenfrequency of the fiber optic gyroscope. But in the existing fiber optic gyro, the modulation frequency is set according to the eigenfrequency measured at room temperature. [0003] During the temperature change process of...

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Problems solved by technology

[0004] Aiming at at least one defect or improvement requirement of the prior art, the present invention provides an online tracking method and system for the eigenfrequency of the fiber optic gyroscope, aiming to solve the problem that the traditional four-state square wave modulation method cannot track the actual eigenfrequency of the fiber optic gyroscope technical problem

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