Double-shaft multiplexing optical fiber gyro and signal modulation/demodulation method thereof

Abstract

The invention discloses a double-shaft multiplexing optical fiber gyro and a signal modulation / demodulation method thereof; two optical fiber rings which have 1:3 of optical fiber length and have mutually-vertical sensitive shafts are used on hardware configuration for carrying out parallel multiplexing by an optical fiber coupler; in the signal modulation / demodulation method, a square wave modulating signal is adopted to demodulate, the cycle of the square wave modulating signal is equal to the accumulated value of light transmission time in the two optical fiber rings, the duty ratio s 50 percent, the peak-to-peak value is not equal to the voltage value of multiple half-wave voltages, and the mean value is zero; in the cycle of the square wave modulating signal, the output signal of the optical fiber gyro is divided into four parts with equal length according to time sequence, and the signal in each part is sampled, according to the demodulation formula, the sampling values are calculated, so as to obtain angular velocity information with two different directions. The method can effectively reduce the equivalent cost of the double-shaft multiplexing optical fiber gyro and has high application value and popularization value.

Description

technical field [0001] The invention relates to a fiber optic gyroscope and a signal modulation and demodulation method thereof, in particular to a dual-axis multiplexing fiber optic gyroscope and a signal modulation and demodulation method thereof. Background technique [0002] Fiber optic gyroscope is a new type of angular velocity measuring instrument. It is widely used in navigation and attitude control systems due to its advantages of all solid state, wide bandwidth and digital output with multiple protocols. The working principle of the fiber optic gyro is a fiber optic interferometer based on the optical Segneck effect, that is, when the ring interferometer rotates, a Segneck phase difference proportional to the rotation angular rate is generated. By detecting the phase difference, it can be calculated The angular rate of the system in which the ring interferometer is located. Segneck phase shift φ Sag The relationship with the system angular rate Ω is as follows: ...

AI Technical Summary

Problems solved by technology

[0006] The cost of the whole system can be reduced through the method of multiplexing technology. The typical multiplexing method is to use the configuration method of light source multiplexing. This method only needs to use one light source for a multi-axis gyroscope, and add several fiber couplers. Yes, but this method can only reduce the cost of the light source. It still needs to use multiple different modulation channels and sampling channels, and the phase modulators, photodetectors, digital-to-analog conversion circuits and analogue circuits used in these two channels The digital conversion circuit occupies most of the cost of the entire fiber optic gyro system, and this part cannot be reduced; thus, the scheme of multiplexing the light source cannot effectively reduce the effective cost of the system, and other new multiplexing technologies are needed to effectively reduce its cost. Application cost, promoting the wide application of fiber optic gyroscope

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