Fiber-optic gyroscope modulation and demodulation method

Abstract

The invention discloses a fiber-optic gyroscope modulation and demodulation method. The method comprises the following steps: carrying out intrinsic square wave modulation on optical waves through Y waveguide by using a pi/2 + kpi modulation amplitude, wherein k is an integer; respectively sampling the optical power reaching a detector in the positive and negative half periods in every modulation period to obtain parity sampling values; obtaining a difference between the parity sampling values in the period according to the parity sampling values in every modulation period and the sum value of the parity sampling values in the period; and dividing the difference between the parity sampling values by the sum value of the parity sampling values, adopting the ratio as a demodulation signal, and resolving the demodulation signal to obtain the phase difference induced by fiber-optic ring rotation and rotating angle velocity information. The demodulation method can inhibit the gyroscope drift phenomenon caused by the optical power and optical path loss.

Description

technical field [0001] The invention relates to the technical field of fiber optic gyroscopes, in particular to a modulation and demodulation method for fiber optic gyroscopes. Background technique [0002] The fiber optic gyroscope is a sensitive element based on a fiber optic coil, and the light waves emitted by the light source propagate along the fiber in two directions. Compared with the traditional mechanical gyroscope, the fiber optic gyroscope has the advantages of all solid state, no rotating parts and friction parts, long life, large dynamic range, instant start, simple structure, small size and light weight. Compared with the laser gyroscope, the fiber optic gyroscope has no locking problem, and does not need to precisely process the optical path in the quartz block, so the cost is low. [0003] Foreign countries have studied fiber optic gyroscopes earlier, and their development and production levels are also relatively high. As early as the end of the last centu...

AI Technical Summary

Problems solved by technology

The solution period (2τ) of the fiber optic gyroscope is generally on the order of microseconds. In such a short period of time, the power of the light source and the optical path loss change very little and can be ignored. That is, the gyro data is normal in a single solution period, but as time goes , when the light source power change or the optical path loss change cannot be ignored, it will inevitably cause calculation errors and cause the zero position of the fiber optic gyroscope to drift

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