Optical fiber peg-top transition time on-line precise measuring method

Abstract

The invention discloses an online precision measurement method for the transit time of an optical fiber gyroscope. Use a phase modulator to perform square wave phase modulation on the system. The amplitude of the modulated square wave is not equal to an integer multiple of half the half-wave voltage of the phase modulator, and the period is greater than twice the estimated value of the transit time of the fiber optic gyroscope under test; use an analog-to-digital converter The output signal under square wave modulation is subjected to analog-to-digital conversion, and the digital level value of the corresponding sampling point is obtained by sampling. The results of multiple sampling conversions form a sampling sequence; the sampling sequence is binarized and filtered to obtain the output signal corresponding to the fiber optic gyroscope. The sequence of binarized filtering results is combined with the modulation square wave period to accurately obtain the transit time of the fiber optic gyroscope through numerical calculation. The present invention effectively and accurately measures the transit time of the fiber optic gyroscope online; provides a basis for the system to accurately select the period of the modulation signal, eliminates the zero bias caused by the transit time offset, suppresses various noise sources, and reduces the long-term drift of the fiber optic gyroscope. Improved static accuracy and resolution.

Description

technical field [0001] The invention relates to a signal processing method in an optical fiber gyroscope sensor, in particular to an online precision measurement method for the transit time of an optical fiber gyroscope. Background technique [0002] The transit time of the fiber optic gyroscope is the time required for light to propagate in the reciprocal optical path of the fiber optic gyroscope for one week, and its reciprocal is called the characteristic frequency of the fiber optic gyroscope, and the transit time can also be called the characteristic period of the fiber optic gyroscope. [0003] Medium and high-precision fiber optic gyroscopes adopt a digital closed-loop solution, which modulates the system through a phase modulator, and converts the signal of the fiber optic gyroscope into digital quantities through an analog-to-digital converter, and performs modulation and demodulation processing through a controller. The phase modulator plays two roles: it performs ...

AI Technical Summary

Problems solved by technology

[0006] The suppression effect of phase modulation on noise and drift is a complex subtractive function relationship with the error of the half cycle and transit time of the modulated signal. As the error increases, the suppression effect becomes worse and worse. When the error reaches a certain length The inhibitory effect basically disappears when

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