Signal demodulating method for inhibiting vibration error of fiber optic gyro

Abstract

The invention provides a signal demodulating method for inhibiting a vibration error of a fiber optic gyro. After a system is powered on, light power signals detected by a photoelectric detector in real time are subjected to filtration, amplification and an A / D converter to form digital signals; the digital signals are latched by a digital latch module; and the latched light power digital singles are demodulated to form Sagnac phase difference signals, 2pi voltage deviation signals and light power signals; the demodulated Sagnac phase difference signals are divided by the light power signals to obtain new demodulated signals which are amplified and output to a Sagnac phase deviation compensation modulation module; the demodulated 2pi voltage deviation signals are output to a 2pi voltage error compensation modulation module; and then the modulated signals of Sagnac phase deviation compensation signals and 2pi voltage error compensation modulation signals are fed back to a gyro closed loop. In the method, a constant drift error of the gyro and partial additional noise error caused by vibration are eliminated, and the measuring accuracy of the gyro in vibration environment is improved.

Description

(1) Technical field [0001] The invention relates to the field of optical fiber sensing in optoelectronic technology, in particular to a method for suppressing the vibration error of an interference type optical fiber gyroscope. More specifically, it is a method of eliminating measurement errors caused by vibrations through signal demodulation. (2) Background technology [0002] Fiber optic gyro is an instrument for measuring angular velocity, which is composed of light source 1, coupler 2, Y waveguide 3, fiber optic ring 4, photoelectric detector 5 and signal processing device 6 and other hardware. The signal processing device 6 includes a timing control module 60, filtering, amplification, A / D conversion module 61, digital signal demodulation module 62, Sagnac phase shift compensation modulation module 63, 2π voltage error compensation modulation module 64, D / A The conversion and amplification module 65, and the gyro signal output module 66, and the interference fiber opti...

AI Technical Summary

Problems solved by technology

Since the gyro is used to measure the attitude angle and angular velocity of the carrier, it needs to be fixed to the carrier, so the measurement results will be affected by the vibration of the carrier and cause errors

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