Analysis And Acquisition Of Photoelectric Signal In FOG

Fiber optic gyroscope (FOG) is a kind of optic interferometer, the function of which is to measure carrier's angle-velocity. The method of FOG to detect outer angle-velocity is by capture slender photoelectric signals, so, the characters of fiber and optic signal, and the influence of fiber's character in optic signals have great effect on FOG's performance.This paper has researched the character of fiber and the feature of light-wave in fiber by using polarization theory and reciprocity theory, at the same time, this paper analyzed optic interference theory in FOG and seek for the error reason in FOG, which have great meaning to increase FOG's precision and stability.Light source is the root for FOG, the stability of light-wave's power and average wavelength has direct effect on scale factor's consistency and FOG's whole performance. This paper analyzed the effect of light source's character on FOG, and the control circuit of light source. Electrooptic phase modulator is critical part in digital closed-loop FOG system, the function of which is to create bias phase, so that to make FOG working around zero point. Y wave-guide includes Y embranchments and mode polarization, its' performance indexes have great effect on FOG. This paper has analysis and experimental research on Y wave-guide.As we all know, temperature is great problem in fiber sensor fields, as well FOG. To decrease the effect of temperature on fiber coil, we adopted the technology and method of quadrupolar winding, and we have finished several fiber coils. This paper accomplished analysis of fiber coils and researched the effect of temperature on fiber coil.The processing and time-order controlling of optic interference signals are critical in fiber optic gyroscope system, they are cores in system designing. This paper analyzes the method of data processing , the sampling time-order of A/D converting and the method of sampling and transforming of high-speed data,which are based on the technology of FPGA, mainly aims at the principle of FOG and the characters of interference signals and A/D converting device. In the end, this paper builds closed-loop controlling plot, deduces transferring function, probes into stability of FOG's closed-loop feedback system, and analyzes the characters of digital feedback system.