The Research On Signal Processing Of All-digital Closed-loop Interferometric Fiber-optic Gyroscope

The interferometric fiber-optic gyroscope (IFOG) attracts considerable researchers because of its distinguishing performance. In our country, fiber-optic gyroscope is looked as one of key technology in the domain of inertial navigation. The scale factor linearity and stability of the IFOG must be improved in order to apply IFOG to high-precision case. The development of optic-electric apparatus. performance and advancement of digital processing technology provide material foundation and technological support for high-precision IFOG.The paper analyzes the principle of IFOG. From the performance of IFOG' scale factor, the signal detecting scheme of IFOG is analyzed. A signal processing scheme of all-digital closed-loop IFOG is best for high grate IFOG system.For the high grate IFOG, all digital processing scheme of closed-loop IFOG is proposed. In this scheme , digital demodulator is used to detect IFOG' error signal, square wave is used to biase, digital phase ramp modulator is used as feedback controlling and digital filter is used to limit noise, lower the bit and eliminate dead band error of A/D, D/A. These methods are studied and prove true.At the same time , the paper analyzes these factors that bright about non reciprocal phase drift of IFOG and points out eliminating approaches, analyzes digital demodulator retraining the noise, analyzes drift of digital phase ramp peak . Especially in the case of angle acceleration , the paper presents opinion on how affect on signal processing of IFOG the optical source' s fluctuating . These are meaningful to the research and development of high-precision IFOG.