All Digital DSP Based Closed-Loop Fiber Optic Gyroscope

An all digital closed-loop fiber optic gyroscope (FOG) using digital signal processor (DSP) technique is presented.A multifunction integrated optic circuit (MIOC) is used, with square wave for biasing modulation and digital phase ramp for feed back. The design of signal detector,digital demodulator,preamplifier and digital filter is discussed, and theoretical analysis and experimental test on the performance and parameters of the closed-loop fiber optic gyroscope are performed.A trade-off between the system precision and response time using DSP is also discussed. Test results show that the bias of FOG is less than 0.3°/h, and the scale factor nonlinearity of FOG is less than 100×10⁶.