All digital DSP based closed-loop fiber optic gyroscope

The all digital close-loop fiber optic gyroscope (FOG) using digital signal processor (DSP) technique was presented. The multifunctional integrated optic circuit (MIOC) with square wave as biasing modulation and digital phase ramp as feedback was used. The designs of signal detector, digital demodulator, preamplifier and digital filter were discussed, and the theoretical and experimental test on the performance and parameters of the FOG were performed. The trade-off between the system precision and response time using DSP was also discussed. Test results have shown that the bias of the FOG is less than 0.3 (°)/h, and the scale factor nonlinearity of the FOG is less than 10^-4.