Dynamic characteristics test of fiber optic gyroscope based on cross-correlation identification

Dynamic characteristic is important to the fiber optic gyroscope, and it is difficult to test with traditional mechanical equipments. A method based on cross-correlation identification was proposed to realize the dynamic characteristic test. Considered the principle of digital closed-loop fiber optic gyroscopes which adopted the digital step feedback to realize closed-loop control, the method was designed by means of adding pseudo random binary signal (PRBS) to the feedback serrodyne. The PRBS was the identification input signal and the closed-loop output was the identification output signal. After the wavelet filtering, the closed-loop output was correlated with PRBS to get the impulse response, and then fast Fourier transform was used to get the amplitude-frequency and phase-frequency characteristics. The testing result of the cross-correlation identification is compared with that of the previous method and shows that they are basically consistent. The cross-correlation identification is effective, easy to realize, and more fit for practical engineering test.