Signal demodulation method of a frequency output resonant gyroscope is studied in this study. It has been a major problem of frequency micro gyroscopes. The detection elements of frequency gyroscopes are two double-ended tuning forks (DETF). The vibratory response of DETF is a periodic signal modulated by both amplitude and frequency. According to the characteristic that the amplitude and frequency of the gyro signal vary continuously with time, the signal demodulation algorithm is designed based on instantaneous frequency analysis. Hilbert transform is used to solve the instantaneous frequency. The algorithm is programmed in digital signal processor (DSP) and a test circuit board is made. Experimental test demonstrates that the demodulation circuit has a high precision and linearity, and the correlation coefficient between input signals and demodulation results achieves as much as 0.99999998. The demodulation method is proved to be feasible. This study provides a new train of thought for the study of the signal demodulation method of frequency micro gyroscopes and brings a new direction for the signal analysis of resonant sensors.

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Signal demodulation research of a frequency output resonant gyroscope based on instantaneous frequency analysis

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