A Precision Closed-loop Driving Scheme of Silicon Micromachined Vibratory Gyroscope

This paper describes a precision closed-loop driving scheme for Silicon Micromachined Vibratory Gyroscope (SMVG). It decouples the angle and gain of the self-oscillation-driven, optimizes the angle to reduce the relative difference between drive frequency and resonant frequency of the drive mode and achieves the closed-loop self-oscillation-driven by nonlinear relation between DC voltage using for control and drive force. The experiments show that the standard deviation of drive frequency is 0.009Hz, with relative drift 2.2ppm and the standard deviation of the amplitude is 0.0025mV, with relative drift 15ppm in one hour respectively. The closed-loop drive scheme improves the precision and stability of drive frequency and the amplitude of the gyroscope well. The paper analyses and tests the noise of the self-oscillation-driven. The result shows that the self-oscillation-driven has a rms noise below -100dB.