An In-Run Automatic Mode-Matching Method With Amplitude Correction and Phase Compensation for MEMS Disk Resonator Gyroscope
Jingbo Ren, Tong Zhou, Yi Zhou, Yixuan Li, Yan Su
Abstract
To resolve the problem of frequency split arising from non-uniform circumferential stiffness distribution in the fully symmetrical resonator structure of Micro-Electro-Mechanical systems (MEMS) vibration gyroscopes due to processing errors. In this research, an in-run automatic mode-matching method with amplitude correction and phase compensation is proposed for a MEMS disk resonator gyroscope (DRG). A double-sideband signal negative feedback system is constructed with a double-sideband signal as the input and the sense mode output signal as the output. By comparing the response amplitude difference between the lower sideband signal and the upper sideband signal using the negative feedback system, the identification and measurement of the frequency split between gyroscope modes are realized. In addition, the deterioration of tuning accuracy due to the amplitude asymmetry and circuit phase errors are studied theoretically and by simulation. A response amplitude demodulation method with amplitude correction and phase compensation is proposed to further improve the tuning accuracy. The results of experiments show that the bias instability (BI) and the angle random walk (ARW) of the MEMS DRG are 0.5662 °/h and 0.03935 °/√h, respectively, when adopting the mode-matching method with compensation. Compared with the mode-matching method without compensation, the BI and the ARW of the MEMS DRG are increased by 3.07 and 1.62 times, respectively. The tuning accuracy is controlled within -0.06 Hz in the mode-matching state.