A Thermal-Robust Bandwidth Expansion Method for MEMS Gyroscopes Based on Parameter Self-Adjustment

This article proposes a notch filter proportional-derivative controller (NF-PDC) for the closed-loop system of the MEMS ring gyroscopes within a wide temperature range. This study analyzes through Bode diagrams and theoretical formulations how the resonance frequency split and Q-factor collectively influence the mechanical bandwidth of gyroscopes. The NF-PDC is devised, and all controller parameters are adjusted in real time using the gyroscopes’ internal parameters (resonant frequencies and Q-factor). Using the controller in the closed-loop system, the bandwidth of the ring gyroscope is expanded, and the problem of the trade-off between the mechanical bandwidth and the mechanical sensitivity of the gyroscope is solved. Upon experimental validation, the bandwidth has been extended from 3 to 100 Hz. And the result of bandwidth expansion within the wide temperature range is satisfactory. The scale factor nonlinearity is optimized 10.9 times. Bias instability (BI) and angular random walk (ARW) are optimized 10.1 times and 6.4 times, respectively. The proposed method can be applied to the performance optimization of gyroscopes.