Collaborative Force Rebalance Strategy for Enhanced Dynamic Range and Resolution in MEMS Gyroscopes

Although the force rebalance (FRB) solves the bandwidth expansion problem of MEMS gyroscopes with mode matching, it faces a tradeoff between high resolution and large range. To solve this issue, this article proposes a collaborative FRB (CFRB) strategy for MEMS gyroscopes. The method uses a distribution algorithm to enable FRB electrodes with different capacitance parameters to work together, achieving both high resolution and large range. An eight-mass gyroscope (EMG) with feedback electrodes of varying electrostatic force efficiencies is designed to adapt the CFRB strategy. The influence of different feedback efficiencies on the output noise in FRB mode and the methods for noise reduction was analyzed. The feasibility of CFRB is verified through simulation. Experimental results demonstrate that the MEMS gyroscope achieves a resolution of 0.002°/s and a range of at least ±1000°/s with a scale factor nonlinearity of 106 ppm. Static testing in CFRB mode shows bias instability of 0.3°/h and angle random walk (ARW) of 0.1°/ $\surd $ h.