0.003°/h bias instability of honeycomb disk resonator gyroscope achieved by mode reversal combined mode deflection control method

Microelectromechanical systems (MEMS) gyroscopes with higher precision have always been a focal point of research. Due to limitations in resonant structure, fabrication processes, and measurement and control techniques, MEMS gyroscopes with bias instability better than 0.01°/h are still rare and expensive. This paper incorporates electrode machining error and capacitance detection nonlinear error into the gyroscope model, resulting in a more comprehensive bias output model. Based on this, a mode reversal combined mode deflection control method is proposed to eliminate the thermal drift and decrease the bias instability of the gyroscope. Experimental results demonstrate that compared with the traditional force-to-rebalance mode, the new method achieves a 595 times reduction in bias variation during -40 °C to +60 °C temperature cycles and a 6.3 times reduction in bias instability at room temperature. The average bias instability of honeycomb disk resonator gyroscopes can reach 0.003°/h at integration times of 8500 s after applying the new method across three prototypes, which is the best reported performance of the MEMS gyroscope thus far. This paper provides a new paradigm for achieving higher precision MEMS gyroscopes.