An effective method for improving mechanical stability of vacuum silicon micro-gyroscope

In this paper, an effective method for improving the mechanical stability of vacuum silicon micro-gyroscope was proposed. A relationship between gain sensitivity to variation of parameter and mode separation demonstrated that the sensitivity decreased with the increase of mode separation, and slight fluctuation of mode separation caused by external disturbances dominated the maximum designed value of frequency difference. So the mechanical stability was optimized when the variation of designed value of frequency difference was equal to the fluctuation of mode separation and mechanical gain met application requirement. The simulation results showed that the mechanical stability was enhanced by 12.7%, and the optimum packaging pressure was about 5.3 kPa. The test results demonstrated that the zero drift was approximately improved to 0.9 mV with the nonlinearity of scale factor being 700×10 ^-6. The bandwidth was improved by 3 times, reaching 89 Hz. This method may provide theoretical foundations for the structure parameter optimization of vacuum silicon micro-gyroscope.