A Digital Closed-Loop Control Method for a MEMS Quadruple Mass Gyroscope

To address the issues of quadrature stiffness coupling and mode frequency splitting in MEMS quadruple mass gyroscopes, a digital closed-loop control method for MEMS quadruple mass gyroscopes is proposed. First, a quadrature stiffness coupling correction method is used to suppress quadrature errors in the MEMS quadruple mass gyroscope, reducing the impact of these errors on the accuracy of angular rate detection. Next, an electrostatic negative stiffness tuning technique is employed to achieve one-time mode matching for the gyroscope, enhancing its signal-to-noise ratio. Finally, force balance mode is used to detect angular rate, improving the gyroscope's operational bandwidth and reducing nonlinearity. Experimental results show that with this method, the bias instability of the MEMS quadruple mass gyroscope is 0.55°/h, and the angle random walk is 0.31 °/ √b. The experimental results demonstrate that the MEMS quadruple mass gyroscope using this digital closed-loop control method achieves high performance and accuracy.