Strong Robustness Quad Mass Gyroscope with the Parallel Coupled Structure Design

This paper reports a strong robustness MEMS QMG with the parallel coupled structure design, for the first time. The motions of the four masses of the gyroscope in the drive and sense directions are coupled and connected through different rings to achieve the parallel coupled effect. We demonstrated that the parallel coupled QMG has stronger robustness by numerical analysis, FEA and experiments. We study the kinematic equations of the parallel coupled QMG and compare it with the serial coupled QMG to analyze the effect of the difference in stiffness matrices and damping mismatch on the gyroscope performance and carry out numerical analyses under the conditions of stiffness mismatch and external vibration, and the results show that the parallel coupled QMG has stronger stiffness robustness and vibration robustness. We applied accelerations of different magnitudes and directions to the parallel and serial QMG to simulate the external loads, and the results show that the bandwidth of the parallel QMG is almost unaffected by the acceleration. We fabricated the parallel coupled QMG prototype using the SOG process, and designed circuits to test the performance. The results indicate that the gyroscope is sensitive to small input angles with 0.0603(degrees)/s/root Hz ARW and 0.0135(degrees)/sBI at 162 Hz frequency mismatch and 30 C-degrees temperature compensation. Moreover, the frequency and quality factor of the parallel QMG are little affected by temperature and the bandwidth remains almost constant with good temperature robustness. These results indicate that the parallel structure has the potential to deliver better performance. 2024-0021