Research on the non-ideal dynamics of a dual-mass silicon micro-gyroscope

This study explores the non-ideal dynamics of a dual-mass silicon micro-gyroscope (DSMG). The operating principle and description of the DSMG are interpreted. Under the in-phase, anti-phase, and single-mass excitation conditions, the motion characteristics of the drive mode and sense mode are deduced. The non-ideal dynamics of the drive and sense modes with stiffness errors are analyzed. Then, the finite element simulation of the DSMG with a stiffness error is implemented to verify the non-ideal dynamics. Simulation results demonstrate that the left and right masses share the same natural frequencies in the in-phase or anti-phase drive modes even with the existence of stiffness errors. However, a significant amplitude difference between the left and right proof masses can be observed in the in-phase and anti-phase drive modes. The harmonic response analysis proves that the in-phase drive mode is activated even under anti-phase excitation conditions. Finally, sweep frequency experiments are performed on the fabricated DSMG to verify the correctness of the theoretical analysis. Experimental results indicate that the in-phase and anti-phase modes are excited simultaneously under both the anti-phase and in-phase excitation conditions because of the stiffness errors resulting from fabrication errors. This outcome is consistent with the theoretical analysis and simulation.