Electrostatic Compensation of Structural Imperfections in Dynamically Amplified Dual-Mass Gyroscope

This paper presents a study on dynamics of a dual-mass MEMS vibratory gyroscope in presence of imperfections and reports a method for precision electrostatic frequency tuning of the operational modes. The presented tuning algorithm involves, first, assessing the modes mismatch using the experimental frequency responses of both proof-masses, followed by the identification of the stiffness mismatch along the two axes and anisoelasticity angles alpha and beta, then choosing the tuning voltages for modification of the diagonal, off-diagonal, and coupling terms in the stiffness matrix. Results of simulation are verified using experimental electrostatic frequency tuning of a dynamically amplified gyroscope. The frequency split between the operational modes was reduced from 26 Hz down to 50 mHz, resulting in 17x increase in the gyroscope scale factor.