Compensating Force Imbalance Using Anchored Beam Coupling Mechanism in MEMS Tuning Fork Gyroscope (TFG) Drive Frame Structure

This paper presents an improved tuning fork gyroscope (TFG) structure utilizing two gyroscope drive resonator frames and a diamond-shaped coupling spring mechanism. It explores a two-degree-of-freedom system for the drive mode frame with a coupling mechanism to reduce external vibration sensitivity while keeping angular rate sensitivity. Expressions are derived to study and optimize the coupling spring structure. FEM modeling using ANSYS software validates the expressions that are derived. Simulations were performed to ensure anti-phase motion and avoid structural imbalance induced in-phase motion. Simulations demonstrate compensation for force imbalance and preservation of anti-phase motion. FEM modal analysis confirms a significant frequency separation of 10.90 kHz between in-phase and anti-phase resonant frequencies, with values at 6.81 kHz and 17.713 kHz, respectively. The improved frequency separation in TFG can ensure robustness against external environmental vibrations when fabrication imperfections occur and ensure better reliability for the measurement of angular velocity in inertial sensing applications.