Vibration mode analysis of piezoelectric-ceramic cylinder vibratory gyroscopes with interdigital electrodes

Using the deviation of vibration mode axes from their ideal positions, an equivalent circuit is introduced for bending mode-based cylindrical piezoelectric ceramic vibratory gyroscopes which have interdigital electrodes for both driving and detection. By comparing experimentally determined impedance characteristics with numerically simulated impedance characteristics, it is possible to estimate shifts in a vibration mode axis of a resonator. Furthermore, it is possible to design a high-performance vibratory gyroscope that produces no output voltage even when it is not subjected to an angular velocity by degenerating two vibratory modes. This degeneracy can be induced by laser machining a groove at the high-frequency vibration mode axis.