Construction of a low-frequency flat-type piezoelectric vibratory gyroscope

A new low-frequency flat-type piezoelectric vibratory gyroscope structure is proposed here, and is analyzed by the finite-element method. In-plane modes are used for driving and detecting in this structure. The vibratory gyroscope is composed of two tuning forks with an additional mass and the central arm that combines these forks flatly. Moreover, another mass is added to the center of the central arm that changes only the resonant frequency of the detecting mode. Therefore, the difference in the resonant frequencies of both modes can be adjusted by changing the dimensions of the mass. The structure is hardly affected by a support because the displacements at the support part become very small. Using the metal structure with the piezoelectric ceramics for driving and detecting, it was clarified that the vibratory gyroscope operates as an angular rate sensor.