Finite-Element Analysis of Trident-Type Tuning Fork Resonator for Vibratory Gyroscope

We have investigated the possibility of producing a highly stable piezoelectric vibratory gyroscope. In order to achieve such a gyroscope, a trident-type tuning fork resonator was adopted, because it has good inherent vibrational characteristics for its support conditions. However from a practical viewpoint, the tuning fork must be studied with the aim of achieving very high stability, and high performance as an angular rate sensor. Therefore, we investigated the detailed vibrational displacement characteristics using finite-element methods and showed that unnecessary vibration of the tuning fork influenced the sensitivity of the gyroscope. That is, this paper concerns the dimensional conditions of the tuning fork for decreasing vibrational displacements at its base portion. We also report the measured characteristic of the angular rate sensor using such an improved tuning fork.