Investigating energy loss mechanisms in an SOI-based tuning-fork gyroscope

Abstract

In light of the efforts to improve the performance of micromachined gyroscopes, this paper presents an investigation of energy loss mechanisms in a SOI-based tuning-fork gyroscope, since these loss mechanisms dictate the value of the mechanical Quality factor (Q) that has been identified as a critical determinant for achieving high-precision performance. The numerical models of thermoelastic damping (TED) and anchor loss in the tuning-fork gyroscope design are created in a FEM software, ANSYS/Multiphysics, according to a thermal-energy method and a separationand- transfer method, respectively. The calculated results indicate that thermoelastic damping is the dominant loss while anchor loss is negligible for the gyroscope design. In order to validate the created models, an experimental study on the Q of the SOI-based tuning-fork gyroscope is consequently conducted. Comparison between the calculated results and the measured data not only validates the numerical models, but also demonstrates the significant effect of fabrication process on the final achievable Q values of the fabricated gyroscopes.