Gyroscope sensing and self-calibration architecture based on signal phase shift

Abstract

MEMS vibratory gyroscopes measure rotation rates by sensing in various ways the effects of the Coriolis force on the gyroscope dynamics. This paper presents a rotation rate sensing method that is based on the phase shift induced by the Coriolis force in the gyroscope outputs. In principle, this method is applicable to any gyroscope that can be modeled at the functional level as a 2-DOF mass-spring system. Devices of this type include those based on various kinds of vibrating structures, as well as bulk acoustic wave (BAW) gyroscopes. Furthermore, it is shown that the sensing method presented in this paper can be used also for gyroscope calibration with only minor modifications to the control electronics, and without the need for additional moving parts or calibration stage. This is a significant benefit in applications that require in-situ gyroscope calibration.