A New Thickness Shear Mode Vibratory Gyroscope with Acoustic Gaps Between Pairs of Electrodes

Abstract

A new thickness shear mode vibratory gyroscope which employed the thickness shear mode at both the driving and sensing electrodes was presented. The thickness shear mode shape changed slightly with the Coriolis force, and this change could be detected by the sensing electrode separated from the driving electrode by an acoustic gap. Vibrating tines normal to the plate surface were placed along the acoustic gap. These tines were tuned to resonate with the harmonic Coriolis force caused by the angular rotation of the plate about its plate thickness axis. The change in vibration of the tines with the Coriolis force caused a change in charge or voltage at the sensing electrodes. Since the AT-cut resonators are known to have good f-T curves and long term aging, the new AT-cut gyroscope would have the advantages of a highly stable quartz AT-cut resonator.