Design and performance test of an in-plane gimbaled silicon gyroscope

In this paper, a single DOF in-plane gimbaled silicon gyroscope and capacitive detection circuits are designed, fabricated and experimented. The operational principles of a vibrating silicon gyroscope and in-plane gimbaled silicon gyroscope are explained, and the differences between them are described. Because the latter has inner and outer gimbals separately, the driving and sensing mode is almost decoupled mechanically, which results in performance enhancement. The model equations of the in-plane gimbaled gyroscope are derived. Capacitive detection method with two anti-phase driving signals is used to measure the variation of capacitance. Moreover, two anti-phase carrier signals are added in order to reduce driving and measurement noises and to achieve linear relationship between applied angular rate and sensing output. Through experiments, it is confirmed that the proposed gyroscope and detection circuits have good linear property, resolution and sensitivity, contributing to the performance improvement of a silicon gyroscope