Frequency-Mismatch-Tolerant Silicon Vibratory Gyroscope without Vacuum Package for Automotive Applications

TLDR: A low-cost silicon vibratory gyroscope that tolerates a relatively large mismatch between the driving-mode and sensing-mode frequencies is described in this article. But it does not have the capability to operate at sub-degree-per-second angular rate sensitivity.

Abstract: This paper describes a low-cost silicon vibratory gyroscope that tolerates a relatively large mismatch between the driving-mode and sensing-mode frequencies. The gyroscope is based on beam-mass structure and realized by one silicon proof mass and two beams for the driving and sensing mode. Piezoelectric actuation is used to produce a large driving mode vibration displacement (about 100 mum) with about 32 Vpeak-to-peak. Two tiny sensing beams are separated from the vertical silicon beam to increase the sensitivity while keeping the sensing-mode resonant frequency high. Piezoresistive and piezoelectrical sensing mechanisms are applied to two different gyroscopes. The gyroscope operating at 1-4 kHz is capable of sub-degree-per-second angular rate sensitivity without any vacuum package.