This paper reports a high-performance vibrating ring gyroscope fabricated in (111) oriented single-crystal silicon (SCS). High-performance microgyroscopes are needed in many applications, including inertial navigation, control, and defense/avionics/space. The ring gyroscope provides a number of advantages, including excellent mode matching, high-resolution, low zero-rate output, and long-term stability. In this paper, a SCS vibrating ring gyroscope with high aspect ratio silicon on glass structure was designed, fabricated and tested. The ring is 2.7mm in diameter and 150μm thick. The gyro has the following measured performance: high Q (12000), good nonlinearity (0.02%), large sensitivity (132 mV/°/sec), low output noise (10.4°/hr/Hz) and high resolution (7.2°/hr). The maximum bias shift is less than ±1°/sec over 10 hours without thermal control.

A single-crystal silicon vibrating ring gyroscope

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.

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Huisui Zhang

Papers

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