Design, Fabrication and Experiment of Double U-Beam MEMS Vibration Ring Gyroscope.

Huiliang Cao,Yingjie Zhang,Jun Tang,Jun Liu,Yunbo Shi,Zhiwei Kou,Xingling Shao,Kun Huang,Yu Liu,Chong Shen,Jinyang Gao

doi:10.3390/mi10030186

Abstract

This study presents a new microelectromechanical system, a vibration ring gyroscope with a double U-beam (DUVRG), which was designed using a combination of mathematical analysis and the finite element method. First, a ring vibration resonator with eight double U-beam structures was developed, and 24 capacitive electrodes were designed for drive and sense according to the advantageous characteristics of a thin-shell vibrating gyroscope. Then, based on the elastic mechanics and thin-shell theory, a mathematical stiffness model of the double U-beam was established. The maximum mode resonant frequency error calculated by the DUVRG stiffness model, finite element analysis (FEA) and experiments was 0.04%. DUVRG structures were manufactured by an efficient fabrication process using silicon-on-glass (SOG) and deep reactive ion etching (DRIE), and the FEA value and theoretical calculation had differences of 5.33% and 5.36% with the measured resonant frequency value, respectively. Finally, the static and dynamic performance of the fabricated DUVRG was tested, and the bias instability and angular random walk were less than 8.86 (°)/h and 0.776 (°)/√h, respectively.

Highlights

Due to the advantages on small volume, low power consumption and easy integration, MEMS gyroscopes, devices and technologies are utilized in more and more civil and military application areas, including the fields of aircraft and vehicle control, automotive safety, energy harvesting, industrial controlling, inertial navigation, attitude determination, micro robot, micro signal detection, equipment fault diagnosis and consumer electronics [1,2,3,4,5,6,7,8,9,10,11]
Due to the difficulty in manufacturing hemispherical resonator gyros and high assembly requirements, it is difficult to achieve mass production. Both the vibrating ring gyroscopes (VRGs) and the hemispherical resonant gyroscopes (HRGs) work based on the inertial effect of the elastic wave, and the specific vibration form is the circular-elliptical bending vibration of the resonant
The maximum mode resonant frequency error calculated by the DUVRG stiffness model and finite element analysis (FEA) is 0.04%

Summary

Introduction

Due to the advantages on small volume, low power consumption and easy integration, MEMS (microelectromechanical system) gyroscopes, devices and technologies are utilized in more and more civil and military application areas, including the fields of aircraft and vehicle control, automotive safety, energy harvesting, industrial controlling, inertial navigation, attitude determination, micro robot, micro signal detection, equipment fault diagnosis and consumer electronics [1,2,3,4,5,6,7,8,9,10,11]. Compared with current MEMS gyro technology such as the tuning tuning fork type, flat vibration type and shell vibration type, HRGs have the advantages of high precision, high dynamic range, strong anti-overload resistance, can directly measure the rotation angle and is convenient for mass production. Due to the difficulty in manufacturing hemispherical resonator gyros and high assembly requirements, it is difficult to achieve mass production Both the vibrating ring gyroscopes (VRGs) and the HRGs work based on the inertial effect of the elastic wave, and the specific vibration form is the circular-elliptical bending vibration of the resonant. Ayazi proposed a kind of fully symmetrical ring gyroscope with a high aspect ratio structure, with a quality factor of 1200, drive mode amplitude of 0.15 μm and resolution of 1 (◦)/s [29,30]. The phase and the amplitude of the sense mode can be obtained as per

DUVRG Stiffness Model

DUVRG stiffness Model

Mode Simulation

MEMS DUVRG

Conclusions and Discussions