Influence of Electrostatic Forces on the Vibrational Characteristics of Resonators for Coriolis Vibratory Gyroscopes.

Pengbo Xiao,Zhongqi Tan,Yao Pan,Hui Luo,Wanliang Zhao,Kaiyong Yang,Shiqiao Qin,Jianping Liu,Zhinan Qiu,Tianliang Qu,Shaoliang Li

doi:10.3390/s20010295

Pengbo Xiao, Zhongqi Tan + Show 9 more

Open Access

https://doi.org/10.3390/s20010295

Copy DOI

Abstract

The Coriolis Vibratory Gyroscopes are a type of sensors that measure angular velocities through the Coriolis effect. The resonator is the critical component of the CVGs, the vibrational characteristics of which, including the resonant frequency, frequency mismatch, Q factor, and Q factor asymmetry, have a great influence on the performance of CVG. The frequency mismatch and Q factor of the resonator, in particular, directly determine the precision and drift characteristics of the gyroscope. Although the frequency mismatch and Q factor are natural properties of the resonator, they can change with external conditions, such as temperature, pressure, and external forces. In this paper, the influence of electrostatic forces on the vibrational characteristics of the fused silica cylindrical resonator is investigated. Experiments were performed on a fused silica cylindrical resonator coated with Cr/Au films. It was shown that the resonant frequency, frequency mismatch, and the decay time slightly decreased with electrostatic forces, while the decay time split increased. Lower capacitive gaps and larger applied voltages resulted in lower frequency mismatch and lower decay time. This phenomenon was theoretically analyzed, and the variation trends of results were consistent with the theoretical analysis. This study indicates that, for fused silica cylindrical resonator with electrostatic transduction, the electrostatic influence on the Q factor and frequency, although small, should be considered when designing the capacitive gap and choosing bias voltages.

Highlights

The Coriolis vibratory gyroscope (CVG) is a type of inertial device measuring angular velocity through the precession of elastic waves
This paper intends to report the experimental results on the changes of resonant frequency, frequency mismatch, decay time, and decay time split under electrostatic forces, and provide theoretical analysis on these changes
The resonant frequency in measurements and in f1 is the resonant frequency of the low-frequency principal axis, t1 is the decay time, f2 ‒ f1 is the and in practice of the resonator are, respectively, 7473.767 Hz and 7473.745 Hz, which decreases by practice ofmismatch, the resonator

Summary

Introduction

The Coriolis vibratory gyroscope (CVG) is a type of inertial device measuring angular velocity through the precession of elastic waves. The hemispherical resonator gyroscopes (HRGs) have claimed 30 million hours of continuous operation without a single mission failure [9]. For this type of gyroscopes, there are mainly three types of excitation and detection, including electrostatic, electromagnetic, and piezoelectric methods [10]. The representative products using electrostatic methods include the Northrop Grumman H130 series [11] and the Safran HRG CrystalTM. The representative products with piezoelectric transduction include Watson Inc

Methods

Results

Conclusion