Decreasing Frequency Splits of Hemispherical Resonators by Chemical Etching.

Yuting Wang,Yao Pan,Kaiyong Yang,Hui Luo,Tianliang Qu,Yonglei Jia

doi:10.3390/s18113772

Yuting Wang, Yao Pan + Show 4 more

Open Access

https://doi.org/10.3390/s18113772

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Abstract

The hemispherical resonator gyroscope (HRG) has attracted the interest of the world inertial navigation community because of its exceptional performance, ultra-high reliability and its potential to be miniaturized. These devices achieve their best performance when the differences in the frequencies of the two degenerate working modes are eliminated. Mechanical treatment, laser ablation, ion-beams etching, etc., have all been applied for the frequency tuning of resonators, however, they either require costly equipment and procedures, or alter the quality factors of the resonators significantly. In this paper, we experimentally investigated for the first time the use of a chemical etching procedure to decrease the frequency splits of hemispherical resonators. We provide a theoretical analysis of the chemical etching procedure, as well as the relation between frequency splits and mass errors. Then we demonstrate that the frequency split could be decreased to below 0.05 Hz by the proposed chemical etching procedure. Results also showed that the chemical etching method caused no damage to the quality factors. Compared with other tuning methods, the chemical etching method is convenient to implement, requiring less time and labor input. It can be regarded as an effective trimming method for obtaining medium accuracy hemispherical resonator gyroscopes.

Highlights

The hemispherical resonator gyroscope (HRG) is a kind of Coriolis vibratory gyroscope (CVG)well-known for its high performance, small size, light weight, low power consumption and maintenance-free concept [1]
This paper mainly focuses on reducing M4, which is the cause of the frequency split of the resonator and the main sources of bias and random errors in HRGs
We have demonstrated with experiments the decreasing frequency splits of fused silica hemispherical resonators by the method of chemical etching for the first time

Summary

Introduction

The hemispherical resonator gyroscope (HRG) is a kind of Coriolis vibratory gyroscope (CVG). For a specific hemispherical resonator, the amount of the mass to be removed or added can be calculated according to its initial frequency split, and the principle vibrating axes are easy to determine experimentally.

Simulation

Eigen frequencies of the the

Figure

The frequency split change

Quality

Conclusions