Trimming of Imperfect Cylindrical Fused Silica Resonators by Chemical Etching

Abstract

The cylindrical resonator gyroscope (CRG) is a kind of solid-state gyroscope with a wide application market. The cylindrical resonator is the key component of CRG, whose quality factor and symmetry will directly affect the performance of the gyroscope. Due to the material properties and fabrication limitations, the actual resonator always has some defects. Therefore, frequency trimming, i.e., altering the local mass or stiffness distribution by certain methods, is needed to improve the overall symmetry of the resonator. In this paper, we made further derivation based on the chemical trimming theory proposed by Basarab et al. We built up the relation between the frequency split and the balanced mass to determine the mass to be removed. Chemical trimming experiments were conducted on three cylindrical fused silica resonators. The frequency splits of the three resonators were around 0.05 Hz after chemical trimming. The relation between frequency split and balanced mass established from experimental data was consistent with the theoretical calculation. Therefore, frequency split can be reduced to lower than 0.05 Hz under rigorous theoretical calculation and optimized chemical trimming parameters.

Influence of Temperature Variation on the Vibrational Characteristics of Fused Silica Cylindrical Resonators for Coriolis Vibratory Gyroscopes

“…However, the shell thickness and surface state of the machine-made resonators are imperfect, which results in mass and stiffness distribution variations and causes differences between f 1 and f 2. Supposing f 1 > f 2, therefore, the resonator has a pair of principal axes (the high-frequency principal axis, f 1 and the low-frequency principal axis, f 2), and the frequency split is defined as f 1-f 2, which is one of the main error sources in vibratory gyroscopes [28,29].…”

Effects of Normal-Distributed Measurement Error on Frequency Tuning for a Cylindrical Vibratory Gyroscopes

“…The natural frequency difference between the driving mode and the sensing mode is defined as frequency split. In practice, no matter what structure it is, frequency split would exist due to manufacturing errors, which would decrease the performance of vibratory gyroscope [4], [5]. Therefore, a lot of researches about tuning theories and methods are presented [6], [7].…”