Observation and analysis of the quality factor variation behavior in a monolithic fused silica cylindrical resonator

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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.

Section: Frequency Tuning Procedures and Resultsmentioning

confidence: 99%

Decreasing Frequency Splits of Hemispherical Resonators by Chemical Etching

Wang

Pan

et al. 2018

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“…However, it can also be seen from Figure 13 that the control error of energy periodically changes with the azimuth angle of the standing wave, indicating that the effect of energy control is different in different directions. This may be caused by the existence of non-uniform factors such as frequency-mismatch [ 20 , 21 , 22 ] and damping-mismatch [ 23 ] in the HRG. In the future, it will be necessary to add the loop of the control and optimize the control algorithm to suppress the energy fluctuation when the standing wave rotates [ 24 , 25 , 26 ].…”

Section: The Experiments and Analysismentioning

confidence: 99%

The Energy Compensation of the HRG Based on the Double-Frequency Parametric Excitation of the Discrete Electrode

Zhao

Hao²,

Liu³

et al. 2020

In this study, for energy compensation in the whole-angle control of Hemispherical Resonator Gyro (HRG), the dynamical equation of the resonator, which is excited by parametric excitation of the discrete electrode, is established, the stability conditions are analyzed, and the method of the double-frequency parametric excitation by the discrete electrode is derived. To obtain the optimal parametric excitation of the resonator, the total energy stability of the resonator is simulated for the evolution of the resonator vibration with different excitation parameters and the free precession of the standing wave by the parametric excitation. In addition, the whole-angle control of the HRG is designed, and the energy compensation of parametric excitation is proven by the experiments. The results of the experiments show that the energy compensation of the HRG in the whole-angle control can be realized using discrete electrodes with double-frequency parametric excitation, which significantly improves the dynamic performance of the whole-angle control compared to the force-to-rebalance.

“…Coriolis vibratory gyroscopes (CVGs), especially those with axisymmetric shell resonators, have many advantages including high reliability, considerable stability, long life, low power consumption, and a maintenance-free concept, and are widely used in navigation fields and platform stabilization systems [1][2][3][4][5][6][7][8][9]. For this type of gyroscope, there are mainly two types of axisymmetric shell resonators-hemispherical shell resonators and cylindrical shell resonators [10]. The representative products using hemispherical shell resonators include the Northrop Grumman H130 series and the Safran Regys series [11,12].…”

Section: Introductionmentioning

confidence: 99%

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

Peng¹,

Qiu²,

Luo³

et al. 2020

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The fused silica cylindrical resonator is a type of axisymmetric resonator that can be used for Coriolis vibratory gyroscopes. Although the resonant frequency, frequency mismatch, and Q factor are natural properties of the resonator, they can change with temperature. Therefore, the temperature drift severely limits the detection accuracy and bias stability of the gyroscope. In this paper, the influence of temperature variation on the vibrational characteristics of fused silica cylindrical resonators was investigated. Experiments were performed on a fused silica cylindrical resonator coated with Cr/Au films. It was shown that at the temperature range from 253.15 K to 353.15 K, the resonant frequency linearly increased with temperature, the frequency mismatch remained unchanged, and the Q factor gradually increased till about 333.15 K, when it began to decrease. Meanwhile, the change of thermoelastic damping with temperature may dominate the variation of Q factor at the temperature range from 253.15 K to 353.15 K. This phenomenon was theoretically analyzed and the variation trends of results were consistent with the theoretical analysis. This study indicates that, for the fused silica cylindrical resonator, to discover the influence of temperature variation on the resonant frequency, frequency mismatch, and Q factor, there are certain rules to follow and repeat. The relationship between temperature and frequency can be established, which provides the feasibility of using self-calibration based on temperature characteristics of the resonator for temperature drift compensations. Additionally, there is an optimum temperature that may improve the performance of the Coriolis vibratory gyroscope with the fused silica cylindrical resonator.