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

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 295 ◽  
Author(s):  
Pengbo Xiao ◽  
Zhinan Qiu ◽  
Yao Pan ◽  
Shaoliang Li ◽  
Tianliang Qu ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Decay Time ◽  
Great Influence ◽  
Fused Silica ◽  
Q Factor ◽  
Electrostatic Forces ◽  
Cylindrical Resonator ◽  
Vibratory Gyroscopes ◽  
Frequency Mismatch ◽  
Vibrational Characteristics

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.

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

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1032
Author(s):  
Pengbo Xiao ◽  
Zhinan Qiu ◽  
Yiming Luo ◽  
Yao Pan ◽  
Tianliang Qu ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Temperature Variation ◽  
Fused Silica ◽  
Q Factor ◽  
Temperature Drift ◽  
Cylindrical Resonator ◽  
Influence Of Temperature ◽  
Vibratory Gyroscopes ◽  
Frequency Mismatch ◽  
Vibrational Characteristics

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.

scholarly journals Simulations and Experiments on the Vibrational Characteristics of Cylindrical Shell Resonator Actuated by Piezoelectric Electrodes with Different Thicknesses

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yiming Luo ◽  
Tianliang Qu ◽  
Bin Zhang ◽  
Yao Pan ◽  
Pengbo Xiao
Keyword(s):  
Cylindrical Shell ◽  
Resonant Frequency ◽  
Signal To Noise Ratio ◽  
Great Influence ◽  
Element Model ◽  
Vibrational Amplitude ◽  
Driving Voltage ◽  
Electrode Thickness ◽  
Resonant Frequencies ◽  
Vibrational Characteristics

The resonator is the key element of the Coriolis Vibratory Gyroscope (CVG). The vibrational characteristics of the resonator, including the resonant frequency, vibrational amplitude, and Q factor, have a great influence on CVG’s performance. Among them, the vibrational amplitude mainly affects the scale factor and the signal-to-noise ratio, and the Q factor directly determines the precision and drift characteristics of the gyroscope. In this paper, a finite element model of a cylindrical shell resonator actuated by piezoelectric electrodes with different thicknesses is built to investigate the vibrational characteristics. The simulation results indicate that the resonant frequency barely changes with the electrode thickness, whereas the vibrational amplitude is inversely proportional to the electrode thickness under the same driving voltage. Experiments were performed with four resonators and piezoelectric electrodes of four sizes, and results were consistent with simulations. The resonant frequencies of four resonators changed within 0.36% after attaching the piezoelectric electrodes. Meanwhile, with the same driving voltage, it was shown that the vibrational amplitude decreased with the increase of electrode thickness. Moreover, thinner electrodes resulted in better Q factor and therefore better performance. This study may provide useful reference on electrode design of the CVGs.

scholarly journals Effect of Axial Force on the Performance of Micromachined Vibratory Rate Gyroscopes

Sensors ◽  
2010 ◽  
Vol 11 (1) ◽  
pp. 296-309 ◽  
Author(s):  
Zhanqiang Hou ◽  
Dingbang Xiao ◽  
Xuezhong Wu ◽  
Peitao Dong ◽  
Zhihua Chen ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Axial Force ◽  
Great Influence ◽  
Quality Factors ◽  
Resonant Frequencies ◽  
Vibratory Gyroscopes ◽  
Thermal Expansion Coefficients ◽  
Micromachined Gyroscope ◽  
Experimental Values ◽  
Increasing Temperature

It is reported in the published literature that the resonant frequency of a silicon micromachined gyroscope decreases linearly with increasing temperature. However, when the axial force is considerable, the resonant frequency might increase as the temperature increases. The axial force is mainly induced by thermal stress due to the mismatch between the thermal expansion coefficients of the structure and substrate. In this paper, two types of micromachined suspended vibratory gyroscopes with slanted beams were proposed to evaluate the effect of the axial force. One type was suspended with a clamped-free (C-F) beam and the other one was suspended with a clamped-clamped (C-C) beam. Their drive modes are the bending of the slanted beam, and their sense modes are the torsion of the slanted beam. The relationships between the resonant frequencies of the two types were developed. The prototypes were packaged by vacuum under 0.1 mbar and an analytical solution for the axial force effect on the resonant frequency was obtained. The temperature dependent performances of the operated mode responses of the micromachined gyroscopes were measured. The experimental values of the temperature coefficients of resonant frequencies (TCF) due to axial force were 101.5 ppm/°C for the drive mode and 21.6 ppm/°C for the sense mode. The axial force has a great influence on the modal frequency of the micromachined gyroscopes suspended with a C-C beam, especially for the flexure mode. The quality factors of the operated modes decreased with increasing temperature, and changed drastically when the micromachined gyroscopes worked at higher temperatures.

scholarly journals Optical and Electrical Method Characterizing the Dynamic Behavior of the Fused Silica Cylindrical Resonator

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2928 ◽  
Author(s):  
Zhinan Qiu ◽  
Tianliang Qu ◽  
Yao Pan ◽  
Yonglei Jia ◽  
Zhenfang Fan ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Optical Method ◽  
Laser Doppler Vibrometer ◽  
Fused Silica ◽  
Optical Methods ◽  
Q Factor ◽  
Cylindrical Resonator ◽  
Electrical Method ◽  
Frequency Split ◽  
Measurement Efficiency

Fused silica cylindrical resonant gyroscope (CRG) is a novel high-precision solid-wave gyroscope, whose performance is primarily determined by the cylindrical resonator’s frequency split and quality factor (Q factor). The laser Doppler vibrometer (LDV) is extensively used to measure the dynamic behavior of fused silica cylindrical resonators. An electrical method was proposed to characterize the dynamic behavior of the cylindrical resonator to enhance the measurement efficiency and decrease the equipment cost. With the data acquisition system and the designed signal analysis program based on LabVIEW software, the dynamic behavior of the fused silica cylindrical resonator can be analyzed automatically and quickly. We compared all the electrical measurement results with the optical detection by LDV, demonstrating that the fast Fourier transform (FFT) result of the resonant frequency measured by the electrical method was 0.12 Hz higher than that with the optical method. Thus, the frequency split measured by the electrical and optical methods was the same in 0.18 Hz, and the measurement of the Q factor was basically the same in 730,000. We conducted all measurements under the same operation condition, and the optical method was used as a reference, demonstrating that the electrical method could characterize the dynamic behavior of the fused silica cylindrical resonator and enhance the measurement efficiency.

scholarly journals A 5.86 Million Quality Factor Cylindrical Resonator with Improved Structural Design Based on Thermoelastic Dissipation Analysis

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6003
Author(s):  
Libin Zeng ◽  
Yiming Luo ◽  
Yao Pan ◽  
Yonglei Jia ◽  
Jianping Liu ◽  
...  
Keyword(s):  
Quality Factor ◽  
Structural Design ◽  
Fused Silica ◽  
Q Factor ◽  
The Finite Element Method ◽  
Cylindrical Resonator ◽  
Traditional Structure ◽  
Cylindrical Resonators ◽  
Quality Factor Q ◽  
Crucial Parameter

The cylindrical resonator is the core component of cylindrical resonator gyroscopes (CRGs). The quality factor (Q factor) of the resonator is one crucial parameter that determines the performance of the gyroscope. In this paper, the finite element method is used to theoretically investigate the influence of the thermoelastic dissipation (TED) of the cylindrical resonator. The improved structure of a fused silica cylindrical resonator is then demonstrated. Compared with the traditional structure, the thermoelastic Q (QTED) of the resonator is increased by 122%. In addition, the Q factor of the improved cylindrical resonator is measured, and results illustrate that, after annealing and chemical etching, the Q factor of the resonator is significantly higher than that of the cylindrical resonators reported previously. The Q factor of the cylindrical resonator in this paper reaches 5.86 million, which is the highest value for a cylindrical resonator to date.

scholarly journals Experimental Study on Variation of Surface Roughness and Q Factors of Fused Silica Cylindrical Resonators with Different Grinding Speeds

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1052
Author(s):  
Libin Zeng ◽  
Yunfeng Tao ◽  
Yao Pan ◽  
Jianping Liu ◽  
Kaiyong Yang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Low Cost ◽  
Fused Silica ◽  
Q Factor ◽  
Cylindrical Resonator ◽  
Axisymmetric Shell ◽  
Measurement Results ◽  
Q Factors ◽  
Cylindrical Resonators ◽  
Quality Factor Q

For the axisymmetric shell resonator gyroscopes, the quality factor (Q factor) of the resonator is one of the core parameters limiting their performances. Surface loss is one of the dominating losses, which is related to the subsurface damage (SSD) that is influenced by the grinding parameters. This paper experimentally studies the surface roughness and Q factor variation of six resonators ground by three different grinding speeds. The results suggest that the removal of the SSD cannot improve the Q factor continuously, and the variation of surface roughness is not the dominant reason to affect the Q factor. The measurement results indicate that an appropriate increase in the grinding speed can significantly improve the surface quality and Q factor. This study also demonstrates that a 20 million Q factor for fused silica cylindrical resonators is achievable using appropriate manufacturing processes combined with post-processing etching, which offers possibilities for developing high-precision and low-cost cylindrical resonator gyroscopes.

A study on resonant frequency and Q factor tunings for MEMS vibratory gyroscopes

2004 ◽  
Vol 14 (11) ◽  
pp. 1530-1536 ◽  
Author(s):  
Chihwan Jeong ◽  
Seonho Seok ◽  
Byeungleul Lee ◽  
Hyeonched Kim ◽  
Kukjin Chun
Keyword(s):  
Resonant Frequency ◽  
Q Factor ◽  
Vibratory Gyroscopes ◽  
Mems Vibratory Gyroscopes

scholarly journals A digital system for measurement of resonant frequency and Q factor

1982 ◽  
Vol IM-31 (1) ◽  
pp. 18-21 ◽  
Author(s):  
Rajani K. Pandrangi ◽  
Stanislaw S. Stuchly ◽  
Mariusz Barski
Keyword(s):  
Resonant Frequency ◽  
Digital System ◽  
Q Factor

Vibrational Characteristics of Composite Shafts

1999 ◽  
Author(s):  
A. S. Sekhar ◽  
N. Ravi Kumar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Deformation Theory ◽  
Great Influence ◽  
Shear Deformation Theory ◽  
Stacking Sequence ◽  
Shell Elements ◽  
First Order ◽  
Composite Shaft ◽  
Vibrational Characteristics

Abstract The present study aims in performing eigenvalue analysis and unbalance response for a rotor system having a composite shaft, modelled based on first order shear deformation theory using finite element method with shell elements. Different materials such as boron epoxy, carbon epoxy and graphite epoxy have been tried for various stacking sequences. From the study it is clear that the stacking sequence and material have great influence on the vibrational characteristics of composite shafts.

scholarly journals A Geometrical Study on the Roof Tile-Shaped Modes in AlN-Based Piezoelectric Microcantilevers as Viscosity–Density Sensors

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 658 ◽  
Author(s):  
Víctor Ruiz-Díez ◽  
Javier Toledo ◽  
Jorge Hernando-García ◽  
Abdallah Ababneh ◽  
Helmut Seidel ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Quality Factor ◽  
Q Factor ◽  
Liquid Media ◽  
Roof Tile ◽  
Aln Film ◽  
Monitoring Applications ◽  
Media Monitoring ◽  
Comprehensive Study

Cantilever resonators based on the roof tile-shaped modes have recently demonstrated their suitability for liquid media monitoring applications. The early studies have shown that certain combinations of dimensions and order of the mode can maximize the Q-factor, what might suggest a competition between two mechanisms of losses with different geometrical dependence. To provide more insight, a comprehensive study of the Q-factor and the resonant frequency of these modes in microcantilever resonators with lengths and widths between 250 and 3000 µm and thicknesses between 10 and 60 µm is presented. These modes can be efficiently excited by a thin piezoelectric AlN film and a properly designed top electrode layout. The electrical and optical characterization of the resonators are performed in liquid media and then their performance is evaluated in terms of quality factor and resonant frequency. A quality factor as high as 140 was measured in isopropanol for a 1000 × 900 × 10 µm3 cantilever oscillating in the 11th order roof tile-shaped mode at 4 MHz; density and viscosity resolutions of 10−6 g/mL and 10−4 mPa·s, respectively are estimated for a geometrically optimized cantilever resonating below 1 MHz.

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