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 Trimming of Imperfect Cylindrical Fused Silica Resonators by Chemical Etching

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3596 ◽  
Author(s):  
Yunfeng Tao ◽  
Yao Pan ◽  
Shilong Jin ◽  
Yonglei Jia ◽  
Kaiyong Yang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Solid State ◽  
Theoretical Calculation ◽  
Material Properties ◽  
Chemical Etching ◽  
Fused Silica ◽  
Cylindrical Resonator ◽  
Frequency Split ◽  
Frequency Trimming ◽  
Stiffness Distribution

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.

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 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 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.

scholarly journals A Novel Method for Estimating and Balancing the Second Harmonic Error of Cylindrical Fused Silica Resonators

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 380
Author(s):  
Yunfeng Tao ◽  
Yao Pan ◽  
Jianping Liu ◽  
Yonglei Jia ◽  
Kaiyong Yang ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Second Harmonic ◽  
Low Frequency ◽  
Fused Silica ◽  
Cylindrical Resonator ◽  
Bias Drift ◽  
Good Consistency ◽  
Manufacturing Errors ◽  
Frequency Split ◽  
Novel Method

The cylindrical resonator gyroscope (CRG) is a type of Coriolis vibratory gyroscope which measures the angular velocity or angle through the precession of the elastic wave of the cylindrical resonator. The cylindrical fused silica resonator is an essential component of the CRG, the symmetry of which determines the bias drift and vibration stability of the gyroscope. The manufacturing errors breaking the symmetry of the resonator are usually described by Fourier series, and most studies are only focusing on analyzing and reducing the fourth harmonic error, the main error source of bias drift. The second harmonic error also is one of the obstacles for CRG towards high precision. Therefore, this paper provides a chemical method to evaluate and balance the second harmonic error of cylindrical fused silica resonators. The relation between the frequency split of the n = 1 mode and the second harmonic error of the resonator is obtained. Simulations are performed to analyze the effects of the first three harmonic errors on the frequency splits. The relation between the location of the low-frequency axis of n = 1 mode and the heavy axis of the second harmonic error is also analyzed by simulation. Chemical balancing experiments on two fused silica resonators demonstrate the feasibility of this balancing procedure, and show good consistency with theoretical and simulation analysis. The second harmonic error of the two resonators is reduced by 86.6% and 79.8%, respectively.

scholarly journals Tuneable Q-Factor of MEMS Cantilevers with Integrated Piezoelectric Thin Films

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3842 ◽  
Author(s):  
Martin Fischeneder ◽  
Martin Oposich ◽  
Michael Schneider ◽  
Ulrich Schmid
Keyword(s):  
High Speed ◽  
Laser Doppler Vibrometer ◽  
Wheatstone Bridge ◽  
Mechanical Stimulus ◽  
Q Factor ◽  
Electron Microscopes ◽  
Afm Cantilever ◽  
Piezoelectric Thin Film ◽  
Mems Cantilevers ◽  
Scanning Electron Microscopes

In atomic force microscopes (AFM) a resonantly excited, micro-machined cantilever with a tip is used for sensing surface-related properties. When targeting the integration of AFMs into vacuum environments (e.g., for enhancing the performance of scanning electron microscopes), a tuneable Q-factor of the resonating AFM cantilever is a key feature to enable high speed measurements with high local resolution. To achieve this goal, in this study an additional mechanical stimulus is applied to the cantilever with respect to the stimulus provided by the macroscopic piezoelectric actuator. This additional stimulus is generated by an aluminum nitride piezoelectric thin film actuator integrated on the cantilever, which is driven by a phase shifted excitation. The Q-factor is determined electrically by the piezoelectric layer in a Wheatstone bridge configuration and optically verified in parallel with a laser Doppler vibrometer. Depending on the measurement technique, the Q-factor is reduced by a factor of about 1.9 (electrically) and 1.6 (optically), thus enabling the damping of MEMS structures with a straight-forward and cheap electronic approach.

Optical and Electrical Methods to Measure the Dynamic Behavior of a MEMS Gyroscope Sensor

2005 ◽  
Author(s):  
Alfredo Cigada ◽  
Elisabetta Leo ◽  
Marcello Vanali
Keyword(s):  
Laser Doppler Vibrometer ◽  
Mechanical Parameters ◽  
Mems Sensors ◽  
Electrical Method ◽  
Mems Gyroscope ◽  
Full Characterization ◽  
Design Specifications ◽  
Electrical Methods ◽  
Gyroscope Sensor

A full characterization of the mechanical parameters for vibrating MEMS sensors is required before integrating the mechanical and the electronic part. This is to verify that the main design specifications are fulfilled before sensors are available on the market. The main goal is to accurately establish the well-working devices in the shortest time. In this paper the electrical method based on the measurement of the GND current is used to satisfy this purpose. To check the validity of the achieved results through this method a comparison is done with those obtained through the widely used optical method based on vibration measurements through by means of a Laser Doppler Vibrometer (LDV).

Objective intraoperative assessment of vitreous f loaters localization in YAG-laser vitreolysis

2021 ◽  
pp. 258-261
Author(s):  
B.A. Normaev ◽  
◽  
A.V. Doga ◽  
D.A. Buryakov ◽  
◽  
...  
Keyword(s):  
Optical Method ◽  
Vitreous Cavity ◽  
Optical Methods ◽  
Safe Distance ◽  
Limits Of Agreement ◽  
Yag Laser ◽  
Vitreous Floaters ◽  
Measurement Results ◽  
Key Word ◽  
Ultrasound Assessment

Purpose. To develop an optical method for assessing the localization of vitreous floaters in the vitreous cavity and to evaluate its efficacy compared to ultrasound assessment. Material and methods. The study included 35 patients (35 eyes) with Weiss ring. All the patients underwent echobiometry, as well as measurement of the distance from the vitreous floaters (VF) to the lens posterior capsule or towards retina by ultrasound and developed optical methods. Results. The mathematical modeling and the diopter difference between the slit-lamp oculars were used to develop a formula for the safe position of the VF in the vitreous cavity calculation. A comparative analysis of ultrasound and optical methods measurement results have showed their comparability. The values of the "limits of agreement" with 95% confidence intervals were: -0.02 [-0.07; 0.01] - the lower "consistency limit" and 0.25 [0.20; 0.29] - the upper "consistency limit". The average difference between methods with a 95% confidence interval was 0.11 [0.08; 0.13]. Conclusions. The developed optical method for assessing the safe localization of VF in the vitreous cavity showed comparable results with the ultrasound measurements. Futhermore, optical method allows to intraoperatively control the safe distance from the VF to the intraocular structures, thereby reducing the risk of YAG-vitreolysis complications. Key word: YAG laser vitreolysis, vitreous floaters, safe distance of vitreous floaters.

Sign in / Sign up

Export Citation Format

Share Document