Mechanical Vibration Characteristics for the Driving Part in Array of Microelectromechanical Systems Vibratory Gyroscopes

2012 ◽  
Vol 51 ◽  
pp. 097201
Author(s):  
Yoshinori Miyake ◽  
Masaki Hirata ◽  
Kenichiro Suzuki
Keyword(s):  
Microelectromechanical Systems ◽  
Mechanical Vibration ◽  
Vibration Characteristics ◽  
Vibratory Gyroscopes

Temperature and mechanical vibration characteristics of a miniature long external cavity semiconductor laser

1990 ◽  
Vol 26 (15) ◽  
pp. 1159 ◽  
Author(s):  
S.A. Al-Chalabi ◽  
J. Mellis ◽  
M. Hollier ◽  
K.H. Cameron ◽  
R. Wyatt ◽  
...  
Keyword(s):  
Semiconductor Laser ◽  
Mechanical Vibration ◽  
External Cavity ◽  
Vibration Characteristics

scholarly journals Optically read Coriolis vibratory gyroscope based on a silicon tuning fork

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
N. V. Lavrik ◽  
P. G. Datskos
Keyword(s):  
Tuning Fork ◽  
Microelectromechanical Systems ◽  
Ambient Pressure ◽  
Electrical Contacts ◽  
Wafer Level ◽  
Vibratory Gyroscopes ◽  
Equivalent Rate ◽  
Additional Processing ◽  
On Chip ◽  
Optical Lever

Abstract In this work, we describe the design, fabrication, and characterization of purely mechanical miniature resonating structures that exhibit gyroscopic performance comparable to that of more complex microelectromechanical systems. Compared to previous implementations of Coriolis vibratory gyroscopes, the present approach has the key advantage of using excitation and probing that do not require any on-chip electronics or electrical contacts near the resonating structure. More specifically, our design relies on differential optical readout, each channel of which is similar to the “optical lever” readout used in atomic force microscopy. The piezoelectrically actuated stage provides highly efficient excitation of millimeter-scale tuning fork structures that were fabricated using widely available high-throughput wafer-level silicon processing. In our experiments, reproducible responses to rotational rates as low as 1.8 × 103° h−1 were demonstrated using a benchtop prototype without any additional processing of the raw signal. The noise-equivalent rate, ΩNER, derived from the Allan deviation plot, was found to be <0.5° h−1 for a time of 103 s. Despite the relatively low Q factors (<104) of the tuning fork structures operating under ambient pressure and temperature conditions, the measured performance was not limited by thermomechanical noise. In fact, the performance demonstrated in this proof-of-principle study is approximately four orders of magnitude away from the fundamental limit.

scholarly journals TECHNIQUE OF PROCESSING OF VIBRATION MONITORING DATA, RECEIVED BY THE USE OF MICROELECTROMECHANICAL SYSTEMS

2019 ◽  
Vol 22 (2) ◽  
pp. 38-48
Author(s):  
B. A. Chichkov
Keyword(s):  
Gas Turbines ◽  
Microelectromechanical Systems ◽  
Vibration Characteristics ◽  
Technical State ◽  
Vibration Monitoring ◽  
Microelectromechanical Devices ◽  
Simultaneous Control ◽  
Diagnostic Potential ◽  
Additional Equipment ◽  
Aviation Engines

During the operation of such machines as aviation engines and land based gas turbines, the obligatory vibration monitoring is carried out which is focused on the prevention of their possible damages and destructions during the work on resonant modes or because of material fatigue. Nowadays, as a rule, the standard or additional equipment is used for such control which includes as a component various types of one-axial vibration gauges. In most cases, the control is carried out continuously, and the frequency of registration can differ from several values for a flight to several values in a second. The data received during routine vibration monitoring is peak values of vibrations. They are diagnosed, using the pre-start control and some ways of fit and the tendency of changes of vibration during the operation. Microelectromechanical systems gaining now the increasing distribution (MEMS), as a rule, allow to obtain the data about vibro-acceleration without giving data about the frequency vibration characteristics. But also the regular equipment of vibrational control used during the operation of considered machines does not give data about the frequency vibration characteristics. However, microelectromechanical devices allow to obtain the data with the essential higher frequency of sample rate (in tens and hundreds times) in comparison with mass equipment used now for control, and to carry out the simultaneous control of vibration on three axes using one gauge. Apart from the vibration peak value the position relative to a reference point is fixed. Does the information received according to mentioned above features have better diagnostic potential? Will the array dimension received during data verification be an obstacle to the operational processing? Materials of the present article are an attempt to give answers to these questions and to make representation about possibility and features of an estimation of a technical state of machines by the results of processing of time series vibro-accelerations received with the use of such processing microelectromechanical systems. It is represented that the way of data processing of vibrating monitoring considered in the article at sufficient simplicity of realization allows to solve the problem of an estimation of a technical state of monitoring item.

scholarly journals Analysis of Winding Vibration Characteristics of Power Transformers Based on the Finite-Element Method

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2404 ◽  
Author(s):  
Xiaomu Duan ◽  
Tong Zhao ◽  
Jinxin Liu ◽  
Li Zhang ◽  
Liang Zou
Keyword(s):  
Simulation Model ◽  
Solid Mechanics ◽  
Short Circuit ◽  
Mechanical Vibration ◽  
Simulation Models ◽  
Vibration Signal ◽  
Vibration Characteristics ◽  
Experimental Conditions ◽  
Transformer Winding ◽  
Multiphysics Coupling

The winding is the core component of a transformer, and the technology used to diagnose its current state directly affects the operation and maintenance of the transformer. The mechanical vibration characteristics of a dry-type transformer winding are studied in this paper. A short-circuit test was performed on an SCB10-1000/10 dry-type transformer, and the vibration signal at the surface was measured. Based on actual experimental conditions, a vibration-simulation model of the transformer was established using COMSOL Multiphysics software. A multiphysics coupling simulation of the circuit, magnetic field, and solid mechanics of the transformer was performed on this model. The simulation results were compared with measured data to verify the validity of the simulation model. The simulation model for a transformer operating under normal conditions was then used to develop simulation models of transformer-winding looseness, winding deformation, and winding-insulation failure, and the winding fault vibration characteristics were analyzed. The results provide a basis for detecting and analyzing the mechanical state of transformer windings.

scholarly journals The Potential Influence of Tree Crown Structure on the Ginkgo Harvest

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 366
Author(s):  
Yan Xuan ◽  
Linyun Xu ◽  
Guanhua Liu ◽  
Jie Zhou
Keyword(s):  
Natural Frequency ◽  
Economic Value ◽  
Mechanical Vibration ◽  
Element Model ◽  
Fruit Trees ◽  
Vibration Characteristics ◽  
Damping Coefficient ◽  
Additional Energy ◽  
Frequency Model ◽  
Crown Structure

Ginkgo biloba L. has significant health benefits and considerable economic value, but harvesting the fruit is highly labor-intensive. Mechanical vibration harvesting has been shown effective in harvesting various fruit types. In the study of vibration harvesting, the research on the vibration characteristics of fruit trees focuses on the natural frequency (resonance frequency), model, and damping coefficient, which are the main factors affecting the vibration characteristics of trees. But field harvesting experiments have shown that the tree structure may have an impact on the vibration characteristics of the fruit tree and the efficiency of mechanical harvesting. In addition, the research on the damping coefficient of fruit trees is mainly low-frequency damping, and the relevant results cannot be applied to the actual vibration harvesting frequency range. Applying a natural frequency with low damping coefficient to excite a tree can reduce additional energy dissipation. This study explored the influence of ginkgo crown structure on the vibration characteristics and the law of damping changes with frequency. After counting 273 ginkgo trees, two typical ginkgo crown structures, monopodial branching and sympodial branching, were selected to be analyzed for vibration spectrum and damping coefficient. The vibration models for different crown-shaped ginkgo trees were simulated to analyze the vibration state at different frequencies. For sympodial branching ginkgo trees, the consistency of natural frequencies at different branches was better than monopodial branching ginkgo trees. The finite element model analysis shows that monopodial branching ginkgo trees have mainly partial vibrations at different branches when vibrating at high frequencies. The high-frequency vibrations in sympodial branching reflect the better overall vibration of the canopy. The damping coefficients for the two crown types decreased with the increase in frequency. The monopodial branching damping coefficient was 0.0148–0.0298, and the sympodial branching damping coefficient was slightly smaller at 0.0139–0.0248. Based on the test results, the sympodial branching ginkgo tree has better vibration characteristics. The results indicate that controlling the crown structure of fruit trees to be sympodial branching by pruning may help improve the overall vibration characteristics of fruit trees.

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