scholarly journals Study of Three-Component FBG Vibration Sensor for Simultaneous Measurement of Vibration, Temperature, and Verticality

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jiang Shan-chao ◽  
Wang Jing ◽  
Sui Qing-mei ◽  
Ye Qing-lin ◽  
Wang Li-jun
Keyword(s):  
Simultaneous Measurement ◽  
Matrix Theory ◽  
Coefficient Matrix ◽  
Angle Measurement ◽  
Vibration Sensor ◽  
Measurement Sensitivity ◽  
Hilbert Huang Transform ◽  
Measurement Experiment ◽  
Project Matrix ◽  
Metal Diaphragm

To achieve simultaneous measurement of measurand vibration, temperature, and verticality, a three-component fiber Brag grating (TVFBG) vibration sensor is proposed in this paper. Polymer and metal diaphragm sensitization methods are utilized to improve this sensor measurement sensitivity. Project matrix theory is adopted to analyze this sensor. Theoretically,9×9nonsingular measuring coefficient matrix of this TVFBG sensor made up by three3×3measurand coefficient matrixes is established. In order to effectively extract measurand, Hilbert-Huang transform (HHT) is accepted to process this sensor’s center wavelength signals. Calibration experiments are carried out to verify the performance of this TVFBG sensor. Experiment data confirm that this sensor has excellent frequency response and show good linearity at temperature and verticality measurement. Wrist rotation angle measurement experiment is also implemented to further identify this sensor practical value. Through analyzing by HHT, experiment results show that the angle measurement sensitivities of three fiber Brag gratings which are included in this sensor are separately 25.2 pm/°, 38.2 pm/°, and 38.3 pm/°.

scholarly journals A Fiber Bragg Grating Based Torsional Vibration Sensor for Rotating Machinery

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2669 ◽  
Author(s):  
Jingjing Wang ◽  
Li Wei ◽  
Ruiya Li ◽  
Qin Liu ◽  
Lingling Yu
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Torsional Vibration ◽  
Electromagnetic Interference ◽  
Vibration Sensor ◽  
Vibration Measurement ◽  
Bragg Grating ◽  
Structural Parameter ◽  
Measurement Sensitivity ◽  
Fiber System

This paper proposes a new type of torsional vibration sensor based on fiber Bragg grating (FBG). The sensor has two mass ball optical fiber systems. The optical fiber is directly treated as an elastomer and a mass ball is fixed in the middle of the fiber in each mass ball fiber system, which is advantageously small, lightweight, and has anti-electromagnetic interference properties. The torsional vibration signal can be calculated by the four FBGs’ wavelength shifts, which are caused by mass balls. The difference in the two sets of mass ball optical fiber systems achieves anti-horizontal vibration and anti-temperature interference. The principle and model of the sensor, as well as numerical analysis and structural parameter design, are introduced. The experimental conclusions show that the minimum torsional natural frequency of the sensor is 27.35 Hz and the torsional vibration measurement sensitivity is 0.3603 pm/(rad/s2).

Induction Motor Multi-Fault Analysis Based on Intrinsic Mode Functions in Hilbert-Huang Transform

2009 ◽  
Author(s):  
Xin Xue ◽  
V. Sundararajan
Keyword(s):  
Induction Motor ◽  
Experimental Studies ◽  
Current Data ◽  
Fault Analysis ◽  
Vibration Sensor ◽  
Intrinsic Mode Functions ◽  
Experimental Conditions ◽  
Classification Rate ◽  
Multiple Faults ◽  
Hilbert Huang Transform

This paper reports experimental studies to detect two faults in a 3-phase 1.5hp induction motor using intrinsic mode functions from Hilbert-Huang transform. The faults studied are the eccentricity of the air-gap between the rotor and stator and damage to the outer race of bearings. The experiments are conducted under four conditions: the normal no-fault condition, two single fault conditions and the multiple faults condition. Two microphones, one vibration sensor and one current sensor are used to collect sound, vibration and current data respectively. The data is analyzed using the Hilbert-Huang transform and Fast Fourier Transform. Features are extracted from the spectrum of intrinsic mode functions and the average value of their envelope. Three simple classifiers are used to classify these four experimental conditions. The results demonstrate that the multiple sensors do improve the classification rate and that the Intrinsic Mode Functions obtained by the Hilbert-Huang transform are more effective than FFT in classifying multiple faults.

scholarly journals LU Decomposition Scheme for Solving m-Polar Fuzzy System of Linear Equations

2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Ali N. A. Koam ◽  
Muhammad Akram ◽  
Ghulam Muhammad ◽  
Nawab Hussain
Keyword(s):  
Fuzzy System ◽  
Matrix Theory ◽  
Linear Equations ◽  
Coefficient Matrix ◽  
Least Square ◽  
System Of Linear Equations ◽  
Fuzzy Matrix ◽  
Decomposition Scheme ◽  
Symmetric Positive Definite ◽  
Generalized Inverse Matrix

This paper presents a new scheme for solving m-polar fuzzy system of linear equations (m-PFSLEs) by using LU decomposition method. We assume the coefficient matrix of the system is symmetric positive definite, and we discuss this point in detail with some numerical examples. Furthermore, we investigate the inconsistent m×nm-polar fuzzy matrix equation (m-PFME) and find the least square solution (LSS) of this system by using generalized inverse matrix theory. Moreover, we discuss the strong solution of m-polar fuzzy LSS of the inconsistent m-PFME. In the end, we present a numerical example to illustrate our approach.

scholarly journals Convergence of Gossip Algorithms for Consensus in Wireless Sensor Networks with Intermittent Links and Mobile Nodes

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Shaochuan Wu ◽  
Jiayan Zhang ◽  
Yuguan Hou ◽  
Xu Bai
Keyword(s):  
Matrix Theory ◽  
Mean Squared Error ◽  
Nonnegative Matrix ◽  
Coefficient Matrix ◽  
Mobile Nodes ◽  
Gossip Algorithms ◽  
Squared Error ◽  
Strongly Connected ◽  
The Cost ◽  
Intermittent Links

We study the convergence of pairwise gossip algorithms and broadcast gossip algorithms for consensus with intermittent links and mobile nodes. By nonnegative matrix theory and ergodicity coefficient theory, we prove gossip algorithms surely converge as long as the graph is partitionally weakly connected which, in comparison with existing analysis, is the weakest condition and can be satisfied for most networks. In addition we characterize the supremum for the mean squared error of convergence as a function associated with the initial states and the number of nodes. Furthermore, on the condition that the graph is partitionally strongly connected, the rate of convergence is proved to be exponential and governed by the second largest eigenvalue of expected coefficient matrix. For partitionally strongly connected digraphs, simulation results illustrate that gossip algorithms actually converge, and broadcast gossip algorithms can converge faster than pairwise gossip algorithms at the cost of larger error of convergence.

LU Decomposition method to solve bipolar fuzzy linear systems

2020 ◽  
Vol 39 (3) ◽  
pp. 3329-3349 ◽  
Author(s):  
Muhammad Akram ◽  
Ghulam Muhammad ◽  
Tofigh Allahviranloo ◽  
Nawab Hussain
Keyword(s):  
Decomposition Method ◽  
Matrix Theory ◽  
Coefficient Matrix ◽  
Least Square ◽  
Lu Decomposition ◽  
Fuzzy Matrix ◽  
Linear System Of Equations ◽  
Fuzzy Environment ◽  
Generalized Inverse Matrix ◽  
Fuzzy Linear Systems

The aim of this work is to solve the linear system of equations using LU decomposition method in bipolar fuzzy environment. We assume a special case when the coefficient matrix of the system is symmetric positive definite. We discuss this point in detail by giving some numerical examples. Moreover, we investigate m × n inconsistent bipolar fuzzy matrix equation and find the least square solution of the inconsistent bipolar fuzzy matrix using the generalized inverse matrix theory. The existence of the strong bipolar fuzzy least square solution of the inconsistent bipolar fuzzy matrix is discussed. In the end, a numerical example is presented to illustrate our proposed method.

Label-free, mass-sensitive single-molecule imaging using interferometric scattering microscopy

2020 ◽  
Author(s):  
Nikolas Hundt
Keyword(s):  
Single Molecule ◽  
Cellular Systems ◽  
Single Molecule Imaging ◽  
Label Free ◽  
Measurement Sensitivity ◽  
Mass Distributions ◽  
Quantitative Measurements ◽  
Contrast Mechanism ◽  
Cellular Components ◽  
Scattering Signal

Abstract Single-molecule imaging has mostly been restricted to the use of fluorescence labelling as a contrast mechanism due to its superior ability to visualise molecules of interest on top of an overwhelming background of other molecules. Recently, interferometric scattering (iSCAT) microscopy has demonstrated the detection and imaging of single biomolecules based on light scattering without the need for fluorescent labels. Significant improvements in measurement sensitivity combined with a dependence of scattering signal on object size have led to the development of mass photometry, a technique that measures the mass of individual molecules and thereby determines mass distributions of biomolecule samples in solution. The experimental simplicity of mass photometry makes it a powerful tool to analyse biomolecular equilibria quantitatively with low sample consumption within minutes. When used for label-free imaging of reconstituted or cellular systems, the strict size-dependence of the iSCAT signal enables quantitative measurements of processes at size scales reaching from single-molecule observations during complex assembly up to mesoscopic dynamics of cellular components and extracellular protrusions. In this review, I would like to introduce the principles of this emerging imaging technology and discuss examples that show how mass-sensitive iSCAT can be used as a strong complement to other routine techniques in biochemistry.

Reconstruction of complex shaped crack from ECT signals based on a fast forward solver using an advanced multi-media element

2020 ◽  
Vol 64 (1-4) ◽  
pp. 621-629
Author(s):  
Yingsong Zhao ◽  
Cherdpong Jomdecha ◽  
Shejuan Xie ◽  
Zhenmao Chen ◽  
Pan Qi ◽  
...  
Keyword(s):  
Coefficient Matrix ◽  
Crack Edge ◽  
Numerical Accuracy ◽  
Gauss Point ◽  
Current Testing ◽  
Efficient Simulation ◽  
Shaped Crack ◽  
Multi Media ◽  
Profile Reconstruction ◽  
Crack Profile

In this paper, the conventional database type fast forward solver for efficient simulation of eddy current testing (ECT) signals is upgraded by using an advanced multi-media finite element (MME) at the crack edge for treating inversion of complex shaped crack. Because the analysis domain is limited at the crack region, the fast forward solver can significantly improve the numerical accuracy and efficiency once the coefficient matrices of the MME can be properly calculated. Instead of the Gauss point classification, a new scheme to calculate the coefficient matrix of the MME is proposed and implemented to upgrade the ECT fast forward solver. To verify its efficiency and the feasibility for reconstruction of complex shaped crack, several cracks were reconstructed through inverse analysis using the new MME scheme. The numerical results proved that the upgraded fast forward solver can give better accuracy for simulating ECT signals, and consequently gives better crack profile reconstruction.

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