An overlapping peak separation algorithm based on multiorder differential method and genetic algorithm for magnetic eddy current signal of a defect cluster

2019 ◽  
Vol 39 (S1) ◽  
Author(s):  
Jingyi Xiong ◽  
Wei Liang ◽  
Xiaobin Liang ◽  
Meng Zhang
Keyword(s):  
Genetic Algorithm ◽  
Eddy Current ◽  
Differential Method ◽  
Defect Cluster ◽  
Current Signal ◽  
Separation Algorithm ◽  
Peak Separation

Real-time wavelet denoising for pulsed eddy current signal based on heterogeneous dual-core

2013 ◽  
Vol 33 (3) ◽  
pp. 866-870
Author(s):  
Xuanbing QIU ◽  
Jilin WEI ◽  
Xiaochao CUI ◽  
Chunhua XIA
Keyword(s):  
Real Time ◽  
Eddy Current ◽  
Wavelet Denoising ◽  
Current Signal ◽  
Pulsed Eddy Current ◽  
Dual Core

scholarly journals Film Thickness-Profile Measurement Using Iterative Peak Separation Structured Illumination Microscopy

2021 ◽  
Vol 11 (7) ◽  
pp. 3023
Author(s):  
Kejun Yang ◽  
Chenhaolei Han ◽  
Jinhua Feng ◽  
Yan Tang ◽  
Zhongye Xie ◽  
...  
Keyword(s):  
Modulation Depth ◽  
Thickness Distribution ◽  
Detection Threshold ◽  
Profile Measurement ◽  
Structured Illumination ◽  
Structured Illumination Microscopy ◽  
Separation Algorithm ◽  
Peak Separation ◽  
Lower Detection ◽  
Depth Response

The surface and thickness distribution measurement for transparent film is of interest for electronics and packaging materials. Structured illumination microscopy (SIM) is a prospective technique for measuring film due to its high accuracy and efficiency. However, when the distance between adjacent layers becomes close, the peaks of the modulation depth response (MDR) start to overlap and interfere with the peak extraction, which restricts SIM development in the field of film measurement. In this paper, an iterative peak separation algorithm is creatively applied in the SIM-based technique, providing a precise peak identification even as the MDR peaks overlap and bend into one. Compared with the traditional method, the proposed method has a lower detection threshold for thickness. The experiments and theoretical analysis are elaborated to demonstrate the feasibility of the mentioned method.

Investigation of magnet segmentation techniques for eddy current losses reduction in permanent magnets electrical machines

2015 ◽  
Vol 34 (1) ◽  
pp. 46-60 ◽  
Author(s):  
Belli Zoubida ◽  
Mohamed Rachid Mekideche
Keyword(s):  
Genetic Algorithm ◽  
Finite Elements ◽  
Eddy Current ◽  
Permanent Magnets ◽  
Skin Effect ◽  
Electrical Machines ◽  
Design Parameters ◽  
Finite Elements Analysis ◽  
Eddy Current Losses ◽  
Content Type

Purpose – Reducing eddy current losses in magnets of electrical machines can be obtained by means of several techniques. The magnet segmentation is the most popular one. It imposes the least restrictions on machine performances. This paper investigates the effectiveness of the magnet circumferential segmentation technique to reduce these undesirable losses. The full and partial magnet segmentation are both studied for a frequency range from few Hz to a dozen of kHz. To increase the efficiency of these techniques to reduce losses for any working frequency, an optimization strategy based on coupling of finite elements analysis and genetic algorithm is applied. The purpose of this paper is to define the parameters of the total and partial segmentation that can ensure the best reduction of eddy current losses. Design/methodology/approach – First, a model to analyze eddy current losses is presented. Second, the effectiveness of full and partial magnet circumferential segmentation to reduce eddy loss is studied for a range of frequencies from few Hz to a dozen of kHz. To achieve these purposes a 2-D finite element model is developed under MATLAB environment. In a third step of the work, an optimization process is applied to adjust the segmentation design parameters for best reduction of eddy current losses in case of surface mounted permanent magnets synchronous machine. Findings – In case of the skin effect operating, both full and partial magnet segmentations can lead to eddy current losses increases. Such deviations of magnet segmentation techniques can be avoided by an appropriate choice of their design parameters. Originality/value – Few works are dedicated to investigate partial magnet segmentation for eddy current losses reduction. This paper studied the effectiveness and behaviour of partial segmentation for different frequency ranges. To avoid eventual anomalies related to the skin effect an optimization process based on the association of the finite elements analysis to genetic algorithm method is adopted.

Defect Sizing Simulation Studies for the Tone-Burst Eddy Current Thermography Using Genetic Algorithm Based Inversion

2012 ◽  
Vol 31 (4) ◽  
pp. 342-348 ◽  
Author(s):  
N. Biju ◽  
N. Ganesan ◽  
C. V. Krishnamurthy ◽  
Krishnan Balasubramaniam
Keyword(s):  
Genetic Algorithm ◽  
Eddy Current ◽  
Tone Burst ◽  
Simulation Studies

Rapid Defect Reconstruction Based on Genetic Algorithm and Similar Model in Remote Field Eddy Current Non-Destructive Testing

2014 ◽  
Vol 518 ◽  
pp. 269-274 ◽  
Author(s):  
Xiao Jie Xu ◽  
Wen Lin Pei
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Eddy Current ◽  
Non Destructive Testing ◽  
Similar Model ◽  
Destructive Testing ◽  
Defect Reconstruction ◽  
Element Computation ◽  
Non Destructive ◽  
Finite Element Computation

Defect reconstruction of remote field eddy current belonged to electromagnetic inverse problem in materia Non-Destructive Testing. In view of disadvantages in present defect reconstruction methods, such as over-long time or excessive need for training samples, a new defect reconstruction method based on similar model and genetic algorithm was investigated as follows: similar model between non-axisymetric defect and axisymetric defect was represented, and proportionality factor was deduced by skin depth equation. As a result, the time-consuming forward problem solution in defect reconstruction, which using 3D finite element computation conventionally, was simplified to 2D finite element computation. At the same time, a method designed to accelerate convergence of genetic algorithm was adopted, and more times saving were obtained. Computation results show that, total defect reconstruction time is reduced to 7.6%, compared with directly 3D finite elemet computation, while reconstruction accuracy remains almost the same.

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