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A Quantification Method for Length of Axial Flux Leakage Signal

A technology of signal length and axial flux leakage, applied in the direction of material magnetic variables, etc., can solve problems such as defect length, and achieve the effect of reducing influence and improving robustness

Active Publication Date: 2019-12-13
BEIJING HUAHANG RADIO MEASUREMENT & RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is: to solve the problem of inversion of defect length according to leakage magnetic field signal

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  • A Quantification Method for Length of Axial Flux Leakage Signal
  • A Quantification Method for Length of Axial Flux Leakage Signal
  • A Quantification Method for Length of Axial Flux Leakage Signal

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Embodiment Construction

[0053] The technical solutions of the present invention will be further explained and described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0054] A method for quantifying the length of an axial magnetic flux leakage signal, the method comprising:

[0055] 1. Feature extraction and fusion of MFL signal length;

[0056] The specific implementation steps are:

[0057] ①Differential length feature extraction

[0058] Let the magnetic flux leakage signal be expressed as S(x), and calculate its differential signal S'(x)

[0059]

[0060] Let the difference Ld between the maximum value and minimum value of the differential signal S'(x) on the horizontal axis be the differential length feature.

[0061] ②Fixed threshold feature extraction

[0062] Taking the maximum value of the magnetic flux leakage signal S(x) multiplied by the proportional coefficient ρ as the threshold T, the axial length Lt intercepted by the threshold T is th...

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Abstract

The invention relates to an axial flux leakage signal length quantitative method. The method specifically comprises the following realization steps: firstly, extracting a fixed threshold feature and differential length feature of a flaw signal, to obtain a signal length feature according to fusion strategy, then extracting a circumferential signal feature and signal amplitude feature, and finally, establishing the length quantitation equation according to inside and outside attributes of flaw, and resolving the unkown parameters of a known flaw sample to obtain a length quantitation model. The method is applicable to both internal and external wall flaw length quantitation; the influence of speed factor on the length quantitation results can be effectively reduced; and by adopting stable feature as a quantitative input, the robustness of the method can be improved.

Description

technical field [0001] The invention belongs to the field of magnetic flux leakage defect signal quantification, and in particular relates to a method for quantifying the length of an axial magnetic flux leakage signal, which is used to solve the problem of defect length inversion of a magnetic field leakage signal. Background technique [0002] In order to grasp the corrosion situation of oil and gas pipelines and ensure the safety and reliability of pipeline operation, the detection technology of oil and gas pipelines has been developed rapidly. Defects, geometric deformations and their exact positions provide the basis for safety evaluation and integrity management of pipelines, and are necessary means for timely maintenance, technical transformation, future design and construction of pipelines, and prolonging pipeline life. The magnetic flux leakage internal detection method is currently the most widely used and best detection technology for oil and gas pipeline flaw det...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N27/83
CPCG01N27/83
Inventor 魏宁郑莉李娜呼婧
Owner BEIJING HUAHANG RADIO MEASUREMENT & RES INST