Application of empirical mode decomposition in early diagnosis ofmagnetic memory signal

来源期刊：中南大学学报(英文版)2010年第3期

论文作者：冷建成 徐敏强 张嘉钟

文章页码：549 - 553

Key words：metal magnetic memory; noise interference; early diagnosis; empirical mode decomposition; magnetic field gradient; stress concentration; zones; envelop analysis

Abstract: In order to eliminate noise interference of metal magnetic memory signal in early diagnosis of stress concentration zones and metal defects, the empirical mode decomposition method combined with the magnetic field gradient characteristic was proposed. A compressive force periodically acting upon a casing pipe led to appreciable deformation, and magnetic signals were measured by a magnetic indicator TSC-1M-4. The raw magnetic memory signal was first decomposed into different intrinsic mode functions and a residue, and the magnetic field gradient distribution of the subsequent reconstructed signal was obtained. The experimental results show that the gradient around 350 mm represents the maximum value ignoring the marginal effect, and there is a good correlation between the real maximum field gradient and the stress concentration zone. The wavelet transform associated with envelop analysis also exhibits this gradient characteristic, indicating that the proposed method is effective for early identifying critical zones.

基金信息：the PhD Programs Foundations of Ministry of Education of China
the Natural Science Foundation of Heilongjiang Province, China
the National Natural Science Foundation of China