【摘要】 针对埋地钢质管道损伤不开挖检测问题,提出一种非接触式谐波磁场检测方法。利用调频载波原理将高频信号叠加到低频信号上构建谐波激励信号,通过聚焦阵列增强激励信号的空间辐射能量和靶向性;采用三维矢量隧道磁阻差分传感器阵列对磁场信号进行采集。采用双稳随机共振(SR)算法增强目标信号能量并采用局域均值分解(LMD)算法进行自适应时频分析。仿真与实验结果表明,该检测方法能够对缺陷信号进行有效提取与辨识,实现埋地管道损伤的不开挖检测。更多还原

【Abstract】 A non-contact harmonic magnetic field detection method was proposed for the problem of buried steel pipeline defects no excavation detection. Harmonic excitation signals were constructed by fusing high frequency and low frequency electromagnetic waves based on the principle of frequency modulated carrier wave(FMCW). The space radiation energy and targeting of excitation signal were enhanced by focusing array. A three-dimensional vector tunnel magneto resistance(TMR) differential sensors array was used to record magnetic field signals. The bistable stochastic resonance(SR) algorithm was adopted to enhance the targets signal energy, and the local mean decomposition(LMD) algorithm was used for adaptive time-frequency analysis of the signal. The simulation and laboratory experiment results show that the detection method can extract and identify the defect signals effectively and no excavation detection of buried pipeline damage is realized.更多还原