共查询到16条相似文献,搜索用时 203 毫秒
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储罐底板的漏磁检测信号处理中小波奇异性检测理论的应用 总被引:1,自引:0,他引:1
漏磁检测是无损检测中的一种重要方式,采用漏磁法采集到的漏磁信号具有数据量大和附带有大量的噪声的特性,其中,缺陷通常表现为输出信号发生突变,因此考察信号突变点的变化对漏磁检测有很重要的意义。本文利用了小波分析其独特的时域和频域特性,分析了基于小波变换的漏磁信号奇异点的定位方法和奇异性程度的计算方法,对漏磁信号进行处理,使信号便于存储和分析,仿真结果表明该方法是有效的。 相似文献
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Corrosion, stresses and mechanical damage of oil and gas pipelines can result in catastrophic failures, so pipeline safety evaluation is an important problem of oil and gas transmission. To evaluate the pipeline safety, this paper described a novel magnetic flux leakage (MFL) inspection device, and the designing MFL intelligent inspection pig was used to multi-radius pipelines and variational work condition. At the same time, because signal processing and defect recognition technique is one of the most important techniques in offshore pipeline inspection MFL system, the paper also discussed its signal processing procedure. Time-frequency analysis, median and adaptive filter, and interpolation processing are adopted to preprocess MFL inspection signal. In order to obtain high sensitivity and precision, we adopted multi-sensor data fusion technique. A wavelet basis function neural network was used to recognize defect parameters. The main contribution of the article is that we presented a novel method to evaluate and predict oil pipelines’ condition through combining neural network, data fusion and expert system techniques, and through constructing a knowledge-based off-line inspection expert system, the system improved its defect recognition capability greatly. 相似文献
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The parts ofgun often create crack when used for aperiod, in order to avoid accident caused by crack, wem ustdetect it periodically, this is very im portant for thesafely operation and the safety of the operator. Them agnetic flux leakage (M FL) detecting m ethod is verysensitive to the crack on ferrom agnetic m aterials, andwith low cost and sim ple arts and crafts. So it is verywidely used in the crack detection for gun.The principle of M FL non-destruction is as follow s.The gun ' s part… 相似文献
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在管道漏磁检测中,缺陷的定量识别一直是个难题,运用有限元分析的方法,建立了漏磁场的数学模型,然后采用有限元分析软件ANSYS建立了漏磁检测装置分析的模型,并进行了二维静态情况的仿真,获得了不同缺陷所产生的漏磁信号,并把这些结果和实验结果进行了比较分析;从这些结果中可以得出了缺陷的特征与其所产生的漏磁信号的特征之间的对应关系,采用仿真的方法来研究漏磁信号的定量识别问题并取得较好的识别效果。 相似文献
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《Sensors and actuators. A, Physical》2006,125(2):186-191
Magnetic flux leakage (MFL) techniques have been widely used for non-intrusively inspecting steel installations by applying magnetization. In the situations where defects may take place on the near and far surfaces of the structure under inspection, current MFL techniques are unable to determine their approximate size. Consequently, an extra transducer may have to be included to provide the extra information required. This paper presents a new approach termed as pulsed magnetic flux leakage (PMFL) for crack detection and characterisation. The probe design and method are introduced. The signal features in time–frequency domains are investigated through theoretical simulations and experiments. The results show that the technique can potentially provide additional information about the defects. Lastly, potential applications are suggested. 相似文献