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"Smart" ultrasonic pig design and its signal processing research

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Journal of Harbin institute of Technology(New Series) 2008年第1期15卷 65-70页

作者：雷华明阙沛文 institute of automatic detection Shanghai Jiaotong University

This paper introduces the design and development of intelligent ultrasonic ＂pig＂ used for seabed pipeline inspection. The data acquisition system （DAS） and the signal processing method are presented. The DAS was designed using a muhi-DSP based structure. The signal processing method adopted a well-enhanced split-spectrum processing （SSP） based on weighting algorithm according to statistical times, which was the statistical distribution of the discrete signals selected by the minimization algorithm. Furthermore, the data compressing method was discussed. It assures the mass data to be processed and compressed in real-time. The effectiveness of the method was proved by laboratory experiments. The research provides an excellent base for further development of the ultrasonic pig.

关键词： intelligent ultrasonic pig seabed pipeline inspection split-spectrum processing muhi-DSP datacompressing

Coefficients de-noising with wavelet transform for magnetic flux leakage data obtained from oil pipeline

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High Technology Letters 2005年第4期11卷 406-409页

作者：韩文花 Que Peiwen institute of automatic detection Shanghai Jiaotong University Shanghai 200030 P.R. China

This paper considers the problem of noise cancellation for the magnetic flux leakage (MFL) data obtained from the inspection of oil pipelines. MFL data is contaminated by various sources of noise, and the noise can considerably reduce the detectability of flaw signals in MFL data. This paper presents a new de-noising approach for removing the system noise contained in the MFL data by using the coefficients de-noising with wavelet transform. Experimental results are presented to demonstrate the advantages of this de-noising approach over the conventional wavelet de-noising method.

关键词： magnetic flux leakage coefficients de-noising wavelet transform pipeline inspection system noise flaw signals

Inspection of pipeline girth welds with ultrasonic phased array technique

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High Technology Letters 2005年第3期11卷 240-244页

作者： Huang Jing（黄晶） Que Peiwen Jin Jianhua institute of automatic detection Shanghai Jiaotong University Shanghai 200030 P.R. China

A novel automatic ultrasonic system used for the inspection of pipeline girth welds is developed, in which a linear phased array transducer using electronic scan is adopted. Optimal array parameters are determined based on a mathematical model of acoustic field for linear phased army derived from Huygens＇ principle. The testing method and the system structure are introduced. The experimental results show that the phased array transducer system has the same detectability as that of conventional ultrasonic transducer system, but the system architecture can be simplified greatly, and the testing flexibility and the testing speed can be improved greatly.

关键词： linear phased array transducer mathematical model of acoustic field pipeline girth welds defect inspection

Wavelet domain adaptive filtering algorithm for removing the seamless pipe noise contained in the magnetic flux leakage data

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High Technology Letters 2006年第2期12卷 170-174页

作者：韩文花 Que Peiwen institute of automatic detection Shanghai Jiaotong University Shanghai 200030 P.R. China

With the widespread application and fast development of gas and oil pipeline network in China, the pipeline inspection technology has been used more extensively. The magnetic flux leakage （MFL） method has established itself as the most widely used in-line inspection technique for the evaluation of gas and oil pipelines. The MFL data obtained from seamless pipeline inspection is usually contaminated by the seamless pipe noise （SPN）. SPN can in some cases completely mask MFL signals from certain type of defects, and therefore considerably reduces the detectability of the defect signals. In this paper, a new de-noising algorithm called wavelet domain adaptive filtering is proposed for removing the SPN contained in the MFL data. The new algorithm results from combining the wavelet transform with the adaptive filtering technique. Results from application of the proposed algorithm to the MFL data from field tests show that the proposed algorithm has good performance and considerably improves the detectability of the defect signals in the MFL data.

关键词： pipeline inspection magnetic flux leakage data discrete wavelet transform wavelet domain adaptive filtering seamless pipe noise

The radial self-positioning algorithm of intelligent ultrasonic probe array in oil/gas pipeline

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High Technology Letters 2007年第4期13卷 379-382页

作者：宋寿鹏 Que Peiwen institute of automatic detection Shanghai Jiaotong University Shanghai 200030 P.R. China

The working principle of the pipeline intelligent pig and the structure of ultrasonic probe array used to detect defects in oil/gas pipeline are introduced. The effects of the array＇ s radial position in pipe on defect resolution are analyzed. The causes leading to radial positioning error are investigated. An algo- rithm for the radial self-positioning is presented. The experimental results show that the radial self-positioning algorithm can eliminate the array＇ s space position error effectively and improve the defect resolution.

关键词： intelligent ultrasonic probe array defect self-positioning algorithm pipeline

Ultrasonic flaw detection using EMD-based signal processing

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High Technology Letters 2006年第1期12卷 14-17页

作者：毛义梅 Que Peiwen institute of automatic detection Shanghai Jiaotong University Shanghai 200030 P.R. China

The precise detection of flaw echoes buried in backscattefing noise caused by material microstructure is a problem of great importance in uhrasonic non-destructive testing （NDT）. In this work, empirical mode decomposition （EMD） is proposed to deal with ultrasonic signal. A time-frequency filtering method based on EMD is designed to suppress noise and enhance flaw signals. Simulated results are presented, showing that the proposed method has an excellent performance even for a very low signal-to-noise ratio （SNR）. The improvement in flaw detection was experimentally verified using stainless steel pipe sample with artificial flaws.

关键词： empirical mode decomposition ultrasonic NDT time-frequency filtering

A high-performance measurement method for artery intima-media thickness in medical ultrasound images

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Optoelectronics Letters 2010年第6期6卷 469-472页

作者：金晶王艳高欣王祁 Laboratory of detection Technology and automatic Equipment Department of Control Science and EngineeringHarbin Institute of Technology

A high-performance measurement method for the artery intima-media thickness(IMT) in medical ultrasound images is *** scheme mainly consists of two *** first part is the detection process,including adaptive gray stretching for image enhancing,gradient transforming to restrain the over-segmentation,and the watershed algorithm for edge *** intima can be detected automatically and *** second part,combined with regional positioning and boundary fitting stages,is used to measure the *** results show that the proposed scheme can yield a good measurement result,and the calculation time can satisfy the practical requirement.

关键词：测量方法超声图像内膜医学性能厚度中层动脉

Hyperspectral datum classification using kernel method based on mutual information of neighbor bands

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Optoelectronics Letters 2009年第4期5卷 309-312页

作者：张淼沈毅王强 Lab.of detection Technology and automatic Equipment Dept.of Control Science and EngineeringHarbin Institute of Technology

Under the framework of support vector machines,this paper proposes a new kernel method based on neighbor bands mutual information for hyperspectral datum *** algorithm assigns weights to different bands in the kernel function according to the amount of useful information that they contain,which makes the band with more useful informa-tion play more important role in the *** research has shown that the band with greater mutual information between neighbor bands contains more useful information,and hence we use the mutual information of each band and its neighbor bands as the weights of the proposed kernel *** experimental results show that for the support vector machines based on polynomial and radial basis function,after introducing the proposed kernel function,the average accuracy is increased more than 1.2% without using any reference map or increasing much more computational time.

关键词：分类方法互信息高光谱邻居内核带基基准支持向量机

A simple algorithm to calculate the pulsed sound field of a wide-band linear phased array

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Journal of Harbin institute of Technology(New Series) 2006年第4期13卷 427-430页

作者：黄晶阙沛文张志钢雷华明金建华 School of Electronic and Computer Information Engineering Ningbo University of Technology institute of automatic detection Shanghai Jiaotong University

A simple algorithm using an impulse response for a rectangular piston element is discussed. The impulse response of linear phased array is obtained hv stumming the impulse responses of rectangular piston elements with different delay times. The output response of the linear wide-band array is equal to the convolution of impulse response functions with wide-band pulse exeiting signal. Sound field distributions and impulse responses of three kinds of transducers are compared. The results can be used to optimize the parameters of the linear phased array transducers used in uhrasonie imaging in nondestructive testing （NDT）.

关键词： linear phased array ultrasonic transducer impulse response sound field