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Study on flaw identification of ultrasonic signal for large shafts based on optimal support vector machine

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仪器仪表学报 2008年第5期29卷 908-913页

作者： Zhao Xiufen Yin Guofu tian guiyun Yin Ying College of Manufacturing Science and Engineering Sichuan University Chengdu 610065 China School of Electrical Electronic and Computer Engineering University of Newcastle UK

Automatic identification of flaws is very important for ultrasonic nondestructive testing and evaluation of large shaft.A novel automatic defect identification system is *** packet analysis(WPA)was applied to feature extraction of ultrasonic signal,and optimal Support vector machine(SVM)was used to perform the identification ***,comparative study on convergent velocity and classified effect was done among SVM and several improved BP network *** validate the method,some experiments were performed and the results show that the proposed system has very high identification performance for large shafts and the optimal SVM processes better classification performance and spreading potential than BP manual neural network under small study sample condition.

关键词：裂纹鉴别技术超声波转轴支持向量机

Transient-Spatial Pattern Mining of Eddy Current Pulsed Thermography Using Wavelet Transform

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Chinese Journal of Mechanical Engineering 2014年第4期27卷 768-778页

作者： YANG Hailong GAO Bin tian guiyun REN Wenwei WOO Wai Lok School of Automation Engineering University of Electronic Science and Technology of China School of Electrical and Electronic Engineering Newcastle University

Eddy current pulsed thermography（ECPT） is an emerging Non-destructive testing and evaluation（NDT E） technique, which uses hybrid eddy current and thermography NDT E techniques that enhances the detectability from their compensation. Currently, this technique is limited by the manual selection of proper contrast frames and the issue of improving the efficiency of defect detection of complex structure samples remains a challenge. In order to select a specific frame from transient thermal image sequences to maximize the contrast of thermal variation and defect pattern from complex structure samples, an energy driven approach to compute the coefficient energy of wavelet transform is proposed which has the potential of automatically selecting both optimal transient frame and spatial scale for defect detection using ECPT. According to analysis of the variation of different frequency component and the comparison study of the detection performance of different scale and wavelets, the frame at the end of heating phase is automatically selected as an optimal transient frame for defect detection. In addition, the detection capabilities of the complex structure samples can be enhanced through proper spatial scale and wavelet selection. The proposed method has successfully been applied to low speed impact damage detection of carbon fibre reinforced polymer（CFRP） composite as well as providing the guidance to improve the detectability of ECPT technique.

关键词： non-destructive testing and evaluation composite impact damage detection wavelet transform energy driven approach transient-spatial analysis

Current Trends and Perspectives of Detection and Location for Buried Non-Metallic Pipelines

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Chinese Journal of Mechanical Engineering 2021年第5期34卷 118-146页

作者： Liang Ge Changpeng Zhang guiyun tian Xiaoting Xiao Junaid Ahmed Guohui Wei Ze Hu Ju Xiang Mark Robinson School of Mechanical and Electrical Engineering Southwest Petroleum UniversityChengdu 610500China School of Engineering Newcastle UniversityNewcastle NE17RUUK School of Electrical Information Southwest Petroleum UniversityChengdu 610500China Electrical Department Sukkur IBA UniversitySukkur 65200Pakistan School of Science Southwest Petroleum UniversityChengdu 610500China

Buried pipelines are an essential component of the urban infrastructure of modern *** buried pipes are mainly made of metal *** the development of material science and technology in recent years,non-metallic pipes,such as plastic pipes,ceramic pipes,and concrete pipes,are increasingly taking the place of pipes made from metal in various pipeline networks such as water supply,drainage,heat,industry,oil,and *** location technologies for the location of the buried metal pipeline have become mature,but detection and location technologies for the non-metallic pipelines are still *** this paper,current trends and future perspectives of detection and location of buried non-metallic pipelines are ***,this paper reviews and analyzes electromagnetic induction technologies,electromagnetic wave technologies,and other physics-based *** then focuses on acoustic detection and location technologies,and finally introduces emerging *** the technical characteristics of each detection and location method have been compared,with their strengths and weaknesses *** current trends and future perspectives of each buried non-metallic pipeline detection and location technology have also been ***,some suggestions for the future development of buried non-metallic pipeline detection and location technologies are provided.

关键词： Non-metallic pipeline Pipeline detection and location Non-destructive test and evaluation Acoustic technologies

Network coding with diversity and outdated channel state information

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Journal of Modern Transportation 2012年第4期20卷 261-267页

作者： Tong CHEN Kanapathippillai CUMANAN Zhiguo DING guiyun tian School of Electrical & Electronic Engineering Newcastle University

Physical-layer network coding （PNC） has the potential to significantly improve the throughput of wireless networks where the channels can be modeled as additive white Gaussian noise （AWGN） channel. As extending to mul- tiple channels, this technique requires both amplitude and phase compensation at each transmitter and will lead to inef- ficient systems yielding no diversity even with perfect channel state information （CSI）. In order to avoid these limita- tions, we apply network coding with diversity （NCD） to achieve a form of selection diversity and extend NCD to coop- erative multiple access channels in this paper. However, in practical wireless communication systems, the CSI could become outdated due to the difference between the CSI used in the relay selection and data transmission phases. Hence, the selected relay may not be the best one during data transmission phase due to the dynamic change in the wireless channels. Therefore, we first explore the relation between the present and past CSIs. Exploiting this relationship, the NCD scheme with outdated CSI is investigated based on the past CSI. To evaluate the performance of this scheme, an information-theoretic metric, namely the outage capacity, is studied under this condition.

关键词： network coding with diversity (NCD) cooperative multiple access channels channel state information (CSI)

A static and dynamic factorscoupled forecasting model of regional rainfall-induced landslides:A case study of Shenzhen

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Science China(Technological Sciences) 2008年第S2期51卷 164-175页

作者： JIA guiyun,tian Yuan,LIU Yu & ZHANG Yi Institute of Remote Sensing and GIS,Peking University,Beijing 100871,China Institute of Remote Sensing and GIS Peking University Beijing China

Most rainfall-induced landslide forecasting models focus on the relation between landslides and rainfall,which is one of the dynamic factors,and seldom consider the stacitc factors,such as geological and geograpical *** susceptibility,however,is determinded by both static and dynamic *** article proposes a static and dynamic factors-coupled forecasting model(SDFCFM) of regional rainfall-induced landslides,which quantitatively considers both the static and dynamic factors that affect *** generalized additive model(GAM) is applied to coupling both factors to get the landslide *** the case study,SDFCFM is applied to forecast the landslide occurrences in Shenzhen during a rainfall process in *** with the rainfall logistic regression model,the resulting landslide susceptibility map illustrates that SDFCFM can reduce the forecast redundancy and improve the hit *** is both applicable and *** application of SDFCFM in landslide warning and prevention system will improve its efficiency and also cut down the cost of human and matreial resources.

关键词： regional rainfall-induced landslides static and dynamic factors-coupled forcasting model(SDFCFM) generalized additive model(GAM) landslide susceptibility

Pulsed electromagnetic non-destructive evaluation and applications

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Instrumentation 2014年第1期1卷 15-28页

作者： tian guiyun ZHOU Xiuyun Ibukun D.Adewale School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731China School of Electrical and Electronic Engineering Newcastle UniversityNewcastle upon TyneNE17RUUnited Kingdom.

This paper introduces recent research work in the field of pulsed electromagnetic non-destructive testing/*** are pulsed eddy current,pulsed magnetic flux leakage and eddy current pulsed *** paper introduces pulsed electromagnetic techniques and their different case studies on defect detection as well as stress *** tests have been validated and future research plans are *** paper demonstrates pulsed electromagnetic non-destructive testing and evaluation for not only depth information,but also for multiple parameter measurement and multiple integration,which are important for future development.

关键词： electromagnetic pulsed eddy current pulsed magnetic flux leakage eddy current pulsed thermography defects non-destructive testing/evaluation(NDT&E).

无源无线射频识别传感器及其在结构健康监测中的应用

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南京航空航天大学学报 2017年第4期49卷 453-460页

作者：田贵云张俊孟召宗南京航空航天大学自动化学院电子科技大学自动化工程学院广东工业大学信息工程学院英国南安普顿大学工程与环境学院

针对无损检测与结构健康监测技术的发展趋势与挑战,介绍了一种无源无线射频识别(Radio frequency identification,RFID)监测传感器,并揭示了其在结构健康监测,特别是在航空航天领域的潜在应用。然后,从传感机制、信号测量、特征分析与... 详细信息

针对无损检测与结构健康监测技术的发展趋势与挑战,介绍了一种无源无线射频识别(Radio frequency identification,RFID)监测传感器,并揭示了其在结构健康监测,特别是在航空航天领域的潜在应用。然后,从传感机制、信号测量、特征分析与提取等多角度对RFID传感技术在结构健康监测领域应用和存在的问题进行了全面阐述。最后,对RFID传感技术的发展前景和研究方向做了展望。本文为RFID传感技术在结构健康监测领域的研究和应用提供了理论指导和设计依据。

关键词：射频识别无源无线传感器无损检测结构健康监测裂纹

基于Hilbert变换的激光超声波成像技术在缺陷检测中的应用

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中国激光 2014年第5期41卷 182-188页

作者：曾伟王海涛田贵云方凌汪文南京航空航天大学自动化学院江苏南京210016 纽卡斯尔大学电气与电子工程学院

介绍了一种基于Hilbert变换的激光超声波传播图像方法,通过采用脉冲激光器在被测材料表面产生超声波信号,对接收的超声波信号进行Hilbert变换,并详细分析了超声波信号在被检测材料表面传播的时域波形图,最后利用超声波成像技术将超声波... 详细信息

介绍了一种基于Hilbert变换的激光超声波传播图像方法,通过采用脉冲激光器在被测材料表面产生超声波信号,对接收的超声波信号进行Hilbert变换,并详细分析了超声波信号在被检测材料表面传播的时域波形图,最后利用超声波成像技术将超声波信号在被测材料的传播过程进行图像显示。实验结果表明:采取Hilbert对超声波信号进行变换的方法不仅能有效地提取超声波信号在缺陷处传播的信息,还能从超声波传播的图像中直观、高效地检测出表面缺陷的形状、大小及分布情况。因此,提出的Hilbert变换的激光超声波成像技术为工业中缺陷的定量检测提供了方法。

关键词：激光技术 Hilbert变换激光超声波脉冲激光器表面缺陷定量检测

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电磁声谐振对Q235钢压缩形变评价研究

仪器仪表学报 2019年第5期40卷 153-160页

作者：蔡智超陈澜赵振勇田贵云华东交通大学电气与自动化工程学院南昌330013 英国纽卡斯尔大学工程学院纽卡斯尔NE17RU

结构件塑性变形检测是设备安全运维中值得注意的重要问题。针对常见的Q235钢材料塑性变形问题,提出了一种基于电磁换能器谐振模式的非接触超声检测的方法。有别于传统的超声回波反射时差法测距原理,共振所产生的谐振超声能够显著增强电... 详细信息

结构件塑性变形检测是设备安全运维中值得注意的重要问题。针对常见的Q235钢材料塑性变形问题,提出了一种基于电磁换能器谐振模式的非接触超声检测的方法。有别于传统的超声回波反射时差法测距原理,共振所产生的谐振超声能够显著增强电磁声谐振点的声波幅值,利用超声波在试件内共振方式实现更高精确的厚度检测。通过双波压缩叠加法及双波压缩叠乘法能够有效改善电磁声谐振信噪比并实现谐振点的提取。通过对标准试件的厚度测量,其厚度测量绝对误差控制在0.2%以下,最后利用电磁声谐振实现对不同轴向压力载荷下Q235试件的形变测量。

关键词：塑性形变无损检测电磁声谐振