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Gearbox fault diagnosis of rolling mills using multiwavelet sliding window neighboring coefficient denoising and optimal blind deconvolution

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Science China(Technological Sciences) 2009年第10期52卷 2801-2809页

作者： YUAN Jing HE ZhengJia ZI YanYang LIU Han State Key Laboratory for Manufacturing Systems Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China Shanghai Baosteel Industry Inspection Corporation Baosteel Group CorporationShanghai 200122China

fault diagnosis of rolling mills, especially the main drive gearbox, is of great importance to the high quality products and long-term safe operation. However, the useful fault information is usually submerged in heavy background noise under the severe condition. Thereby, a novel method based on multiwavelet sliding window neighboring coefficient denoising and optimal blind deconvolution is proposed for gearbox fault diagnosis in rolling mills. The emerging multiwavelets can seize the important signal processing properties simultaneously. Owing to the multiple scaling and wavelet basis functions, they have the supreme possibility of matching various features. Due to the periodicity of gearbox signals, sliding window is recommended to conduct local threshold denoising, so as to avoid the "overkill" of conventional universal thresholding techniques. Meanwhile, neighboring coefficient denoising, considering the correlation of the coefficients, is introduced to effectively process the noisy signals in every sliding window. Thus, multiwavelet sliding window neighboring coefficient denoising not only can perform excellent fault extraction, but also accords with the essence of gearbox fault features. On the other hand, optimal blind deconvolution is carried out to highlight the denoised features for operators' easy identification. The filter length is vital for the effective and meaningful results. Hence, the foremost filter length selection based on the kurtosis is discussed in order to full benefits of this technique. The new method is applied to two gearbox fault diagnostic cases of hot strip finishing mills, compared with multiwavelet and scalar wavelet methods with/without optimal blind deconvolution. The results show that it could enhance the ability of fault detection for the main drive gearboxes.

关键词： multiwavelet denoising blind deconvolution gearbox fault diagnosis rolling mill

A seismic gap on the Anninghe fault in western Sichuan, China

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Science China Earth Sciences 2008年第10期51卷 1375-1387页

作者： XueZe Wen Jun Fan GuiXi Yi YiWei Deng Feng Long Institute of Earthquake Science China Earthquake Administration Beijing 100036 China College of Information Engineering Chengdu University of Technology Chengdu 610059 China Present address: Earthquake Administration of Sichuan Provinc

Through integrated analyses of time-varying patterns of regional seismicity, occurrence background of strong and large historical earthquakes along active faults, and temporal-spatial distribution of accu- rately relocated hypocenters of modern small earthquakes, this paper analyzes and discusses the im- plication of a 30-year-lasting seismic quiescence in the region along and surrounding the Anninghe and Zemuhe faults in western Sichuan, China. It suggests that the seismic quiescence for ML≥4.0 events has been lasting in the studied region since January, 1977, along with the formation and evaluation of a seismic gap of the second kind, the Anninghe seismic gap. The Anninghe seismic gap has the background of a seismic gap of the first kind along the Anninghe fault, and has resulted from evident fault-locking and strain-accumulating along the fault during the last 30 years. Now, two fault sections either without or with less small earthquakes exist along the Anninghe fault within the An- ninghe seismic gap. They indicate two linked and locked fault-sections, the northern Mianning section and the Mianning-Xichang section with lengths of 65 km and 75 km and elapsed time from the latest large earthquakes of 527 and 471 years, respectively. Along the Anninghe fault, characteristics of both the background of the first kind seismic gap and the seismicity patterns of the second seismic gap, as well as the hypocenter depth distribution of modern small earthquakes are comparable, respectively, to those appearing before the M=8.1 Hoh Xil earthquake of 2001 and to those emerging in the 20 years before the M=7.1 Loma Prieta, California, earthquake of 1989, suggesting that the Anninghe seismic gap is tending to become mature, and hence its mid- to long-term potential of large earthquakes should be noticeable. The probable maximum magnitudes of the potential earthquakes are estimated to be as large as 7.4 for both the two locked sections of the Anninghe fault.

关键词： Anninghe fault seismic quiescence seismic gap fault locking seismic potential

Experimental investigation of three-dimensional propagation process from surface fault

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Science China Earth Sciences 2008年第10期51卷 1426-1435页

作者： LIU LiQiang LIU PeiXun WONG HonChu MA ShaoPeng GUO YanShuang State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China Department of Civil and Structural Engineering The Hong Kong Polytechnic UniversityHong KongChina Department of Mechanics School of ScienceBeijing Institute of TechnologyBeijing 100083China

Experimental study of the formation and propagation of three-dimensional (3D) faults is of great sig- nificance in the understanding of the propagation process developing from initial natural faults. In the study described in this paper, experimental investigations of 3D propagation processes of a type of surface fault are carried out under biaxial compression. The strain field near the surface fault is dy- namically measured and fully analyzed with a high-density Multi-Channel Digital Strain Gauge (MCDSG) and Digital Speckle Correlation Method (DSCM) based on the white-light image analysis. Simultane- ously the micro-fracture process involved in fault formation is observed by a 3D acoustic emission (AE) location system with a set of multi-channel whole-wave record equipment. The experimental results show that the 3D propagation process of surface fault differs greatly from that of the two-dimensional (2D) state and that a new more complicated type of 3D morphological characters and deformation mechanisms are produced. The 3D propagation process of surface faults may be divided into three stages: 1) the first stage of crack propagation initiated by wing cracks; 2) the conversion stage propa- gated by petal cracks; and 3) the second stage of crack propagation formed by shell-shaped fracture surface. The primary propagation patterns of the three stages are different. The corresponding defor- mation fields and micro-fracture distributions are likewise different. The fracture activities from petal cracks especially are of vital importance during surface fault propagation. This is also a key conversion state and marks an intrinsic difference between 2D-like and the 3D state in fault development.

关键词： surface fault 3D propagation strain field digital speckle acoustic emission

Estimation of the current stress field and fault reactivation analysis in the Asmari reservoir, SW Iran

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Petroleum Science 2019年第3期16卷 513-526页

作者： Majid Taghipour Mohammad Ghafoori Gholam Reza Lashkaripour Nasser Hafezi Moghaddas Abdullah Molaghab Department of Geology Faculty of ScienceFerdowsi University of Mashhad MashhadIran National Iranian South Oil Company (NISOC) AhwazIran

Knowing the current condition of the faults and fractures in a reservoir is crucial for production and injection activities.A good estimation of the fault reactivation potential in the current stress field is a useful tool for locating the appropriate spot to drill injection wells and to calculate the maximum sustainable pore pressure in enhanced oil recovery and geosequestration *** this study,after specifying the current stress state in the Gachsaran oilfield based on Anderson’s faulting theory,the reactivation tendency of four faults(F1,F2,F3,and F4)in the Asmari reservoir is analyzed using 3D Mohr diagrams and slip tendency *** showed that all the faults are stable in the current stress state,and F2 has the potential to undergo the highest pore pressure build-up in the *** the other hand,F3 has the proper conditions(i.e.,strike and dip referring to σHmax orientation)for *** polygons were also applied to show the effect of the pore pressure increase on fault stability,in a graphical *** to the results,the best location for drilling a new injection well in this part of the field is the NW side of F2,due to the lower risk of *** was found that both methods of 3D Mohr diagrams and slip tendency factors predict similar results,and with the lack of image logs for stress orientation determination,the slip tendency method can be *** results of such studies can also be used for locating safe injection points and determining the injection pressure prior to numerical modeling in further geomechanical studies.

关键词： Asmari reservoir fault reactivation 3D Mohr diagram Slip tendency Normal faulting regime

Characteristics of mantle degassing and deep-seated geological structures in different typical fault zones of China

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Science China Earth Sciences 2005年第7期48卷 1074-1088页

作者： TAO Mingxin1,2, XU Yongchang1, SHI Baoguang1, JIANG Zhongti3, SHEN Ping1, LI Xiaobin1 & SUN Mingliang1 1. Key Laboratory of Gas Geochemistry, Lanzhou Institute of Geology, Chinese Academy of Sciences, Lanzhou 730000, China 2. Beijing Normal University, Beijing 100875, China 3. The Practical Geologic Data Center, State Land Resource Department, Sanhe 065201, China Key Laboratory of Gas Geochemistry Lanzhou Institute of Geology Chinese Academy of Sciences Lanzhou 730000 China Beijing Normal University Beijing 100875 China Practical Geologic Data Center State Land Resource Department Sanhe 065201 China

In this paper a comprehensive tracing study is conducted on mantle degassing and deep-seated geological structures in different types of fault zones in the continent of China based on the helium isotope data, coupled with some indices such as CO2/3He, CH4/3He and 40Ar/36Ar, and geological tectonics data. There are four representative types of fault zones: (1) Lithospheric fault zones in the extensional tectonic environment are characterized by a small Earth’s crust thickness, a lower CH4/3He-high R and lower CO2/3He-high R system, the strongest mantle de- gassing, and the dominance of mantle fluid, as is represented by the Tancheng-Lujiang fault zone. (2) The lithospheric fault zones or the subduction zone in the strongly compresso-tectonic envi- ronment, for instance, the Bangonghu-Nujiang fault zone, are characterized by a huge thick Earth’s crust, with the R/Ra values within the range of 0.43―1.13, and weak mantle degassing with mantle-source helium accounting for 5%―14% of the total. (3) The deep-seated fault zones at the basinal margins of an orogenic belt are characterized by R values being on order of mag- nitude of 10?7, and the CH4/3He values, 109―1010, CO2/3He values, 106―108; as well as much weak mantle degassing. (4) The crustal fault zones in the orogenic belt, such as the Yaojie fault zone (F19), possess a high CH4/3He-low R (10?8) and high CO2/3He-low R system, with no obvi- ous sign of mantle degassing. Studies have shown that the deep-seated huge fault zones are the major channel ways for mantle degassing, the main factors controlling the intensity of mantle degassing are fault depth, tectonic environment and crust thickness; the intensity of mantle de- gassing can reflect the depth and the status of deep-seated tectonic environment of fault, while the geochemical tracing studies of gases can open up a new research approach; upwelling ac- tivity of hydrothermal fluids from the deep interior of the Earth may be one of the driving forces for the forma

关键词： fault zone mantle degassing deep-seated structure 3He/He CO2/3He CH4/3He.

Tectonic implication of geomorphometric analyses along the Saravan fault: evidence of a difference in tectonic movements between the Sistan Suture Zone and Makran Mountain Belt

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Journal of Mountain Science 2019年第5期16卷 1023-1034页

作者： Roghayeh KASHANI Abdolreza PARTABIAN Ahmad NOURBAKHSH Department of Geology College of Sciences University of Sistan and Baluchestan Department of Earth Sciences College of Sciences Shiraz University

In this paper, remote sensing techniques,as well as field studies, have been used to investigate the geomorphological processes and landscape evolution along the Saravan fault, SE Iran to highlight how topographic features were influenced by active tectonics. Quantitative geomorphic analysis was carried out using mountain-front sinuosity(Smf),valley floor width-valley height ratio(Vf), drainage basin asymmetry factor(Af), Hypsometric integral(Hi), drainage basin shape index(Bs), mean axial slope of channel(MASC), standard deviation of topography(STD) and index of active tectonic(Iat).Remote sensing techniques, as well as field studies revealed that the Saravan fault have three parts trending N-S, NW-SE, and E-W. Obtained results show that basins with high Iat index are located at where the strike of the Saravan faults changes and where several strike-slip faults are crossed the Saravan fault.

关键词： Active Tectonic Sistan Suture Zone Makran Mountain Belt Saravan fault Iran DEM

Parallel resonance type fault current limiting circuit breaker

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High Voltage 2020年第1期5卷 76-82页

作者： Hamid Radmanesh Seyed Hamid Fathi Electrical Engineering Department Shahid Sattari Aeronautical University of Science and TechnologyTehranIran Electrical Engineering Department Amirkabir University of TechnologyTehranIran

The main goal of this study is introducing a novel fault current limiter based on parallel resonance structure(PRFCL)for high voltage *** normal mode,the PRFCL reactor is short-circuited via a rectifier bridge DC output voltage and LC resonance tank shows negligible impedance in the *** a fault,the rectifier bridge switches are turned off,so that the parallel resonance LC tank connects to the line with high *** impedance of the resonance structure can limit the fault current,*** is shown that the suggested PRFCL can act as a breaker and opens the line during the fault *** order to show the suggested PRFCL abilities,MATLAB software is used to simulate the normal and fault *** addition,a scale-down prototype is implemented to confirm the simulation *** comparative study shows that PRFCL has acceptable performance in normal and current limiting operation modes.

关键词： period fault limiting

GPS monitoring of temporal deformation of the Xianshuihe fault

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Science China Earth Sciences 2008年第9期51卷 1259-1266页

作者： TERUYUKI Kato Earthquake Research Institute University of TokyoTokyo Japan

Highly precise (σ ~1 mm) temporal deformation measurements are taken across the Xianshuihe fault from two pairs of continuous GPS stations straddling the fault. Baseline vector changes of the two pairs of stations show clearly the difference in deformation behavior between the Qianning and Daofu segments of the fault: the former deforms steadily, and the latter deforms with a strong transient component. The transient deformation across the Daofu segment is possibly related to its irregular geometry, where the fault splits into two branches, that is, the east and west branches. An attempt is made to interpret the baseline vector changes using a kinematic fault model composed of a brittle layer in the upper crust, a ductile layer in the lower crust, and a transition zone in between. The slip in the transition zone of the south segment of the Xianshuihe fault is steady. The slips in the transition zones of the north and Daofu segments of the Xianshuihe fault, however, are not steady, and the average slip rates there are higher than that of the south segment. The difference in deformation behavior is probably associated with the rheological properties of the fault interface, suggesting that the overall fault strength of the south segment is greater than those of the north and Daofu segments, corresponding to longer earthquake recurrence time.

关键词： Xianshuihe fault GPS deformation field temporal change brittle-ductile transition zone

Sliding Mode fault Tolerant Attitude Control Scheme for Spacecraft with Actuator faults

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Transactions of Nanjing University of Aeronautics and Astronautics 2019年第1期36卷 119-127页

作者： CAO Teng GONG Huajun HAN Bing College of Automation Engineering Nanjing University of Aeronautics and Astronautics

An active fault tolerant control scheme is investigated for the attitude control systems of spacecraft with external disturbance and actuator faults by using the sliding mode technique. Firstly,the dynamic equations and kinematic equations of spacecraft are given. For the dynamic mode of spacecraft in faulty case,a fault diagnosis component is used for fault detection and estimation by using a nonlinear observer. According to the fault estimation information obtained during the fault diagnosis,the fault tolerant control scheme is developed by adopting the backstepping sliding mode control technique. Meanwhile,the Lyapunov theory is used to analyze the stability of the closed-loop attitude systems. Finally,simulation results for the attitude dynamics models show the feasibility of the proposed fault tolerant scheme.

关键词： fault tolerant control fault estimation actuator faults sliding mode control