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Exponential Synchronization of Master-Slave Lur'e systems via Intermittent Time-Delay Feedback control

Communications in Theoretical Physics 2010年第10期 679-686页

作者：王一晶郝建娜左志强 Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and AutomationTianjin University School of Electrical Engineering and Automation Tianjin University Department of Mathematics City University of Hong Kong

This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time *** from the previous methods based on the differential inequality technique, a newapproach is proposed to derive some new exponential synchronization *** restriction that the control widthhas to be larger than the time delay is *** leads to a larger application scope for our ***, notranscendental equation is involved in the obtained result, which reduces the computational *** examples aregiven to validate the theoretical results.

关键词： exponential synchronization intermittent control delayed feedback control Razumikhin stabilitytheory Chua＇s circuits

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An unsupervised grid-based approach for clustering analysis

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Science China(Information Sciences) 2010年第7期53卷 1345-1357页

作者： YUE ShiHong1, WANG JeenShing2, TAO Gao1 & WANG HuaXiang1 1school of Electrical engineering and automation, Tianjin key laboratory of Process measurement and control, Tianjin University, Tianjin 300072, China 2Department of Electrical engineering, National Cheng Kung University, Tainan 701, China 1. School of Electrical Engineering and Automation Tianjin Key Laboratory of Process Measurement and Control Tianjin University Tianjin 300072 China2. Department of Electrical Engineering National Cheng Kung University Tainan 701 China

In recent years, the growing volume of data in numerous clustering tasks has greatly boosted the existing clustering algorithms in dealing with very large datasets. The K-means has been one of the most popular clustering algorithms because of its simplicity and easiness in application, but its effciency and effectiveness for large datasets are often unacceptable. In contrast to the K-means algorithm, most existing grid-clustering algorithms have linear time and space complexities and thus can perform well for large datasets. In this paper, we propose a grid-based partitional algorithm to overcome the drawbacks of the K-means clustering algorithm. This new algorithm is based on two major concepts: 1) maximizing the average density of a group of grids instead of minimizing the minimal square error which is applied in the K-means algorithm, and 2) using grid- clustering algorithms to thoroughly reformulate the object-driven assigning in the K-means algorithm into a new grid-driven assigning. Consequently, our proposed algorithm obtains an average speed-up about 10-100 times faster and produces better partitions than those by the K-means algorithm. Also, compared with the K-means algorithm, our proposed algorithm has ability to partition any dataset when the number of clusters is unknown. The effectiveness of our proposed algorithm has been demonstrated through successfully clustering datasets with different features in comparison with the other three typical clustering algorithms besides the K-means algorithm.

关键词： clustering grid-based algorithm K-means algorithm

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Sensorless control for brushless DC motors using adaptive sliding mode observer

Sensorless control for brushless DC motors using adaptive sl...

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作者： Shi, Tingna Lu, Na Li, Wenshan School of Electrical Engineering and Automation Tianjin Key Laboratory Process Measurement and Control Tianjin University Tianjin 300072 China

ISBN: (纸本)9787894631046

An adaptive sliding mode speed and position observer for sensorless control of brushless DC motor (BLDCM) is proposed in this paper. According the mathematical model of BLDCM, the sliding surface was defined based on the errors between actual and estimated currents. Equivalent control and model reference adaptive control (MRAC) is used to obtain position and speed signals of the rotor. The Lyapunov theory is introduced to prove the convergence of this system. A sensorless control system for BLDCM based on the sliding mode observer is implemented. The stability of this observer which shows good robustness is not influenced by both load disturbance and measurement noise. The result of simulation shows that the proposed method can correctly estimate the speed and position of the rotor, and the system has good dynamic and static perf ormances.

关键词： Brushless DC motors

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Single source current drive patterns for electrical impedance tomography

Single source current drive patterns for electrical impedanc...

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2010 IEEE International Instrumentation and measurement Technology Conference, I2MTC 2010

作者： Zhang, Lifeng Wang, Huaxiang Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin China Department of Automation North China Electric Power University Baoding China

ISBN: (纸本)9781424428335

Electrical impedance tomography (EIT) is a technique for reconstructing conductivity of an inhomogeneous medium by injecting currents at the boundary of an object and measuring the resulting changes in voltage. The SNR of acquisitive data and the reconstructed image quality of EIT system are directly determined by current drive patterns. In this paper, eight current drive patterns with the same boundary voltage measurement strategy have been studied. The isopotential lines, the number of independent measurements, measured voltage dynamic range, voltage change with conductivity change and reconstructed image quality of these patterns are compared, through which an optimal current drive pattern was obtained. © 2010 IEEE.

关键词： Image reconstruction

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Physical pictures and performance analysis of wireless power transfer via evanescent fields

Physical pictures and performance analysis of wireless power...

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International Conference on Electrical and control engineering, ICECE 2010

作者： Zhang, Hongyan Yao, Yanping Geng, Zheng Fan, Qiongjian Key Laboratory of Complex Systems and Intelligence Science Institute of Automation CAS Beijing 100190 China School of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

ISBN: (纸本)9780769540313

We present herein for the first time the physical pictures of wireless power transfer via evanescent fields. Our results show that the evanescent fields store energy in a localized domain and can exchange energy between two modes through evanescent waves. We also show that the energy transfer efficiencies can be greatly improved when long-tailed slowly-evanescent fields are adopted. We investigated the energy transfer efficiency and performance of wireless power transfer systems in detail and established their relationship with respect to the coupling strength and the output load parameters. Our theoretical analysis and computer simulations show that the work, radiation and absorption efficiencies are monotone functions of the coupling strength for a given output load parameter and there exists a global optimal output load configuration and a global optimal transfer rate for a fixed coupling strength parameter. The effectiveness, robustness and safety of this class of systems are also verified via the derivation of asymptotic behaviors of the optimum solutions. © 2010 IEEE.

关键词： Evanescent fields

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Robust Exponential Admissibility of Uncertain Switched Singular Time-delay systems

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自动化学报 2010年第12期36卷 1773-1779页

作者： LIN Jin-Xing FEI Shu-Min Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of EducationSoutheast UniversityNanjing 210096P.R.China College of Automation Nanjing University of Posts and TelecommunicationsNanjing 210003P.R.China

This paper investigates the problem of robust exponential admissibility for a class of continuous-time uncertain switched singular systems with interval time-varying delay. By defining a properly constructed decay-rate-dependent Lyapunov function and the average dwell time approach, a delay-range-dependent sufficient condition is derived for the nominal system to be regular, impulse free, and exponentially stable. This condition is also extended to uncertain case. The obtained results provide a solution to one of the basic problems in continuous-time switched singular time-delay systems, that is, to identify a switching signal for which the switched singular time-delay system is regular, impulse free, and exponentially stable. Numerical examples are given to demonstrate the effectiveness of the obtained results.

关键词：自动化系统自动信息函数开关

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Hailstone detection based on time series association rules

Hailstone detection based on time series association rules

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2010 7th International Conference on Fuzzy systems and Knowledge Discovery, FSKD 2010

作者： Lu, Zhiying Zhang, Huan Ma, Hongmin Jia, Huizhen School of Electrical Engineering and Automation Tianjin Key Laboratory of Process Measurement and Control Tianjin University Tianjin 300072 China Tianjin Meteorological Bureau Tianjin 300074 China

ISBN: (纸本)9781424459346

Hailstone is one of main meteorological disasters and it is difficult to forecast effectively. In this paper, a new hail echo detection method based on time series association rules was proposed and a hail echo automatic detection system was built. Compared to the existing methods, the test results have shown that this method eliminated hail alert failure completely and also reduced the proportion of false alarm, raising the accuracy of hail forecast. The system was able to assist forecasters to make correct hail forecasts and provide reference to other disastrous weather forecast. ©2010 IEEE.

关键词： Weather forecasting

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Installation effects of ultrasonic flowmeter in single bend pipe

Installation effects of ultrasonic flowmeter in single bend ...

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15th International Flow measurement Conference 2010, FLOMEKO 2010

作者： Zheng, Dan-Dan Zhang, Tao Sun, Li-Jun Meng, Tao Hu, He-Ming Wang, Chi Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China National Institute of Metrology of China Beijing 100013 China

ISBN: (纸本)9781617824722

The downstream flow of 90° single bend was investigated by computational fluid dynamics (CFD). An acoustic transit time flowmeter was exposed to the downstream flow at various positions. measurement errors with different meter configurations and effects of pipe wall roughness were discussed. Numerical simulation results of three diameter pipes 0.1m, 1m and 10m with increasing the roughness from 0 to 1mm were presented within Reynolds number (Re) range from 5× 103 to 5×106. Copyright © FLOMEKO 2010.

关键词： Flow measurement

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Moving Character Observation of Bubble Rising in Vertical Gas‐Liquid Two‐Phase Flow

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AIP Conference Proceedings 2010年第1期1207卷 604-609页

作者： H. Y. Wang F. Dong aTianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University China

The study of bubble motion in water is a basic subject in gas‐liquid two‐phase flow research. A suit of visualized experimental device was designed and set up. Bubble rising in stagnant liquid in a vertical translucent rectangular tank was studied using the high‐speed video system combined with digital image process methods. Several bubble parameters were calculated base on the processed images. Bubble track, bubble velocity curve and accelerating curve have been plotted at different working situation. The movement of bubble rising in water was observed. And the dynamics of bubble were summarized with experimental analyzing. Both gas orifice diameter and bubble detachment are mainly influencing factor for bubble size and bubble dynamics.

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New type of adaptive control for a class of distributed time-delay systems with adaptation regard to delay parameter

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Journal of systems engineering and Electronics 2010年第6期000卷 1054-1062页

作者： Lin Chai Shumin Fei Haiyan Jin Ruimin Wang Yanhong Li Key Laboratory of Measurement and Control of Complex Systems of Engineering Southeast UniversityNanjing 210096P.R.China School of Automation Southeast UniversityNanjing 210096P.R.China

The problem on stabilization for the system with distributed delays is researched. The distributed time-delay under consideration is assumed to be a constant time-delay, but not known exactly. A design method is proposed for a memory proportional and integral (PI) feedback controller with adaptation to distributed time-delay. The feedback controller with memory simultaneously contains the current state and the past distributed information of the addressed systems. The design for adaptation law to distributed delay is very concise. The controller can be derived by solving a set of linear matrix inequalities (LMIs). Two numerical examples are given to illustrate the effectiveness of the design method.

关键词： distributed delay linear matrix inequality (LMI) adaptive control time-delay systems memory PI feedback

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