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Discrete-time sliding mode control for a class of stochastic system

ICIC Express Letters 2013年第7期7卷 2087-2092页

作者： Chang, Ru Fang, Yiming Liu, Le Li, Jianxiong Key Lab of Industrial Computer Control Engineering of Hebei Province Institute of Electrical Engineering Yanshan University No. 438 Hebei Street Qinhuangdao 066004 China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Hebei Street Qinhuangdao 066004 China

This paper is concerned with the discrete-time sliding mode control (SMC) problem for a class of stochastic system. A sufficient condition is presented to ensure the mean-square asymptotic stability of the stochastic system in the sliding mode by solving a linear objective function. Moreover, a power function is introduced to design a novel discrete sliding mode controller. The controller can guarantee the good dynamic quality of the stochastic system, and can ensure the reachability of the discrete-time sliding motion. Finally, a numerical example is given to illustrate the validity of the proposed SMC scheme. © 2013 ICIC International.

关键词： Stochastic systems

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Online extraction of main linear trends for nonlinear time-varying processes

Online extraction of main linear trends for nonlinear time-v...

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作者： Kalhor, Ahmad Araabi, Babak N. Lucas, Caro Control and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering University of Tehran Tehran Iran Tehran Iran

Linear trends of a time-varying process include useful and insight data about its temporal behaviors. In this paper, we introduce an approach for extracting the main linear trends of a nonlinear time-varying process. In this approach, originally, an adaptive linear model is utilized to estimate the temporal-linear trends of the process. Then, by using a suitable distance index, an online clustering algorithm has been developed to classify the estimated linear trends. Considering the mean and the number of members for each cluster, main linear trends are extracted for the process. Through an illustrative example, the methodology of the proposed approach in extracting main linear trends is explained and its capability is shown. Also, through two case studies -electrical load time series and pH neutralization process- the application of the proposed method in studying temporal behaviors of processes like stability, changing rate, oscillation and characteristics of transient states are explained. © 2012 Elsevier Inc. All rights reserved.

关键词： Power quality

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ℋ− adaptive observer design and parameter identification for a class of nonlinear fractional-order systems

ℋ− adaptive observer design and parameter identification f...

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IEEE Conference on Decision and control

作者： Ibrahima N'Doye Holger Voos Taous-Meriem Laleg-Kirati Mohamed Darouach Computer Electrical and Mathematical Sciences and Engineering Division (CEMSE) King Abdullah University of Science and Technology(KAUST) Interdisciplinary Centre for Security Reliability and Trust (SnT) Luxembourg University of Lorraine Research Center for Automatic Control of Nancy (CRAN UMR 7039 CNRS) Cosnes et Romain France

In this paper, an adaptive observer design with parameter identification for a nonlinear system with external perturbations and unknown parameters is proposed. The states of the nonlinear system are estimated by a nonlinear observer and the unknown parameters are also adapted to their values. Sufficient conditions for the stability of the adaptive observer error dynamics are derived in terms of linear matrix inequalities. Simulation results for chaotic Lorenz systems with unknown parameters in the presence of external perturbations are given to illustrate the effectiveness of our proposed approach.

关键词： Observers Equations Chaos Vectors Adaptive systems Linear matrix inequalities

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An extension of distributed dynamic description logics for the representation of heterogeneous mappings

Journal of Software

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Journal of Software 2013年第1期8卷 243-250页

作者： Wang, Zhuxiao Guo, Jing Chen, Fei Wu, Kehe Wang, Peng School of Control and Computer Engineering State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University 102206 Beijing China National Computer Network Emergency Response Technical Team Coordination Center of China 100029 Beijing China School of Control and Computer Engineering North China Electric Power University 102206 Beijing China Institute of Information Engineering Chinese Academy of Sciences 100195 Beijing China

As a family of dynamic description logics, DDL(X) is constructed by embracing actions into the description logic X, where X represents well-studied description logics ranging from the ALC to the SHOIQ. To efficiently support automated interoperability between ontology-based information systems in distributed environments, we have to design an expressive mapping language to semantically understand resources from remote and heterogeneous systems. Distributed Dynamic Description Logics D3L(X) is a natural generalization of the DDL(X) framework, which is designed to model the distributed dynamically-changing knowledge repositories interconnected by semantic mappings and to accomplish reasoning in distributed, heterogeneous environments. In this paper, we propose an extension of Distributed Dynamic Description Logics D3L(X) and investigate the reasoning mechanisms in D3L(X). © 2013 ACADEMY PUBLISHER.

关键词： Interoperability

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Finite Abstractions of Networked control Systems

Finite Abstractions of Networked Control Systems

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IEEE Annual Conference on Decision and control

作者： Majid Zamani Manuel Mazo Alessandro Abate Department of Electrical Engineering and Information Technology Technische Universitat Munchen D-80290 Munich Germany Delft Center for Systems and Control Delft University of Technology 2628 CD Delft The Netherlands Department of Computer Science University of Oxford OX1 3QD Oxford United Kingdom

ISBN: (纸本)9781467360890

In networked control systems (NCS), the communication between sensors, controllers, and actuators is supported by a shared communication channel that is subject to variable communication delays, limited bandwidth, packet losses, quantization errors, and other practical non-idealities. This work investigates the problem of constructively deriving symbolic models of NCS by simultaneously considering the mentioned network non-idealities. By employing the obtained symbolic models, one can completely automate the design of controllers enforcing rich logical specifications, e.g. formulae in linear temporal logic, over NCS.

关键词： Delays Sensors Artificial neural networks Trajectory Actuators

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Detection of abnormalities in wireless capsule endoscopy frames using local fuzzy patterns

Detection of abnormalities in wireless capsule endoscopy fra...

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2013 20th Iranian Conference on Biomedical engineering, ICBME 2013

作者： Maghsoudi, Omid Haji Soltanian-Zadeh, Hamid School of Medical Radiation Engineering Shahid Beheshti University Tehran Iran Control and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering University of Tehran Tehran Iran

ISBN: (纸本)9781479932320

Wireless capsule endoscopy (WCE) is a relatively new technology that captures images of the entire gastrointestinal tract non-invasively and painlessly. A large number of frames are captured during an examination. The main difficulty for physicians is to review the frames visually. In recent years, some methods have been devised to help physicians. Here, a novel method is devised to distinguish among frames whether the frames contain abnormal region or not. This goal is achieved using local fuzzy patterns (LFP) that is compared with rotation invariant local binary patterns (LBP). In addition to this comparison, four color channels (red, hue, green, and gray scale) are examined to find the best one for using LFP. Experimental results indicate that LFP is a powerful method for texture detection, and can develop the LBP results in the WCE frames. © 2013 IEEE.

关键词： Local binary pattern

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A fully automated segmentation of radius bone based on active contour in wrist MRI data set

A fully automated segmentation of radius bone based on activ...

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2013 20th Iranian Conference on Biomedical engineering, ICBME 2013

作者： Yousefi, Hamed Fatehi, Mansoor Amian, Mehdi Zoroofi, Reza A. Control and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering University of Tehran Tehran Iran Iranian Society of Radiology Tehran Iran

ISBN: (纸本)9781479932320

Advanced medical imaging techniques require high performance segmentation algorithms. Extracting the structures of interest accurately is one of the main challenges in medical imaging segmentation. In this paper a methodological approach based on active contour is proposed for fully automated segmentation of radius bone. As soft tissues like tendons, muscles and fat around the bone have close intensities to internal parts of the bone, accurate segmentation is difficult. Here the designed framework takes an MR image including radius bone as input and produces the segmented radius bone in 3D voxel set. The multi-step approach for segmentation is as following. Since our data set was much noisier, at first we denoised and enhanced contrast of the data using wavelet transform. Then an initial segmentation was produced focusing on edge map. Next, according to anatomical knowledge about the radius bone shape and size in intermediate slices, radius bone was extracted in this slice and used as the mask slice for adjacent slices. This masking procedure was applied to all slices with a 3D approach. After that we derived a convex hull region around the radius bone. This step was done for whole slices as regions of interest. Finally the estimated convex region is used as an initial mask for active contour. This framework was tested on more than 600 coronal MR slices of 23 subjects. In comparison to manual segmentation our method showed an average Dice similarity coefficient DSC and kappa statistics of 94.82% and 92.46% respectively. In the future works we utilize the proposed approach as part of a computer-aided diagnosis system for bone age estimation. © 2013 IEEE.

关键词： Wavelet transforms

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Design and experimental implementation of a robust DLQR for three-phase grid-connected converters

Design and experimental implementation of a robust DLQR for ...

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IEEE/IAS International Conference on Industry Applications (INDUSCON)

作者： Luiz Antonio Maccari Claudio Luiz do Amaral Santini Ricardo C. L. F. Oliveira Vinícius Foletto Montagner Power Electronics and Control Research Group - GEPOC Federal University of Santa Maria - UFSM Rio Grande do Sul Brazil Center of Technology - NT Federal University of Rondônia - UNIR Porto Velho Rondônia Brazil School of Electrical and Computer Engineering - FEEC University of Campinas - UNICAMP São Paulo Brazil

This paper deals with the design of robust discrete linear quadratic regulators applied to three-phase inverters connected to the grid by means of LCL filters. The system is modeled in the state space in abc coordinates and changed to aβ coordinates, allowing a simple control design and implementation. Resonant controllers are used to ensure the tracking of sinusoidal references for grid current. The control gains are computed by means of a convex optimization problem and ensure that the closed-loop system is robustly stable when operating under conditions of uncertain grid inductance. The controller is experimentally validated with a 5.4 kW prototype, showing good results for three-phase grid current control.

关键词： Robustness Harmonic analysis Inverters Inductance Resonant frequency Closed loop systems Frequency control

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Improved resampling particle filter for maneuvering point target tracking

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Journal of Applied Sciences 2013年第11期13卷 2045-2050页

作者： Zhou, R. Liu, B. Teng, J. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China School of Control and Computer Engineering North China Electrical Power University Beijing 102206 China University of Chinese Academy of Science Beijing 100049 China

The sample impoverishment during particles resampling is a challenging problem in using particle filter to track point target. The reason is that the impoverishment will lead to the divergence of particles and failure of tracking. To solve the problem, a new resampling algorithm is presented in this study. The idea is that random particle samples are drawn from the neighborhoods of previous samples with high weights according to Gaussian distribution instead of simple duplication. Therefore, during the resampling, the effect of sample impoverishment is reduced and diversity of particle samples is enriched because of the samples expansion while the low weights samples are discarded. To illustrate proposed method, the resampling algorithm with simple duplication and the resampling algorithm with random drawing samples based on Gaussian distribution are compared. Simulation results show that the tracking failure is reduced in the quantitative criteria-RMSE. © 2013 Asian Network for Scientific Information.

关键词： Gaussian distribution

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Safe joint mechanism using passive compliance method for collision safety

Safe joint mechanism using passive compliance method for col...

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2013 1st RSI/ISM International Conference on Robotics and Mechatronics, ICRoM 2013

作者： Zebardast, Omid Moradi, Hadi Najafi, Farshid Department of Mechatronics Engineering University of Tehran International Campus Kish Island Iran Control and Intelligent Processing Center School of Electrical and Computer Engineering University of Tehran Tehran Iran Department of Mechanical Engineering University of Tehran Tehran Iran

ISBN: (纸本)9781467358118

In this paper, the design and implementation of a novel passive safe joint is reported. This safe joint is designed for applications, such as an air hockey playing robot playing against a human, in which the force applied by the linkage should be kept below a certain threshold. The proposed mechanism benefits from the compliance of two ramps controlled by the nonlinear behavior of a spring. The passivity of the design, the small footprint, the low cost of production, and the ability to rotate 360 degrees are the main advantages of this design. The mechanism has been designed, evaluated, implemented and tested showing its effectiveness. Finally it has been incorporated in an air hockey robot showing its capability in action. © 2013 IEEE.

关键词： Sports

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