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$\mathcal{L}_{2}$-Gain Analysis for a Class of Hybrid systems With Applications to Reset and Event-Triggered Control: A Lifting Approach

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IEEE Transactions on Automatic Control 2016年第10期61卷 2766-2781页

作者： W. P. M. H. Heemels G. E. Dullerud A. R. Teel Control System Technology Group Department of Mechanical Engineering Eindhoven University of Technology Eindhoven The Netherlands Mechanical Science and Engineering Department and Coordinated Science Laboratory University of Illinois Urbana IL USA Department of Electrical and Computer Engineering University of California Santa Barbara CA USA

In this paper we study the stability and L 2 -gain properties of a class of hybrid systems that exhibit linear flow dynamics, periodic time-triggered jumps and arbitrary nonlinear jump maps. This class of hybrid systems is relevant for a broad range of applications including periodic event-triggered control, sampled-data reset control, sampled-data saturated control, and certain networked control systems with scheduling protocols. For this class of continuous-time hybrid systems we provide new stability and L 2 -gain analysis methods. Inspired by ideas from lifting we show that the stability and the contractivity in L 2 -sense (meaning that the L 2 -gain is smaller than 1) of the continuous-time hybrid system is equivalent to the stability and the contractivity in L 2 -sense (meaning that the ℓ 2 -gain is smaller than 1) of an appropriate discrete-time nonlinear system. These new characterizations generalize earlier (more conservative) conditions provided in the literature. We show via a reset control example and an event-triggered control application, for which stability and contractivity in L 2 -sense is the same as stability and contractivity in ℓ 2 -sense of a discrete-time piecewise linear system, that the new conditions are significantly less conservative than the existing ones in the literature. Moreover, we show that the existing conditions can be reinterpreted as a conservative ℓ 2 -gain analysis of a discretetime piecewise linear system based on common quadratic storage/Lyapunov functions. These new insights are obtained by the adopted lifting-based perspective on this problem, which leads to computable L 2 -gain (and thus L 2 -gain) conditions, despite the fact that the linearity assumption, which is usually needed in the lifting literature, is not satisfied.

关键词： Stability analysis Control systems Numerical stability Nonlinear systems Linear systems Linearity Electronic mail

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Effect of plasma density enhancement during plasma ion implantation

Effect of plasma density enhancement during plasma ion impla...

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IEEE International Conference on Plasma Science (ICOPS)

作者： Michael P. Bradley Department of Computer and Communication System Engineering Universiti Putra Malaysia (UPM) Serdang Selangor Malaysia School of Mechanical Engineering Southwest Jiaotong University Chengdu China

ISBN: (纸本)9781467396028

Summary form only given. Plasma density enhancement is frequently observed during plasma ion implantation processes 1 . It can most clearly be measured using an optically isolated Faraday cup with secondary electron suppression. It manifests itself a significantly increased current density to the target, which persists after the transient high current pulse to the target has decayed. The enhanced plasma density presents issues for accurate dosimetry in plasma ion implantation processes. While it can be modeled using an empirically determined density enhancement factor 2 , a first-principles approach would be preferable. This paper discusses the mechanisms leading to plasma density enhancement, their modeling in the context of plasma ion implantation processes, and their implications for accurate dosimetry in plasma ion implantation applied to semiconductor processing and other applications.

关键词： Ion implantation Plasma density Optical variables measurement Physics Plasma measurements Semiconductor device measurement

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A design to improve Selective Catalytic Reduction for diesel engines

A design to improve Selective Catalytic Reduction for diesel...

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IEEE Southeastcon

作者： Ilteris Demirkiran Marc Compere Sun Ye Anuj Sharma Amay Desai Kurt Pedrosa Electrical Computer Software and System Engineering Embry-Riddle Aeronautical University Daytona Beach FL USA Mechanical Engineering Embry-Riddle Aeronautical University Daytona Beach FL USA Electrical Computer Software and System Engineering Embry-Riddle Aeronautical University Daytona Beach FL US

An approach to reduce harmful emissions in diesel engines is presented. This approach makes use of an improved Selective Catalytic Reduction (SCR) system which employs a Diesel Oxidation Catalyst (DOC). In addition, a communication link between the engine and a data collection system is established using User Datagram Protocol (UDP). We observed that the enhanced emissions control system presented demonstrates significant reduction in emission.

关键词： Thyristors Diesel engines Temperature sensors Control systems Heat pumps

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A comparative study on Vibration- and current-based approaches for drivetrain gearbox fault diagnosis

A comparative study on Vibration- and current-based approach...

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Conference Record of the IEEE Industry Applications Society Annual Meeting (IAS)

作者： Xiaohang Jin Fangzhou Cheng Yayu Peng Wei Qiao Liyan Qu College of Mechanical Engineering Zhejiang University of Technology Hangzhou Zhejiang China Power and Energy System Laboratory Department of Electrical and Computer Engineering University of Nebraska-Lincoln Lincoln NE USA

ISBN: (纸本)9781479983988

Gearboxes are widely used in rotary machines, such as wind turbines, automobiles, and helicopters. Failures of gearboxes contribute to a significant portion of the total failures and downtime in these machines. Gearbox fault diagnosis is an effective means to prevent catastrophic failures, improve the reliability, and reduce the downtime and maintenance cost of these machines. Vibration-based approaches have been employed in most commercially available condition monitoring systems (CMSs); while current-based approaches have received increasing attentions in the industry and academia. This paper presents a comparative study on the vibration- and current-based approaches for gearbox fault diagnosis. Theoretical analysis and experimental tests are carried out to show that: in vibration signals, ghost frequencies appear when the gearbox is healthy and disappear when a gear fault occurs; vibration signals of a faulty gearbox are modulated by shaft rotating frequencies at gear meshing frequencies (GMFs); in current signals, the fundamental frequency component is dominant when the gearbox is healthy; and current signals are modulated by gearbox characteristic frequencies at the fundamental frequency when gear faults appear.

关键词： Frequency measurement Current measurement Reliability Vibration measurement Monitoring computers Software

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RETRACTED ‘Application of adaptive neuro-fuzzy technique to determine the most relevant variables for daily soil temperature prediction at different depths’

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CATENA 2017年 149卷 446-446页

作者： Kasra Mohammadi Shahaboddin Shamshirband Amirrudin Kamsin Raja Jamilah Raja Yusof Department of Mechanical and Industrial Engineering University of Massachusetts Amherst MA 01003 USA Department of Computer System and Technology Faculty of Computer Science and Information Technology University of Malaya Kuala Lumpur Malaysia Department of Software Engineering Faculty of Computer Science and Information Technology University Malaya 50603 Kuala Lumpur Malaysia

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A Design Procedure of Classical Ceramic Pieces Using Geometric Parameters and the Successive Zooming Genetic Algorithm

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Journal of the Chinese Society of mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Ch'eng Hsuebo Pao 2016年第2期37卷 147-154页

作者： Kwon, Young-Doo Lee, Dae-Suep Kwon, Hyun-Wook School of Mechanical Engineering & IEDT Kyungpook National University Daegu 702-701 Korea Republic of School of Computer Aided Mechanical Engineering Yeungjin College Daegu 702-721 Korea Republic of System Solution Research Depart Research Institute of Industrial Science & Technology Pohang 790-330 Korea Republic of

The shapes of the ancient ceramics are represented by geometric parameters (user and design). The role of user parameters could be interpreted to meet basic characteristics such as: stability, beauty and utility. After understanding the basic design philosophy, an objective function could be established as the total weight of the ceramic piece subjected to the volume and strength requirements, and it was optimized by adopting the successive zooming genetic algorithm to figure out the design parameters. The redesigned pieces are very similar to the master pieces that consider basic factors;however, they satisfy the constraints exactly. © 2016, Chinese mechanical engineering Society. All right reserved.

关键词： Genetic algorithms

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A nonsmooth Kalman filter for state estimation of positioning stage based on sandwich model with backlash-like hysteresis

A nonsmooth Kalman filter for state estimation of positionin...

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American Control Conference (ACC)

作者： Yonghong Tan Yanyan Li Ruili Dong Xiang Chen Hong He College of Information Mechanical and Electrical Engineering Shanghai Normal University Shanghai China Institute of Robotics and Automatic Information System Nankai University Tianjin China Department of Electrical and Computer Engineering University of Windsor Windsor ON Canada

In this paper, a nonsmooth Kalman filtering (NKF) strategy is proposed for state estimation of macro-motion positioning stages with ball-screw-nut transmission mechanism. In this method, the characteristic of the positioning stage is described by so-called sandwich state-space model with backlash-like hysteresis. By considering the influence of random noise on positioning stage, based on the dynamic model with backlash-like hysteresis, a nonsmooth Kalman filter is proposed for state estimation of positioning stage in noisy environment. Moreover, a method of observability test for sandwich systems with backlash-like hysteresis is developed for observability check before the nonsmooth Kalman filter is implemented. Finally, the proposed NKF method is applied to a positioning stage for state estimation.

关键词： Hysteresis Kalman filters State estimation Noise measurement Observability Stochastic processes

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Strategies for driving and egress for the vehicle of a humanoid robot in the drc finals 2015

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Journal of Institute of Control, Robotics and systems 2016年第11期22卷 912-918页

作者： Dong, Hyun Ahn Ju, Seong Shin Jun, Youngbum Sohn, Kiwon Jang, Giho Oh, Paul Cho, Baek-Kyu Department of Mechanics and Design Kookmin University Korea Republic of School of Mechanical System Engineering Kookmin University Korea Republic of Howard R. Hughes College of Engineering University of Nevada Las Vegas United States Samuel I. Ward Department of Electrical and Computer Engineering University of Hartford West HartfordCT United States

This paper presents various strategies for humanoid vehicle driving and egress tasks. For driving, a tele-operating system that controls a robot based on a human operator's commands is built. In addition, an autonomous assistant module is developed for the operator. Normal position control can result in severe damage to robots when they egress from vehicles. To prevent this problem, another approach that mixes various joint control techniques is adopted in this study. Additionally, a footplate is newly designed and attached to the vehicle floor for the ground landing phase of the egress task. The attached plate enables the robot to step down onto the ground in a safe manner. For stable locomotion, a balance controller is designed for the humanoid. For the design of the controller, the robot is modeled using an inverted pendulum that consists of a spring and a damper. Then, a state feedback controller (with pole placement and a state observer) is built based on the simplified model. Many approaches that are presented in this paper were successfully applied to a full-sized humanoid, DRC-HUBO+, in the DARPA Robotics Challenge Finals, which were held in the United States in 2015.

关键词： Anthropomorphic robots

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Analysis of electrical tree inhibitory effect by antioxidants using quantum chemical calculation

Analysis of electrical tree inhibitory effect by antioxidant...

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Conference on Electrical Insulation and Dielectric Phenomena, (CEIDP)

作者： H. Uehara Y. Sekii T. Takada Y. Cao Dept. of Science and Engineering Kanto Gakuin University Yokohama Kanagawa Japan Dept. of Mechanical System Engineering Tokyo City University Setagaya Tokyo Japan SEKII PE LABORATORY Narashino Chiba Japan Dept. of Electrical and Computer Engineering University of Connecticut Storrs CT USA

ISBN: (纸本)9781509046553

This paper describes the effect of electrical tree inception voltage on antioxidants mixed in XLPE by using the density functional theory (DFT) approach. It already has been demonstrated experimentally that among the four phenolic antioxidants, 3-methyl-6-tert-butylphenol has the highest tree inception voltage. First, it is shown DFT calculation results which are the energy levels, electric dipole moment and 3D electrostatic potential distributions of antioxidants. We could be confirmed that the electrical tree inception voltage increases with increasing the electric dipole moment of antioxidants, and the inhibitory effect becomes larger when the phenolic antioxidant contains sulfur. The DFT approach is very useful to consider the mechanism of the relationship between tree inception voltage and antioxidants mixed in XLPE.

关键词： Electric potential Three-dimensional displays Electrostatics Charge carrier processes Discrete Fourier transforms Chemicals Energy states

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Constructions of Lyapunov Functions for Large-scale Networked Control systems with Packet-based Communication

Constructions of Lyapunov Functions for Large-scale Networke...

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European Control Conference

作者： W.P.M.H. Heemels D.P. Borgers V.S. Dolk R. Geiselhart S.H.J. Heijmans the Control System Technology Group Department of Mechanical Engineering Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands the Faculty of Computer Science and Mathematics of the University of Passau Innstrasse 33 94032 Passau Germany

ISBN: (纸本)9781509025923

In this tutorial presentation we focus on the construction of Lyapunov or storage functions for large-scale networked control systems (NCSs) in which sensors, controllers and actuators are connected via multiple (local) communication networks which operate asynchronously and independently of each other. Within each packet-based communication network only one node can communicate at a given transmission time (requiring communication protocols) and the transmission intervals and delays may vary over time. These artefacts cause network-induced communication errors in the overal closed-loop system and can be detrimental for stability and performance. For these NCSs we provide explicit constructions of Lyapunov functions by modelling the large-scale NCS as an interconnection of a finite or even an infinite number of hybrid subsystems, and combining 'local' Lyapunov functions for the controlled dynamics (including network-induced errors) and the protocols in a systematic manner. These constructions lead to the numerical computation of maximum allowable transmission intervals (MATIs) and maximum allowable delays (MADs) for each of the individual networks. The availability of the Lyapunov or storage functions guarantee properties such as global asymptotic or exponential stability, input-to-state stability (ISS) and, L_p-stability for the large-scale NCS. Interestingly, the control performance expressed in terms of ISS and L_p-gains can be traded with the network parameters (MATIs and MADs). Hence, tradeoffs can be made between the quality-of-control of the overal hybrid system and the required quality-of-service of the underlying communication infrastructure. Also event-triggered communication schemes will be shortly discussed. The results are illustrated with an example of vehicle platooning.

关键词： NCSs Constructions Lyapunov Functions

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