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UPB Scientific Bulletin, Series C: Electrical Engineering 2012年第4期74卷 27-38页

作者： Pintea, Andreea Popescu, Dumitru Dept. of Automatic Control and Computer Science Politehnica University Bucharest Romania

This paper presents a comparative study of two well known regulation algorithms designed for a horizontal variable wind speed turbine functioning in the above rated wind speed regime. Typical control in this working regime uses pitch regulation to maintain constant the turbine's rotor speed while the generator toque is held constant. This will be also the approach chosen for this study. The goal of the paper is to demonstrate the efficiency of the two algorithms in controlling the electrical output power by means of applying them on a simplified model of a wind turbine. The obtained results will be analyzed and presented through a few simulations. Copyright © 2009 Universitatea Politehnica Bucuresti.

关键词： Wind turbines

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A WSN based monitoring system for oil and gas transportation through pipelines

A WSN based monitoring system for oil and gas transportation...

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14th IFAC Symposium on Information control Problems in Manufacturing, INCOM'12

作者： Junie, Petru Dinu, Octav Eremia, Cristian Stefanoiu, Dan Petrescu, Catalin Savulescu, Ioan Politehnica University of Bucharest Dept. of Automatic Control and Computer Science 313 Splaiul Independentei Bucharest-060042 Romania Oil and Gas University of Ploiesti Dept. of Drilling and Extraction 39 Bucuresti Blvd. Ploiesti-100680 Romania

ISBN: (纸本)9783902661982

This article introduces some results obtained in monitoring of long pipelines employed in oil and gas transportation. A mobile unit for signals acquisition, processing, identification and diagnosis (MUSAPID), based on wireless sensors networks (WSN) technology was employed. The MUSAPID architecture was adapted to match the configuration of monitoring system, inspired by the national energy dispatcher. Thus, the system includes four hierarchical levels assigned to: the central dispatcher, the zonal dispatcher, the local dispatcher and the sensor nodes. The sensors are acquiring the flow and temperature of oil from the monitored pipeline. Sensors distribution along the pipeline is of in-line type. Nevertheless, a cross-link schema between sensor nodes is proposed, in order to increase the exploitation safety and to reduce false alarms sending. Two independent monitoring approaches based on comparison between values of sensors in pairs of successive nodes allow controlling the occurrence of rifts and leaks in the pipeline network. One of the approaches is unconventional and uses inter-correlation between the data acquired from two successive sensor nodes, as well as auto-correlation of temperature data. A simple logic to avoid sending false alarms was also implemented. © 2012 IFAC.

关键词： Sensor nodes

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Correcting open-answer questionnaires through a Bayesian-network model of peer-based assessment

Correcting open-answer questionnaires through a Bayesian-net...

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2012 International Conference on Information Technology Based Higher Education and Training, ITHET 2012

作者： Sterbini, Andrea Temperini, Marco Dept. Computer Science. Sapienza University of Rome Rome Italy Dept. Computer Control and Management Engineering Sapienza University of Rome Rome Italy

ISBN: (纸本)9781467323345

We have previously shown that, with the help of peer-assessment and of a finite-domain constraint-based model of the student's decisions, the teacher could have a complete assessment of the answers to open-ended questions, by grading just a subset of the answers (as low as half of the lot) and having the rest of the grading inferred by the supporting system. In this paper we present a probabilistic version of the earlier model, using Bayesian networks instead than constraints. Our aims are both defining the approach and prepare its validation: 1) modeling the peer-assessment activity of a student that evaluates others' answers, 2) using peer-assessment to help the teacher with a faster/shorter assessment process, 3) inferring the student's level of competence and ability to judge, from peer-assessment and from (partial) teacher-assessment, 4) learning the conditional probabilistic tables (CPTs) of the model from student data, and 5) comparing the probability distribution of competences in the class at different course phases. The model is under development and test with real data. We are developing a web-based interface to deliver open-answer and peer-assessment questionnaires and to assist the teacher-assessment. © 2012 IEEE.

关键词： Bayesian networks

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Integrated Time-Optimal Trajectory Planning and control Design for Industrial Robot Manipulator

Integrated Time-Optimal Trajectory Planning and Control Desi...

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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Stepan S. Pchelkin Anton S. Shiriaev Anders Robertsson Leonid B. Freidovich Department of Engineering Cybernetics Norwegian University of Science and Technology NO-7491 Trondheim Norway. Department of Applied Physics and Electronics Ume? University SE-901 87 Ume? Sweden. Dept. of Automatic Control Lund University SE-221 00 Lund Sweden and is member of the LCCC Linnaeus Center and the ELLIIT Excellence Center at Lund University.

ISBN: (纸本)9781467363563

We consider planning and implementation of fast motions for industrial manipulators constrained to a given geometric path. With such a problem formulation, which is quite reasonable for many standard operation scenarios, it is intuitively clear that a feedback controller should be designed to achieve orbital stabilization of a time-optimal trajectory instead asymptotic. We propose an algorithm to convert an asymptotically stabilizing controller into an orbitally stabilizing one and check achievable performance in simulations and, more importantly, in experiments performed on a standard industrial robot ABB IRB 140 with the IRC5-system extended with an open control interface. It is verified that the proposed re-design allows significantly reduced deviations of the actual trajectories from the desired one at high speeds not only for a chosen base feedback design but also outperforming the state-of-the-art commercial implementation offered by ABB Robotics.

关键词： Motion and trajectory planning with constraints Orbital stabilization Time optimal control Industrial manipulators

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Pros and cons of horizontal axis wind turbines linear identification

Frontiers in Artificial Intelligence and Applications

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Frontiers in Artificial Intelligence and Applications 2012年 243卷 684-695页

作者： Stefanoiu, Dan Tudor, Florin Sebastian Politehnica University of Bucharest Dept. of Automatic Control and Computer Science 313 Splaiul Independentei Bucharest-060042 Romania

ISBN: (纸本)9781614991045

This article outlines some of the advantages and disadvantages of wind turbines linear identification, in case of minimal number of measuring channels. The identified turbine has horizontal axis and belongs to middle size class. Multi-variable models of linear type (Box-Jenkins (BJ) / ARMAX, state space representation) are estimated and compared in terms of fitness in time, as well as in frequency. All models are validated by data acquired from a running turbine, in conditions of variable but rather weak wind activity. Linear models do not match very well HAWTs, though some BJ models are behaving fairly. © 2012 The authors and IOS Press. All rights reserved.

关键词： Horizontal axis wind turbine

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A distributed newton iteration based localization scheme in underground tunnels

A distributed newton iteration based localization scheme in ...

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2012 UKACC International Conference on control, control 2012

作者： Qin, Yuanqing Zhou, Chunjie Yang, Shuang-Hua Wang, Fang Dept. of Control Science and Engineering Huazhong University of Science and Technology Wuhan China Computer Science Department Loughboroug University Loughboroug United Kingdom

ISBN: (纸本)9781467315609

One of the main concerns in underground working tunnels is ensuring the safety of the workers and their equipment. Being aware of the real-time position of personnel in such harsh environment is challenging and requires a sophisticated localization system. With traditional Received Signal Strength (RSS) failing to accurately estimate the distance between nodes due to multipath effect in such long and narrow space, Radio Frequency Time-of-Flight (RF-TOF) is proved to be an alternative method for more accurate distance estimation. To reduce the communication cost, a distributed localization scheme is proposed, where a simple Newton Iteration location estimation algorithm is embedded in the blind node. Linear least square estimation is used as the initial value to accelerate the convergence of the iteration. Experimental results show the effectiveness of the proposed scheme. © 2012 IEEE.

关键词： Iterative methods

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Satellite orbit determination based on gradient method

Satellite orbit determination based on gradient method

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2012 24th Chinese control and Decision Conference, CCDC 2012

作者： Ashtari Larki, M.H. Maboodi, M. Bolandi, H. Faculty of Electrical Engineering Control Dept. Iran University of Science and Technology Tehran Iran Faculty of Electrical and Computer Engineering Control Dept. K.N. Toosi University of Technology Tehran Iran

ISBN: (纸本)9781457720727

In this paper, gradient method is applied to the problem of satellite orbit determination. We used the ground station data (range, azimuth and elevation), for calculating the satellite position vector in the ECI frame. Satellite orbit is in the elliptic shape and satellite turns in orbital plane. Hence, orbit frame (PQW) is defined. Based on representation of input data in the PQW frame, we can define an ellipse. With the characteristics of an ellipse, beside definition of cost function and optimization technique, the satellite orbit is determined. This method, which can be easily implemented in hardware with moderate computational complexity, yield an efficient satellite positioning without assuming a prior knowledge of measurement noise. The performance, accuracy and error of algorithm are checked, by a test case. © 2012 IEEE.

关键词： Optimization

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control of uncertain hybrid nonlinear systems using particle filters

Control of uncertain hybrid nonlinear systems using particle...

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4th IFAC Conference on Analysis and Design of Hybrid Systems, ADHS'12

作者： Asselborn, Leonhard Jilg, Martin Stursberg, Olaf Institute of Control and System Theory Dept. of Electrical Eng. and Computer Science University of Kassel 34121 Kassel Germany

ISBN: (纸本)9783902823007

This paper proposes an optimization-based algorithm for the control of uncertain hybrid nonlinear systems. The considered system class combines the nondeterministic evolution of a discrete-time Markov process with the deterministic switching of continuous dynamics which itself contains uncertain elements. A weighted particle filter approach is used to approximate the uncertain evolution of the system by a set of deterministic runs. The desired control performance for a finite time horizon is encoded by a suitable cost function and a chance-constraint, which restricts the maximum probability for entering unsafe state sets. The optimization considers input and state constraints in addition. It is demonstrated that the resulting optimization problem can be solved by techniques of conventional mixed-integer nonlinear programming (MINLP). As an illustrative example, a path planning scenario of a ground vehicle with switching nonlinear dynamics is presented. © 2012 IFAC.

关键词： Bandpass filters

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Emotion, future smart technology, and convergence

Emotion, future smart technology, and convergence

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3rd International Conference on Intelligent Systems Modelling and Simulation, ISMS 2012

作者： Kim, Dong Hwa Saeed, Kahlid Dept. of Instrumentation and Control Eng. Hanbat National University 16-1 Duckmyong dong Yuseong gu Daejeon 305-719 Korea Republic of Dept. of Physics and Applied Computer Science AGH University in Krakow Poland

ISBN: (纸本)9780769546681

This paper proposes the importance of emotion technology for future technology. Emotion technology is absolutely necessary for real human being in future technology such as robot, culture, and design etc. However, it is very difficult to approach and expression effectively emotion function in engineering. Visual system (static and moving status), sound system, and tactile sense can express by physical sensor. However, there are some difficulties about how we can express feeling like human being's hart in engineering. Therefore, those who work in science have to cooperate with researcher in quite difference area such as, literature, designer, psychologist, philosopher, musician, material science, and etc. © 2012 IEEE.

关键词： Philosophical aspects

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Fast exemplar-based image inpainting approach

Fast exemplar-based image inpainting approach

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2012 International Conference on Machine Learning and Cybernetics, ICMLC 2012

作者： Wang, Hui-Qin Chen, Qing Hsieh, Cheng-Hsiung Yu, Peng Information and Control Engineering College Xi'an University of Architecture and Technology Xi'an 710055 China Dept. of Computer Science and Information Engineering Chaoyang University of Technology Taichung 41349 Taiwan

ISBN: (纸本)9781467314855

This paper presents a way to improve the computation efficiency of exemplar-based inpainting approach in [4]. Note that the inpainting approach in [4] has computation redundancy in searching optimal patches in source region and updating fill front. A scheme to reduce source region and a modified scheme to update fill front are proposed. With the two schemes, better computation efficiency is expected. Several examples are given to justify the proposed fast inpainting approach and used to compare with the approach in [4]. The results indicate that the proposed approach has better computation efficiency than the approach in [4], as expected. Interesting enough, better visual quality of inpainted images is achieved by the proposed approach as well. © 2012 IEEE.

关键词： Computational efficiency

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