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On the nonlinear output regulation problem - Part 1 - MIMO nonlinear systems normal forms and a discussion on the necessary conditions for solving the control problem

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UPB Scientific Bulletin, Series A: Applied Mathematics and Physics 2012年第4期74卷 3-16页

作者： Udrea, Andreea Ticlea, Alexandru Flutur, Cristian Tanasa, Valentin Department of Automatic Control and Systems Engineering University POLITEHNICA of Bucharest Romania Department of Automatic Control and Computers University POLITEHNICA of Bucharest Romania

In this paper the general problem of output regulation when dealing with nonlinear MIMO systems is presented. In this context, normal forms for nonlinear systems are of great importance. Two normal forms for MIMO nonlinear systems are presented. The first one reveals the relative degrees vector and can be applied for square invertible systems (classic normal form), while the second can be used for non square systems and gives details on the system invertibility properties (recent normal form). The necessary conditions for solving the output regulation problem for the classical normal form and, respectively, the recent normal form are presented. From this discussion it results that the problem can be solved under weaker assumptions if considering the later form (obtained by using the infinite zero structure algorithm). This approach also permits discussing the regulation problem for non square MIMO systems.

关键词： MIMO systems

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Microcontroller based fuzzy-PI approach employing control surface discretization

Microcontroller based fuzzy-PI approach employing control su...

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2012 20th Mediterranean Conference on control and Automation, MED 2012

作者： Velagic, Jasmin Kuric, Muhamed Dragolj, Edin Ajanovic, Zlatan Osmic, Nedim Department of Automatic Control and Electronics Faculty of Electrical Engineering University of Sarajevo Zmaja od Bosne 71000 Bosnia and Herzegovina

ISBN: (纸本)9781467325318

This paper proposes an approach of digital controller design on microcontrollers based on control surface disretization. As experimental setup a simple system composed of a DC motor, the PWM drive and a encoder was built. Identification of this simple system was done using the first order linear model and the Hammerstein-Wiener model. The quality of these models was compared based on the fitness function and their ability to cope with system nonlinearities. A discrete PI speed controller was designed based on the Hammerstein-Wiener model and tuned by the Gauss-Newton optimization algorithm. The Fuzzy logic controller was designed on the basis of the PI controller behaviour with genetic algorithm parameter tuning. The control surface of the Fuzzy logic controller was discretized for microcontroller implementation. Both controllers were implemented on the Arduino Mega platform and their control performances were tested and compared. © 2012 IEEE.

关键词： Genetic algorithms

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Spatio-temporal error concealment algorithms for encoded video streams for real-time applications

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International Journal of computers and Applications 2012年第2期34卷 105-118页

作者： Sarhan, Amany Mahmoud, Rasha O. Faheem, Mohamed T. Computers and Automatic Control Engineering Department Faculty of Engineering Tanta University Egypt Computer Science Department Nile Institute of Commerce and Computer Technology Mansoura Egypt Computers and Automatic Control Engineering Department Faculty of Engineering Taief University Saudi Arabia

Multimedia is one of the most important aspects of the information era. With the advent of the multimedia age and the spread of Internet, video storage and streaming has been gaining a lot of popularity. When transmitting compressed video over a data network channel errors affect the decoding process. Video transmission puts constraints on data rate, computational complexity and delay. Unreliable channels add more challenges to this task as compressed video is extremely vulnerable to transmission errors. Problems arising from imperfect transmission of block coded video frame sequence result in lost blocks. This paper presents and implements a set of decoder side spatio-temporal algorithms that aim to enhance the speed and quality of the error concealment process. The results obtained by these algorithms are much faster and achieve better performance compared to the existing algorithms, which make them more suitable for real-time applications.

关键词： Image communication systems

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Obstacle Avoidance for Trajectory Tracking control of Wheeled Mobile Robots

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IFAC Proceedings Volumes 2012年第6期45卷 906-911页

作者： Razvan Solea Daniela Cristina Cernega “Dunarea de Jos” University of Galati Faculty of Automatic Control Computers Electrical and Electronics Engineering Romania

In this paper the authors investigated a new trajectory-tracking method for the wheeled mobile robots in the presence of static and dynamic obstacles. The model of steering and obstacle avoidance consists in a system of differential equations. The sensory perception is based on a laser range finder (LRF) system. The trajectory tracking control problem is solved using the sliding mode control. Simulation results are presented to verify the effectiveness of the proposed local navigational system in unknown environments with static and moving objects, corresponding to a flexible manufacturing system.

关键词： Mobile robots Nonlinear control system Sliding-mode control Obstacle avoidance

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Efficient state reference generation for torque control in externally excited synchronous machines

Efficient state reference generation for torque control in e...

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2012 16th International Conference on system Theory, control and Computing, ICSTCC 2012

作者： Carpiuc, Sabin-Constantin Lazar, Mircea Faculty of Automatic Control and Computer Engineering Technical University Gheorghe Asachi of Iasi Romania Department of Electrical Engineering Eindhoven University of Technology Netherlands

ISBN: (纸本)9786068348483

A difficult challenge in hybrid electric vehicles (HEVs) and full electric vehicles (EVs) is the torque control of externally excited synchronous machines (EESMs). Effective torque control requires an efficient solution to the state reference generation problem, which is a nonlinear non-convex optimization problem. The goal of this paper is to develop a state reference generation algorithm based on the griding of the state and output spaces. Firstly, an approximation defined over a cubic partition of the torque function with a piecewise affine (PWA) function is made. As a result, the state reference generation problem is reduced in each cube to solving a convex optimization problem. Moreover, this approach provides guarantees about the error bound introduced by the state reference generation procedure for the full operational state-space. To illustrate the effectiveness and robustness of the proposed algorithm several simulation results are presented. The obtained results show significant improvement compared with existing state-of-the-art reference generation methods. © 2012 Dunarea de Jos University.

关键词： Torque control

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Comparative Study of Three Phase 3-Leg Active Power Filters Connected to 4-Wire Electrical systems

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Journal of Energy and Power engineering 2012年第9期6卷 1527-1535页

作者： Ciprian Balanuta Gelu Gurguiatu Toader Munteanu Grigore Fetecau Olimpia Grozavu Department of A utomatic Control and Electrical Engineering Faculty of Automatic Control Computers Electrical and ElectronicsEngineering "Dun(trea de los" University Gala l~" 800008 Romania

This paper presented the simulation results of the three phase electrical systems supplied by four wires with power quality problems, to which the parallel 3-leg APF （active power filters） are connected. The purpose of this study is to analyze the results obtained in these conditions in order to observe the limits of the 3-leg active power filters and to form a foundation for the future studies of the 4-leg active power filters. For a complete analysis, the APF will be controlled by four control methods： synchronous reference system control, indirect control, instantaneous p-q theory control, and positive sequence control. The analysis will watch the power quality indicators： THD （total harmonic distortion factor）, PF （power factor）, Iunb （unbalance factor）.

关键词： Power quality active power filter control method.

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Optimization algorithm for mobile robot paths in the presence of multiple obstacles

Optimization algorithm for mobile robot paths in the presenc...

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2012 IEEE International Conference on Consumer Electronics, ICCE 2012

作者： Al Zeer, Ghaida Nabout, Adnan Abou Tibken, Bernd Department of Automatic Control Faculty of Electrical Information and Media Engineering University of Wuppertal Rainer-Gruenter-Str. 21 42119 Wuppertal Germany

ISBN: (纸本)9781457702310

This paper presents path planning optimization for mobile robots using approximate routes. The desired path connects a given starting position to a target position under avoidance of static obstacles. The described approach of path planning using approximate routes is based on the determination of suitable reference points as auxiliary positions. The auxiliary positions, together with the starting and target position, form a polygonal path as a collision-free-route. Obstacles are considered usually in an order depending on their distances from the starting position. According to this fact we obtain collision-free paths, which vary in their properties (overall length, number of the steering events and intensity of the steering events) depending on the location and the form of the obstacles. Therefore in the presence of multiple obstacles, we can generate all possible paths by using all permutations for the order of the obstacles. Then the best of these paths can be chosen with respect to some optimality criterion that takes into account the above-mentioned properties. The results of this method will be discussed based on Matlab simulations and an implementation as part of the development of a system for fully automated stock-keeping. © 2012 IEEE.

关键词： Motion planning

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Improved vertex control for a ball and plate system

Improved vertex control for a ball and plate system

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7th IFAC Symposium on Robust control Design, ROCOND'12

作者： Nguyen, H.-N. Olaru, S. Gutman, P.-O. Hovd, M. Automatic Control Department Sweden Faculty of Civil and Environmental Engineering Technion - Israel Institute of Technology Israel Department of Engineering Cybernetics Norwegian University of Science and Technology Norway

ISBN: (纸本)9783902823038

This paper deals with a ball and plate experiment and the objective is twofold. In the first part, a solution to the identification problem for this multi-input multi-output system is provided. In the second part an improved vertex control technique, recently proposed in literature (Nguyen et al. [2011b], Nguyen et al. [2011a]), is applied for stabilizing the ball and plate system. Based on an interpolation technique, feasibility and an asymptotically stable closed loop behavior are guaranteed. © 2012 IFAC.

关键词： Interpolation

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Transformer's automatic local voltage control in electrical power systems

UPB Scientific Bulletin, Series C: Electrical Engineering

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UPB Scientific Bulletin, Series C: Electrical engineering 2012年第4期74卷 67-78页

作者： Constantin, Iulia Cristina Constantin, Costel Iliescu, Sergiu Stelian Automatic Control and Computers Faculty University Politehnica of Bucharest Romania Power Engineering Faculty University Politehnica of Bucharest Romania

In order to maintain in tolerable ranges the voltages of a power system the centralized and the local regulation are combined. The paper is proposing to relieve the importance of the local regulation/control, maintaining in tolerable ranges the voltages in a specified bus of a power system using the power transformers/autotransformers equipped with an automatic voltage control device. The paper also proposes a solution for implementing and setting an automatic voltage control device for a substation of the national power system, in which is not implemented for the moment this kind of regulating solution, and analyze the its behavior for different operating conditions. The study was made in a very important 400/220/110 kV substation of the transmission network of the Romanian National Power system on a 400/220 kV and 400 MVA autotransformer. Copyright © 2009 Universitatea Politehnica Bucuresti.

关键词： Power transformers

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An empirical evaluation and improvement of the item balancing algorithm in P2P systems

An empirical evaluation and improvement of the item balancin...

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2012 8th International Conference on Computing Technology and Information Management, ICCM 2012

作者： Helmy, Tarek Al-Herz, Ahmed College of Computer Science and Engineering King Fahd University of Petroleum and Minerals Mail Box. 413 Dhahran 31216 Saudi Arabia College of Engineering Department of Computers Engineering and Automatic Control Tanta University Egypt

ISBN: (纸本)9788988678671

Load balancing is one of the main issues in structured Peer-to-Pear (P2P) systems. An improvement in the load balancing algorithm can significantly enhance the resources utilization and fairness in P2P systems. Load balancing across multiple nodes has been widely studied in P2P systems. Some proposals exist for load balancing in P2P systems in which each node maintains log n virtual servers and allows the address space to be partitioned equally but the degree of each node is log2n which is not desirable. Karger & Ruhl proposed an algorithm that simultaneously offers a node degree of log n and an equal partition of the address space. We propose an improvement to Karger and Ruhl algorithm by adopting greedy randomize approach which improves the variance of number of items across all peers significantly using additional peers' load information. We simulate the Karger and Ruhl item balancing algorithm, evaluate its load balancing results then simulate the improved item balancing algorithm and evaluate its load balancing results. The results of the improved algorithm are compared with the results of the original algorithm. The results of the performance comparison show better load balance using the improved algorithm;around 40% in the variance by using only 1% of the number of peers in the system. © 2012 AICIT.

关键词： Fruits

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