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Real-Time Takagi-Sugeno Fuzzy Control of a Robot Manipulator

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS 2009年第11期24卷 1174-1201页

作者： Garcia-Hernandez, Ramon Ruz-Hernandez, Jose A. Sanchez, Edgar N. Santibanez, Victor Llama, Miguel A. Univ Autonoma Carmen Cd Del Carmen 24180 Campeche Mexico CINVESTAV Unidad Guadalajara Guadalajara 62490 Jalisco Mexico Inst Tecnol Laguna Torreon 27001 Coahuila Mexico

This paper presents the development of a control algorithm, which combines the linear regulator theory and Takagi-Sugeno (T-S) fuzzy modeling. Each local controller consists in a feedback control term plus a trajectory tracking term. The global controller is determined by means of T-S methodology. Then, the proposed algorithm is applied in real time on a robot manipulator. (C) 2009 Wiley Periodicals, Inc.

关键词： TRACKING Robot Manipulator tracking Fuzzy control local controller feedback control computer algorithms linear quadratic regulators

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Structural damage detection using enhanced damage locating vector method with limited wireless sensors

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JOURNAL OF SOUND AND VIBRATION 2009年第4-5期328卷 411-427页

作者： Quek, S. T. Tran, V. A. Hou, X. Y. Duan, W. H. Natl Univ Singapore Dept Civil Engn Singapore 117576 Singapore

For detection of damage in structures, the damage locating vector (DLV) method is adapted to account for the different types and variations of internal forces and capacities along the length of each element by using the normalized cumulative energy instead of the normalized cumulative stress. To filter out the actual damaged elements from the identified set of potential damaged elements, an intersection scheme is proposed. A 2-D warehouse structure comprising beam and column elements with constant and varied cross-sectional areas, and truss elements is used to verify the enhancements to the DLV method. With wireless sensors being integrated into damage detection systems, practical issues need to be addressed in conjunction with the detection algorithm employed. For cases where raw signals are transmitted, the intermittent loss of data packets during transmission from the sensor nodes to the base station needs to be addressed. An algorithm to patch the lost data is proposed and when integrated with the DLV damage detection methodology, is experimentally shown to be feasible using a 3-D modular truss structure. (C) 2009 Elsevier Ltd. All rights reserved.

关键词： STRUCTURAL frames STRUCTURAL failures computer algorithms CROSS-sectional method TRUSSES DETECTORS DATA packets & packeting

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CURVE FITTING BASED PARTICLE SWARM OPTIMIZATION FOR UWB PATCH ANTENNA

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JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS 2009年第17-18期23卷 2421-2432页

作者： Islam, M. T. Moniruzzaman, M. Misran, N. Shakib, M. N. Univ Kebangsaan Malaysia Inst Space Sci ANGKASA Bangi 43600 Selangor De Malaysia Univ Kebangsaan Malaysia Dept Elect Elect & Syst Engn Bangi 43600 Selangor De Malaysia

An optimization technique for microstrip patch antenna using Curve Fitting based Particle Swarm Optimization (CFPSO) is presented in this paper. An E-H shaped patch antenna designed using conventional optimization technique for Ultra Wide Band (UWB) communication is utilized to demonstrate the optimization technique. The conventional optimized antenna is designed by searching an acceptable solution from amongst the invariably huge collective range of geometry variables. The data for curve fitting is obtained from EM simulator by varying different geometrical parameters of the antenna. Using the data, the equations representing the relationship among different parameters of a microstrip antenna are generated. Curve fitting software was used to generate the curve. The CFPSO program was developed and executed in MATLAB. Conventionally optimized antenna is compared with CFPSO optimized antenna in this paper. The result yields that CFPSO showed remarkable improvement over bandwidth. For the E-H shaped antenna, the bandwidth is increased by 27% compared to conventionally optimized antenna.

关键词： MICROSTRIP antennas MICROWAVE antennas STRIP transmission lines PARTICLE swarm optimization SWARM intelligence computer algorithms

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Incremental rate control for H.264/AVC video compression

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IET IMAGE PROCESSING 2009年第5期3卷 286-298页

作者： Sun, Y. Zhou, Y. Feng, Z. He, Z. Sun, S. Univ Cent Arkansas Dept Comp Sci Conway AR 72034 USA Univ Elect Sci & Technol China Coll Comp Sci & Engn Chengdu 610054 Peoples R China Acxiom Corp Conway AR 72034 USA Univ Missouri Dept Elect & Comp Engn Columbia MO 65211 USA

In this study, the authors propose a new rate-complexity-quantisation model and an incremental rate control algorithm for H.264/AVC video coding. One unique property of this algorithm is that, the picture complexity estimation and rate-quantisation modelling are jointly designed with an incremental rate control for P-frames. In addition, the proposed algorithm also introduces a number of efficient rate control techniques, including accurate rate control for intra-frames, enhanced proportional-integral-derivative (PID) buffer controller, and adaptive quantisation parameter determination for B-frames. The proposed algorithm has low computational complexity while providing robust rate control. Our extensive experimental results demonstrate that the proposed algorithm outperforms the current rate control algorithm adopted in the H.264/AVC reference software JM13.2 by achieving more accurate rate control, reducing frame skipping, depressing quality fluctuation and improving the overall coding quality by up to 2.83 dB.

关键词： rate control algorithms complexity classes computer algorithms

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How Effective is Google's Translation Service in Search?

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COMMUNICATIONS OF THE ACM 2009年第10期52卷 139-143页

作者： Savoy, Jacques Dolamic, Ljiljana Univ Neuchatel Dept Comp Sci CH-2000 Neuchatel Switzerland

The article presents the results of a study which investigated the effectiveness of Google's translation service for searching the internet using multiple languages. It was found that asking Google to automatically translate search terms reduces search effectiveness. These performance reductions were generally due to the characteristic problems associated with mechanical translation, and varied between language pairs. Using one intermediary language, into which all search terms were translated, and from which all subsequent translations were made, was found to improve the results.

关键词： Internet searching Web search engines Information retrieval Information science Information services World Wide Web computer algorithms Machine translating Translations Translating & interpreting Content-based image retrieval

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Topological analysis of 3D building models using a spatial query language

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ADVANCED ENGINEERING INFORMATICS 2009年第4期23卷 370-385页

作者： Borrmann, Andre Rank, Ernst Tech Univ Munich D-80290 Munich Germany

The paper presents parts of the development of a spatial query language for building information models. Such a query language enables the spatial analysis of building information models and the extraction of partial models that fulfill certain spatial constraints. Among other features, it includes topological operators, i.e. operators that reflect the topological relationships between 3D spatial objects. The paper presents definitions of the semantics of the topological operators within, contain, touch, overlap, disjoint and equal in 3D space by using the 9-intersection model. It further describes a possible implementation of the topological operators by means of an octree-based algorithm. The recursive algorithm presented in this article relies on a breadth-first traversal of the operands' octree representations and the application of rules that are based on the color of the octants under examination. Because it successively increases the discrete resolution of the spatial objects employed, the algorithm enables the user on the one hand to handle topological relationships in a fuzzy manner and on the other hand to trade-off between computational effort and the required accuracy. The article also presents detailed investigations on the run-time performance of the developed algorithm. (C) 2009 Elsevier Ltd. All rights reserved.

关键词： BUILDING information modeling QUERY languages (computer science) SPATIAL analysis (Statistics) FUZZY algorithms computer algorithms SYSTEM analysis

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A robust Hough transform algorithm for determining the radiation centers of circular and rectangular fields with subpixel accuracy

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PHYSICS IN MEDICINE AND BIOLOGY 2009年第3期54卷 555-567页

作者： Du, Weiliang Yang, James Univ Texas MD Anderson Canc Ctr Dept Radiat Phys Houston TX 77030 USA

Uncertainty in localizing the radiation field center is among the major components that contribute to the overall positional error and thus must be minimized. In this study, we developed a Hough transform (HT)-based computer algorithm to localize the radiation center of a circular or rectangular field with subpixel accuracy. We found that the HT method detected the centers of the test circular fields with an absolute error of 0.037 +/- 0.019 pixels. On a typical electronic portal imager with 0.5 mm image resolution, this mean detection error was translated to 0.02 mm, which was much finer than the image resolution. It is worth noting that the subpixel accuracy described here does not include experimental uncertainties such as linac mechanical instability or room laser inaccuracy. The HT method was more accurate and more robust to image noise and artifacts than the traditional center-of-mass method. Application of the HT method in Winston-Lutz tests was demonstrated to measure the ball-radiation center alignment with subpixel accuracy. Finally, the method was applied to quantitative evaluation of the radiation center wobble during collimator rotation.

关键词： computer algorithms algorithms MATHEMATICAL models MATHEMATICAL analysis

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MPC Constraint Analysis-Bayesian Approach via a Continuous-Valued Profit Function

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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 2009年第8期48卷 3944-3954页

作者： Akande, Seyi Huang, Biao Lee, Kwan Ho Univ Alberta Dept Chem & Mat Engn Edmonton AB T6G 2G6 Canada

Model predictive control (MPC) is one of the most studied modem control technologies. Among the various subjects investigated, controller performance assessment of MPC has received considerable attention in recent time. Various approaches and algorithms have been proposed for the assessment of MPCs. In this work, we propose a novel approach to MPC constraint analysis by considering the economic objective function as a continuous-valued function within a Bayesian probabilistic framework. The analysis involves inference of the effect of a decision to adjust the limits of the constrained variables with regards to the achievable profits (decision evaluation) as well as inference of constraint limits that should be adjusted so as to achieve a specified profit value (decision making). The benefits of this approach include a more generalized definition of quality variables, the development of a more rigorous formulation of the problem to address linear and quadratic objective functions and thereby obtaining closed form solutions, and maximum-likelihood location determination of the quality variables in the decision making process. The approach is illustrated with the use of simulations and a pilot-scale experiment.

关键词： PREDICTIVE control PREDICTION models BAYESIAN analysis DECISION theory CONTROL theory (Mathematics) computer algorithms MAXIMUM likelihood statistics PROBLEM solving CONTINUOUS functions

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Smoothed Analysis: An Attempt to Explain the Behavior of algorithms in Practice

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COMMUNICATIONS OF THE ACM 2009年第10期52卷 76-84页

作者： Spielman, Daniel A. Teng, Shang-Hua Yale Univ New Haven CT 06520 USA Boston Univ Dept Comp Sci Boston MA 02215 USA Akamai Technol Inc Cambridge MA USA

The article presents a method for determining whether an algorithm will work well in practice, without depending on the worst-case scenario method. Although an algorithm which performs well under worst-case conditions can always be relied on, it is also the case that many heuristic algorithms which are frequently useful under normal conditions fail under worst-case scenarios. The method of smoothed analysis is presented as a means of using real data, perturbed by a selected degree of random noise, in order to test algorithmic performance under realistic conditions.

关键词： algorithms HEURISTIC MATHEMATICAL statistics computer algorithms computer programming LINEAR programming MATHEMATICAL programming SMOOTHING (Numerical analysis) PERTURBATION (Mathematics) RANDOM noise theory COMPUTATIONAL complexity RANDOM graphs

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New Control Structure for Divided-Wall Columns

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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 2009年第13期48卷 6034-6049页

作者： Ling, Hao Luyben, William L. Lehigh Univ Dept Chem Engn Bethlehem PA 18015 USA E China Univ Sci & Technol Dept Petr Proc Shanghai 200237 Peoples R China

Industrial applications of the divided-wall column for the separation of tertiary mixtures have increased in recent years with about 40 columns reported to be in service. The divided-wall column is a practical way to implement the topology of the Petlyuk column that features two columns (a prefractionator into which the feed is introduced and a main column from which a sidestream product is withdrawn) with interconnected vapor and liquid streams arising from a single reboiler and a single condenser. Many papers discuss the steady-state design issues and propose heuristic and rigorous design optimization methods. The dynamic control of the divided-wall column has been explored in a relatively small number of papers. Control is more difficult than with a conventional two-column separation sequence because there is more interaction among controlled and manipulated variables since the four sections of the column are coupled. The vapor split is fixed at the design stage and cannot be changed during operation, but the liquid split can be manipulated to achieve some control objective. A number of control structures and algorithms have been proposed, but the reported results present a somewhat confusing pi re Different authors draw conclusions. Most papers control the purities of the three product streams using reflux flow rate, sidestream flow rate, and vapor boilup. This paper proposes a new control structure that controls these purities and also minimizes energy consumption. This is achieved implicitly by controlling a composition of the heaviest component in the prefractionator. Disturbances in feed flow rate and feed composition are used to demonstrate the effectiveness of the proposed control structure. A comparison of the dynamic controllability of the divided-wall column with a conventional configuration is also provided.

关键词： CHEMICAL engineering TECHNICAL chemistry SEPARATION (Technology) MIXTURES CHEMICAL reactors -- Design & construction CHEMICAL research CONDENSERS (Vapors & gases) computer algorithms

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