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IEEE Symposium on computers and Communications (ISCC)

作者： A.A. Saad G. Badr Computer Science and Automatic Control Department Faculty of Engineering Alexandria University Alexandria Egypt

Object-oriented database systems aim at meeting the data modelling, performance, cooperative design and version management requirements of current advanced applications, such as CAD (computer-aided design), CAM (computer-aided manufacturing), CASE (computer-aided software engineering), CIM (computer integrated manufacturing), hypermedia and expert systems. This paper presents the ALEX Object Manager, which is a part of the ALEX object-oriented database management system that is being developed based on the ODMG-93 standard. The system decomposition and process layout are presented, some implementation problems are discussed and the current status of the system is reported.

关键词： Database systems Design automation computer aided manufacturing computer aided software engineering computer integrated manufacturing Object oriented modeling engineering management Application software CADCAM Expert systems

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A Method of Robust Fault Detection for Dynamic Systems by Using Quasi-ARMAX Modeling

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IFAC Proceedings Volumes 1997年第11期30卷 1157-1162页

作者： K. Kumamaru J. Hu K. Inoue T. Söderström Department of Control Engineering and Science Faculty of Computer Science and Systems Engineering Kyushu Institute of Technology Iizuka 820 Fukuoka Japan Department of Automatic Control and Systems Analysis Institute of Technology Uppsala University P.O.Box 27 Uppsala Sweden

This paper presents a model-based approach to fault detection of dynamic systems, which is robust to unmodeled dynamics. A “Quasi-ARMAX model᾿ is first proposed for describing nonlinear systems by incorporating a group of certain nonlinear structures into a linear ARMAX structure. The model can be used for a best linear approximation of the system, as well as for the estimation of resulting unmodeled dynamics, by a hierarchical implementation of recursive identification. Then robust fault detection is performed based on thresholding approach using Kullback discrimination information as fault detection index, in which the estimated unmodeled dynamics is incorporated.

关键词： Dynamic systems fault detection Kullback discrimination information modeling errors nonlinear systems robust performance

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Fault Detection of Nonlinear Systems by Using Hybrid Quasi-ARMAX Models

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IFAC Proceedings Volumes 1997年第18期30卷 1125-1130页

作者： K. Kumamaru J. Hu K. Inoue T. Söderström Department of Control Engineering and Science Faculty of Computer Science and Systems Engineering Kyushu Institute of Technology Iizuka 820 Fukuoka Japan. Department of Automatic Control and Systems Analysis Institute of Technology Uppsala University P.O.Box 27 Uppsala Sweden

This research is concerned with fault detection of nonlinear systems using Kullback discrimination information (KDI) as an index. A hybrid quasi-ARMAX model is proposed, which combines a linear ARMAX model and a multi-ARX-model based on interpolation. In the case where the faults occur on the ARMAX model part, a KDI-based "robust" fault detection is performed, in which multi-ARX-model part is treated as error due to nonlinear undermodeling. In other cases, the model is transformed into several local ARMAX models and fault detection is performed by using the KDI to discriminate each identified local model. In this paper, we mainly concentrate our discussion on the latter cases.

关键词： Nonlinear systems dynamic systems fault detection Kullback discrimination information quasi-ARMAX modeling local model

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Multiobjective control for continuous time MIMO systems via deadbeat regulation

Multiobjective control for continuous time MIMO systems via ...

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IEEE Conference on Decision and control

作者： K. Tsumura H. Nakanishi E. Nobuyama Department of Information and Computer Sciences Faculty of Engineering Chiba University Inage Chiba Japan Department of Control Engineering and Science Kyushu Institute of Technology Fukuoka Japan

We extend the framework of continuous time deadbeat control, which is given by Nobuyama et al. to multi-constraints control in time and frequency domains for continuous time MIMO systems. Two conditions for the free parameter of H/sub /spl infin// suboptimal controllers are shown, which correspond to a deadbeat control interpolation condition and H/sub /spl infin// norm constraint. By restricting modified free parameters of H/sub /spl infin// controllers to commensurate time delay functions, we give all controllers which satisfy the two conditions simultaneously. Moreover, we show that time domain constraints of L/sub 2/ or L/sub 1/ norms are also reduced to finite dimensional convex problems and these mixed problems can be solved numerically.

关键词： control systems MIMO Interpolation Continuous time systems Strain control Transfer functions control engineering Delay effects Error correction Servomechanisms

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Digital Adaptive Motion control for a Servo Mechanism

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IFAC Proceedings Volumes 1997年第11期30卷 323-328页

作者： T. Suehiro F. Ohkawa T. Hokamura S. Sagara Electronics Division Mechanics & Electronics Research Institute Fukuoka Industrial Technology Center 3-6-1 Norimatsu. Yahatanishi-ku Kitakyushu-shi 807 Japan Department of Control Engineering and Science Faculty of Computer & System Engineering Kyushu Institute of Technology lizuka 820 Japan Department of Control Engineering Faculty of Engineering Kyushu Institute of Technology Tobata Kitakyushu 804 Japan

This paper is concerned with an application of a digital adaptive control system to a servo mechanism. Mechanical systems in general include nonlinearities and additional uncertainties and which result from inertia and friction. So it is difficult to ensure robust performance and high accuracy for motion control. The digital adaptive control system presented here is considered to overcome the above stated problem. Experimental results from a feed drive system demonstrate the effectiveness of the proposed control scheme.

关键词： Adaptive control Servomechanism Nonlinearity Uncertainty Friction

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Fault detection filter for linear time varying systems: An algebraic-geometric approach 4

Fault detection filter for linear time varying systems: An a...

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4th European control Conference, ECC 1997

作者： Szigeti, F. Bokor, J. Edelmayer, A. Tarantino, R. Department of Control Engineering Faculty Universidad de los Andes Mérida5101 Venezuela Systems and Control Laboratory Computer and Automation Institute Hungarian Academy of Science XI Kende u. 13-17 BudapestH1111 Hungary Maraven Oil Refinery Punta Cardon Venezuela Universidad de Los Andes Mérida5101 Venezuela

ISBN: (纸本)9783952426906

In this paper we consider the fault isolation problem for the linear time varying systems. Our approach is based on characterization of the observability of LTV systems by Kalman's rank condition, which permits us to design fault detection filters, feeding also the derivatives of the inputs and the outputs. We prove, using a computable method, that the isolation problem can be solved by generalized Luenberger's observer if and only if the detectability and the weak separability of fault signatures holds.

关键词： Observability

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Overview, current trends and latest results in estimating the effects of load modelling on power-system damping and stability

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EUROPEAN TRANSACTIONS ON ELECTRICAL POWER 1997年第2期7卷 107-113页

作者： Milanovic, JV [?]Jovica V. Milanovic (1967) received the Dipl.-Ing. (Elec.) and M.Sc. (Elec. Eng.) degrees from the University of Belgrade. Yugoslavia. in 1987 and I99 I respectively. One year he worked with “Energoproject-MDD”- Engineering and Contracting Co. in Belgrade as an engineer in designing power plants and substations. In late 1988 hejoined the Faculty of Electrical Engineering of the University of Belgrade first as an associate teaching assistant and then (since late 199 I) as teaching assistant at the Dept. of Power Converters and Drives. Between March 1993 and January 1996 he completed his Ph.D. at the University of Newcastle. Australia. at the Dept. of Electrical and Computer Engineering. Since February 1996 he is lecturer at the Department of Electrical Engineering and Computer Science at the University of Tasmania Austnlia. His major interests include synchronous machines and power system transients control and stability. (The University of Tasmania. Dept. of Electrical Engineering and Computer Science GPO Box 252-65 Hobart Tas 7001 Australia.Te1+61 362/262-753 Fax+61 369/262 136. e-mail: Jovica.Milanovic@eecs.utas.edu.au)

The paper presents the overview of load modelling for power-system damping and stability studies with main conclusions summarized from previous research. The attempt has been made to present a cross-section of the most exploited existing load models together with the most important conclusions drawn from their implementation in power-system stability programs. The current trends and latest results in the domain of damping of electromechanical oscillations in power systems are also presented. The effects of load dynamics on damping of electromechanical oscillations were analyzed on the basis of one of generic load models proposed in the past. The recent results further encourage investigation in this area and highlights the importance of proper load modelling.

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computer Aided control Systems Design for Hydraulic Drives

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IFAC Proceedings Volumes 1997年第4期30卷 359-364页

作者： B. Stein E. Vier Department of Mathematics and Computer Science (Prof. Dr. H. Kleine Büning) Knowledge-based systems University of Paderborn D-33104 Paderborn Germany. Phone: +49 (5251) 60 - 3348 Fax: +49 (5251) 60 - 3338 Department of Measurement and Control (Prof. Dr.-Ing. H. Schwarz) Faculty of Mechanical Engineering University of Duisburg D-47048 Duisburg Germany. Phone: +49 (203) 379 - 1583 Fax: +49 (203) 379 - 3027

The design of hydraulic control systems is a complex and time-consuming task that, at the moment, cannot be automated completely. Nevertheless, important design subtasks like simulation or control concept selection can be efficiently supported by a computer. Prerequisite for a successful support is a well-founded analysis of a hydraulic system's structure. The paper in hand contributes right here. It provides a systematics for analyzing a hydraulic system at different structural levels and illustrates how structural information can be used within the design process. A further central matter of this paper is the automatic extraction of structural information from a circuit diagram by means of graph-theoretical investigations.

关键词： Algorithms and Knowledge-based Software Tools for CACSD Structural Analysis of Hydraulic Systems Graph Theory

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Developing a prototype concurrent design tool for composite topside structures

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NAVAL ENGINEERS JOURNAL 1997年第3期109卷 279-290页

作者： Dirlik, S Hambric, S Azarm, S Marquardt, M Hellman, A Bartlett, S Castelli, V Steve Dirlik:began his career at the Naval Surface Warfare Center Carderock Division in 1981 as an aerospace engineer co-op student. He completed his bachelor of science degree in aeropace and ocean engineering from Virginia Polytechnic Institute and State University in 1985 and his master of science degree in aerospace engineering from the University of Maryland in 1990. Mr. Dirlik recently completed a master of science program in applied physics at The Johns Hopins University and currently works in the Radar Cross Section and Target Physics Branch of the Signatures Directorate at the Naval Surface Warfare Center Corderoke Division. He has worked on Navy low observable programs since 1990. Stephen Hambric:is a research associate at the Applied Research Laboratory at The Pennsylvania State University. He received his B. S. and M.S. degree in mechanical engineering from Virginia Polytechnic Institute and State University and his D. Sc. in mechnical engineering from the George Washington University. He has worked on several computer aided multidiscikplinary design and optimization projects over the years including an automated propeller design system and a structural acoustic optimization capability. Dr. Shpour Azarm:is currently working as an associate professor with the Design and Manufacturing Group of the Department of Mechanical Engineering at the University of maryland at College Park. Dr Azarm's expertise is in the areas of optimization-based designed and concurrent design and optimization of multidisciplinary systems. He was a consultant at Black & Decker Corporation (summer 1996) and worked as a Navy senior summer faculty fellow (summer 1995) and a NASA summer faculty fellow (summer 1994). He was a visiting scientist at NASA Langley Research Center for Multidisciplinary Analysis and Applied Structural Optimzatiom at the University of Siegen in Germany (spring 1992) and the Design Institute of the Technical University of Denmark (summer 1990). Dr Azarm was an associate technical editor of the ASME Jour

A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent engineering of Layered Structures, provides designers with an immediate assessment of the impacts of their decisions on several disciplines which are important to the performance of a modern naval topside structure, including electromagnetic interference effects (EMI), radar cross section (RCS), structural integrity, cost, and weight. Preliminary analysis modules in each of these disciplines are integrated to operate from a common set of design variables and a common materials database. Performance in each discipline and an overall fitness function for the concept are then evaluated. A graphical user interface (GUI) is used to define requirements and to display the results from the technical analysis modules. Optimization techniques, including feasible sequential quadratic programming (FSQP) and exhaustive search are used to modify the design variables to satisfy all requirements simultaneously. The development of this tool, the technical modules, and their integration are discussed noting the decisions and compromises required to develop and integrate the modules into a prototype conceptual design tool.

关键词： Warships

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Prediction of time series by a structural learning of neural networks

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FUZZY SETS AND SYSTEMS 1996年第2期82卷 167-176页

作者： Ishikawa, M Moriyama, T Department of Control Engineering and Science Faculty of Computer Science and Systems Engineering Kyushu Institute of Technology 680-4 Kawazu Iizuka Fukuoka 820 Japan

There have been numerous methods for learning and predicting time series ranging from the traditional time-series analyses to recent approaches using neural networks. A central issue common to all of them is the determination of model structure. Both mean prediction error and An Information Criterion (AIC) are useful in model selection;the model with the smallest mean prediction error or AIC is selected from among a set of models as the best one. In this way they give a solution to the problem of model selection. Due to huge search space, however, the mean prediction error or AIC alone is not powerful enough to find the best model structure from among all the candidates. In the present paper the authors propose to use both a structural learning with forgetting and the mean prediction error or AIC to find a model with better generalization ability. Jordan networks and buffer networks, popular in the modeling of time series, are examined in this paper. The structural learning with forgetting and backpropagation (BP) learning are applied to compare the learning and prediction performance of these two types of models. Simulation results demonstrate that the structural learning with forgetting has better generalization ability than BP learning both in Jordan networks and buffer networks.

关键词： neural networks model selection learning time series prediction

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