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American control Conference (ACC)

作者： Charles E. Rohrs Gunter Stein Karl J. Astrom Department of Electrical Engineering University of Notre Dame Notre Dame IN USA Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA Systems and Research Center Honeywell Inc. Minneapolis MN USA Department of Automatic Control Lund Institute of Technology Lund Sweden

The recently obtained evidence of the need for a positive real element in an adaptive system leaves us with a disturbing gap in adaptive control theory. It is a fact that in some applications adaptive controllers are performing well in practice. How can these systems behave well in practical situations which must contain modeling error? This paper introduces a preliminary result which indicates that it may be possible to maintain the needed positive real system in the presence of modeling error. The result shows that if a continuous-time system with large high frequency uncertainty is treated appropriately with antialiasing filters and sampled slowly enough, the resulting discrete-time system may contain very little uncertainty. With small enough uncertainty in the plant, a positive real system in the adaptive loop is possible.

关键词： Uncertainty Adaptive control Adaptive systems Programmable control Filters Stability Sampling methods Frequency response Adaptive algorithm Sampled data systems

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A Practical Robustness Theorem for Adaptive control

A Practical Robustness Theorem for Adaptive Control

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American control Conference (ACC)

作者： Charles E. Rohrs Gunter Stein Karl J. Astrom TelLaboratories Research Laboratory South Bend IN and Department of Electrical Engineering University of Notre Dame Notre Dame IN USA Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA USA Systems and Research Center Honeywell Inc. Minneapolis MN USA Department of Automatic Control Lund Institute of Technology Lund Sweden

In this paper, two theorems are quoted which, when applied together, provide much information about the robustness of adaptive control schemes. From these two theorems, another theorem is developed which can explain why adaptive controllers can perform robustly in certain practical situations, while possibly failing in other situations. In particular, if the bandwidth constraints on a control systems are lenient enough to allow the use of a sampling frequency which is smaller than the frequency at which unstructured uncertainty becomes significant, an adaptive controller can behave robustly. Many, if not all, of the applications of adaptive control which have been successful employ relatively slow sampling of the process. Thus, the results of this paper provide a theoretical explanation of how certain adaptive controllers are performing robustly in practice. In addition, the final theorem is of a form which provides insight into what a priori knowledge is required to achieve robust adaptive control and how this knowledge say be used.

关键词： Robust control Adaptive control Uncertainty Frequency Sampling methods Programmable control control systems Transfer functions Automatic control Bandwidth

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AN APPROACH TO NONLINEAR FEEDBACK-control WITH APPLICATIONS TO ROBOTICS

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IEEE TRANSACTIONS ON systems MAN AND CYBERNETICS 1984年第6期14卷 879-884页

作者： GILBERT, EG HA, IJ Department of AeroSpace Engineering Robot Systems Division University of Michigan Ann Arbor MI USA Computer Information and Control Engineering Program Robot Systems Division College of Engineering University of Michigan Ann Arbor MI USA

A control problem involving a mechanical system with generalized coordinates q ∈ R m is considered. The error in tracking a desired input y d ∈ R p is e = E (q,y d )∈ R m . If E satisfies simple conditions, it leads to a nonlinear control law that assures e (t)→0 as t →∞. The law is robust in that small changes in it do not produce large steady-state errors or loss of stability. In this theory a unified framework is presented for treating a number of problems in the control of mechanical manipulators.

关键词： Manipulators Measurement uncertainty Vectors Joints Approximation methods Feedback control

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Comparative evaluation of a new procedure for adaptive estimation of noisy images

Comparative evaluation of a new procedure for adaptive estim...

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Zhang Pu H. Kaufman Beijing Institute of Information and Control Beijing China Electrical Computer & Systems Engineering Department Rensselaer Polytechnic Institute Troy NY USA

A new iterative adaptive image restoration algorithm is developed. It is composed of a sub-optimal filter and a least squares based identifier. To account for nonstationarity, a moving window technique has been incorporated. Based upon computational results on two noisy images and a comparison with three other adaptive image restoration algorithms, it was concluded that the proposed adaptive image estimation algorithm is highly competitive.

关键词： Adaptive estimation Autoregressive processes Image restoration Iterative algorithms Filters Mathematical model Pixel Equations Least squares methods Interpolation

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Large Scale systems Applications

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IFAC Proceedings Volumes 1984年第2期17卷 1235-1242页

作者： M.G. Singh M.S. Mahmoud M.F. Hassan Control Systems Centre UMIST P.O. Box 88 Manchester M60 1QD UK Electrical and Computer Engineering Department Kuwait University P.O Box 5969 Kuwait Electronics and Communication Engineering Department Cairo University Giza Egypt

An overview of system applications using large-scale modelling, optlmlsation and control methods is presented. The method used includes both hierarchical and dec entralised control. The applications are drawn from the fields of power systems, biological processes, water distribution networks, urban traffic control, telecommunication networks, river pollution control and a ship system.

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The Impact of Microcomputers on Society

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IFAC Proceedings Volumes 1984年第2期17卷 3519-3519页

作者： Naresh K. Sinha T. Vamos Fred Marguiles Madan M. Gupta Department of Electrical and Computer Engineering McMaster University Hamilton Canada Computer & Automation Institute Budapest Hungary Vienna Technical University Vienna Austria Systems and Adaptive Control Laboratory University of Saskatchewan Saskatoon Canada

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THE NO FRAME CONCEPT - ITS IMPACT ON SHIPYARD COST

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NAVAL ENGINEERS JOURNAL 1984年第3期96卷 218-232页

作者： NAPPI, NS WALZ, RW WIERNICKI, CJ Natale S. Nappi:graduated from City College of New York in 1954 with a B.S. degree in civil engineering and received his M.S. in civil engineering from the Polytechnic Institute of Brooklyn in 1959. He began his professional career in 1954 at the New York Naval Shipyard as a naval architect (structures) performing detail structural design and fabrication studies for CVAs LPDs DDs and CGs and eventually became a supervisory naval architect (structures). From 1965 to 1973 he was a member of the staff of the Computer-Aided Design Division at the David Taylor Naval Ship Research and Development Center (DTNSRDC). As such he was involved in the development of the computer structural design tool the SSDP (in association with Frank M. Lev) and automated detail design programs (CASDOS). His current position is Senior Naval Architect Consultant in the structural integrity group of the Ship Structures Division Structures Department DTNSRDC. Mr. Nappi is the author and co-author of numerous technical papers and reports covering a wide spectrum of topics such as automated structural design process design for producibility and survivability material weight and cost trade-off studies and structural weight determination for high performance ships (i.e. SES SWATH HYSWAS). He has lectured on the subjects of design for survivability and ship structures at the Naval Post Graduate School and MIT. He is a member of ASNE ASCE U.S. Naval Institute Sigma Xi and is a registered Professional Engineer in the State of New York. Mr. Nappi was a member of the NAVSEA working commitee for the computer supported design planning effort and is currently a member of the DTNSRDC ASSET Advisory Committee. Ronald W. Walz:graduated in 1974 from Pennsylvania State University with a B.S. degree in civil engineering. He began his professional career in 1974 at the David Taylor Naval Ship Research and Development Center as a structural engineer in the structural design concepts group of the Ship Structures Division Structures Department.

A proposed cost effective alternative to current U.S. Navy structurally configured hulls is presented in this paper. This proposed design for producibility concept involves the elimination of structural stanchions and transverse web frames. The potential impact of this “no frame” concept on structural design, weight and construction and material costs for naval surface frigates and destroyers is reflected in 1) reduced costs for the installation of distributive systems and 2) a reduced number and complexity of structural details providing a more reliable and less costly structure. This study was performed in three parts: 1) Determine the most feasible length between bulkheads without frames; 2) Using this length perform detail weight studies and construction and material costs analysis comparison on a 72-foot long hull module, with and without frames, for a FFG-7, and 3) Estimate the saving in man hours of labor on the installation of distributive systems and shipfitting for an FFG-7. For the feasible length studies on the “no frame” structural configuration, thirty-seven strength, weight and vertical center of gravity studies were performed on two ship classes; twenty-two on the FFG-7 class and fifteen on the DD-963 class. The detailed weight studies and construction and material cost analyses were conducted for FFG-7 “no frame” and “as built” modules. Results indicating the “no frame” concept module was 6.8% heavier and 14.8% less costly than the “as built” module. For the impact of an FFG-7 “no frame” structurally configured hull on the cost of labor required for the installation of distributive systems and for other functional work such as ship fitting, welding, and electrical, this study indicated a reduction of 169,206 labor hours per ship, representing 7.12% of the total required man hours to fabricate an FFG-7 class ship. With the employment of the “no frame” concept, certain areas of significant concern and potential risk were addressed. These include: 1) t

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DESIGN FOR NEW-JERSEY, IOWA, AND DES-MOINES MODERNIZATION

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NAVAL ENGINEERS JOURNAL 1984年第3期96卷 25-38页

作者： SIMS, PJ EDWARDS, JR DICKEY, RL SHULL, HS Philip J. Sims:graduated from Webb Institute in 1971 and went to work for the Advance Design Branch of the Naval Ship Engineering Center. He was part of the FFG-7 design team in 1972. The 1973–75 years were spent developing automated early-stage aircraft carrier design procedures and performing carrier design trade-off work in support of the CVV design. He returned to school in 1976 for a masters at M.I. T. The 1977–80 period was spent updating the Navy's destroyer-cruiser early-stage design procedures and performing studies for the CGN-42 reserve FFX and DDX (later DDG 51) projects. Also during this period he was team leader on concept formulation (CONFORM) studies of new ships such as a heavy combatant and a low detectability ship. From 1981 to early 1983 Mr. Sims was Design Integration Manager for the BB-62 and Ship Design Manager for the BB-61 and CA-134. He is presently principal naval architect for the FFX study and also works on the NA TO frigate effort. James F. Edwards Sr:.is the Technical Director Ship Analytics Inc. Washington D.C. Operations and was the Ship Design Manager for the battleship USSNew Jerseyprior to his departure from NAVSEA in August 1983. He joined the U.S. Navy Reserves in 1954 and served on active duty from 1957 to 1960. From 1961 to 1963 he worked for McLaughlin Research Corporation as a section head in the drafting department. From 1963 to 1966 he worked for the Vitro Corporation of America in the Terrier (surface missile systems) Department. In 1966 he participated in the contract design of the first shipboard integrated digital ASW Command and Control system while working for the Stanwick Corporation. In 1967 Mr. Edwards accepted a position at NAVSHIPS in the Combat System Integration Division. In 1974 he transferred to what is currently NAVSEA's Hull Design Division. In 1980 Mr. Edwards was designated as the Battleship and Heavy Cruiser General Arrangements Task Leader and subsequently served as the Hull Task Group Manager the Ship Configuration Control Manager and fina

In reactivating the battleship New Jersey , the Navy faced three major problems. The baseline data on the ship was not readily available or reliable, a new generation cruise missile armament was proposed, and the ship delivery schedule was very tight. After doing a feasibility study, system design engineers were taken onboard the mothballed ship to resolve the design problems. Being on the ship allowed an intensive effort and immediate reference to the actual ship configuration. The tools used to control this effort were a ship check plan, a ship check form and the master arrangement drawing. Simultaneously with the design effort, a repair scoping effort was conducted. The design evolution and solutions to the major problems are described. The results of the New Jersey effort are shown with sample documentation, the ship characteristics and the downstream design effort. The Iowa was the next ship to be modernized. The top level requirements were the same as New Jersey's but new problems were encountered. More options were investigated which diverted attention from the basic effort. A fundamental difference was the Iowa had not had a 1968 reactivation as the New Jersey had, so items that were repair and reactivation on the New Jersey in 1968 had to be part of the Iowa modernization. A major influence on the Iowa design process was that a complete set of specifications for a private yard bid had to be developed. The next effort was to install the same New Jersey modernization payload on a Des Moines class heavy cruiser. Heavy cruisers are large ships but significantly smaller than battleships and much closer to their naval architectural limits of weight and center of gravity. They have much less topside area than the battleships, and the new payload was very topside space consuming. The cruisers are also much more restricted in internal volume. Two feasibility studies were conducted. One resolved volume problems but approached the weight and center of gravity limits.

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AN ADVANCED METHODOLOGY FOR PRELIMINARY HULL FORM DEVELOPMENT

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NAVAL ENGINEERS JOURNAL 1984年第4期96卷 147-161页

作者： LIN, WC DAY, WG HOUGH, JJ KEANE, RG WALDEN, DA KOH, IY Wen-Chin Lin:heads the Ship Powering Division at the David Taylor Naval Ship R&D Center (DTNSRDC). Dr. Lin received his B.S. degree in mechanical engineering from the National Taiwan University in 1957. He was awarded his M.S. degree in naval architecture and Ph.D. in engineering science from the University of California at Berkeley in 1963 and 1966 respectively. From 1966 to 1969 he was employed by ESSO Research and Engineering Company to conduct marine hydrodynamic research for oil tankers and offshore structures. Since joining DTNSRDC in 1969 he has actively conducted and directed hydrodynamic research to advance naval ship design technology and improve ship performance. Active in national and international symposia on ship hydrodynamic research he is recognized for contributions to the ship research community. For the past six years he has been a member of the Performance Committee of the ITTC and currently serves as secretary of the committee. He is a member of SNAME and the Society of Naval Architects of Japan. William G. Day Jr:. has been employed as a naval architect at the David Taylor Naval Ship R&D Center since receiving a B.E.S. degree from the Johns Hopkins University in 1966. He obtained an M.S. E. degree from George Washington University in 1971. As Head Design Evaluation Branch of the Ship Performance Department he is responsible for model experiments to evaluate the hydrodynamic performance of ships and propulsors. He is a member of ASNE and SNAME. In-Young Koh:received his B.S. and M.S. degrees in electrical engineering from Lowell University in 1969 and 1971 respectively and his Ph.D. in applied mechanics from Rensselaer Polytechnic Institute in 1976. Dr. Koh joined DTNSRDC as an electronic engineer specializing in the application of advanced instrumentation and computer techniques to ship research and design. He is currently engaged in research and development of active control systems for naval ship applications. Dr. Koh is a member of ASNE SNAME and IEEE. David Andrew Walden:is

A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeeping-optimized hull form without making concessions to other performance considerations, such as resistance. The seakeeping-optimized hull is then modified to improve other performance characteristics without degrading the seakeeping. Presented is a point-design example produced by this methodology. Merits of the methodology and the point design are assessed on the basis of theoretical calculations and model experiments. This methodology is an integral part of the Hull Form Design System (HFDS) being developed for computer-supported naval ship design. The modularized character of HFDS and its application to hull form development are discussed.

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Development of an interactive graphical user interface for the UMIST control design suite

Development of an interactive graphical user interface for t...

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IEEE Conference on Decision and control

作者： Dean K. Frederick Neil Munro Peter Putz Dieter Platzer Electrical Computer and Systems Engineering Department Rensselaer polytechnic Institute Troy NY USA Control Systems Centre UMIST (University of Manchester Institute of Science and Technology) Manchester UK

A collaborative effort has been undertaken at both UMIST and Rensselaer to use interactive computer graphics to develop an improved user interface for the UMIST suite of programs for performing analysis, design, and synthesis of control systems. The objective is to explore ways in which presently available and newly emerging interactive graphics terminals can be employed with this specific suite and with control design packages in general. This paper is a presentation of the plans for this project and a report on its progress to date.

关键词： Graphical user interfaces control design User interfaces

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