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Fuzzy-Type Objective Functions for NNDC

IFAC Proceedings Volumes 1998年第12期31卷 127-132页

作者： Andreas E. Kanarachos Kleanthis T. Geramanis National Technical University of Athens Department of Mechanical Engineering Mechanical Design & Control Systems Division Polytechnic Campus Zografou P. O. Box 64078 15710 Greece

In this paper a "fuzzy-type" objective function is proposed for the training of Neural Network Direct controllers (NNDC). The proposed method is based on cumulative evaluation of system's performance while the objective function seeks to minimize the "equivalent" system error, determined by fuzzy-set theory. The fuzzy-type objective function promises to increase convergence speed and performance of the NNDC. A successful application with respect to the robust control of a nonlinear dynamic system reveals a new approach for improved neural network capabilities extended by fuzzy logic theory.

关键词： Closed-loop control Dynamic systems Feedforward networks Fuzzification Fuzzy models Nonlinear systems Robust control

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design and Evaluation of the Human-Machine Interface for Inspection Tasks of a Teleoperated Space Manipulator

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IFAC Proceedings Volumes 1998年第26期31卷 335-340页

作者： E.F.T. Buiël M. de Beurs A. van Lunteren B.G. Stassen Delft University of Technology Faculty of Design Engineering and Production Department of Mechanical Engineering and Marine Technology Man-Machine Systems and Control Group Mekelweg 2 2628 CD Delft the Netherlands

The anthropomorphic European Robotic Arm (ERA) is a large telemanipulator that will be mounted on the new International Space Station. To the human operator, the execution of ERA's inspection tasks is difficult because of the lack of spatial information in the available camera pictures, the manipulator dynamics, and the potential presence of time delays in the control loop. The humanmachine interface must assist the operator in order to avoid collisions between the manipulator and hazardous objects in its environment. The results of simulator experiments with three different configurations of ERA's human-machine interface show that automatic collision avoidance as well as a perspective distance visualisation in a graphical camera overlay are indispensable components of the interface. The automatic collision avoidance decreases the task completion time. Besides, it releases the operator from frequently correcting the commanded movements. The perspective graphical camera overlay substantially improves the operator's situational awareness. As a result, the automatic collision avoidance has to correct his control commands less often.

关键词： teleoperation manual control human-machine interface human-centred design evaluation

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Position-based impedance control using fuzzy environment models

Position-based impedance control using fuzzy environment mod...

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SICE Annual Conference

作者： F. Nagata K. Watanabe K. Sato K. Izumi Interior Design Research Institute Fukuoka Industrial Technology Center Fukuoka Japan Department of Advanced Systems Control Engineering Graduate School of Science and Engineering Saga University Saga Japan Department of Mechanical Engineering Faculty of Science and Engineering Saga University Saga Japan

Impedance control is one of the most effective force control methods for a robot manipulator in contact with an object. It should be noted, however, that a practical study on such a method has not been successfully applied to an industrial robot with 6 degree-of-freedom. A hybrid compliance/force control (HCC) in this field was suggested to deal with the practical problem, in which a desired damping coefficient is determined by repeating many simulations. To determine a suitable compliance without trial and error, we have already presented a tuning method which produces the desired time-varying compliance, giving the critical damping in contact with an object, by using the information on the inertia and Jacobian matrices. But the tuning method needs to measure the physical information of the environment. In this paper, to overcome the problem we propose a fuzzy environment model that can estimate each directional stiffness of the environments. The fuzzy environment model is composed of several fuzzy rules which are learned with genetic algorithms. Simulation results show that the proposed method is very effective for deciding the desired compliance without any complicated tuning and is very robust to the change of environment.

关键词： Impedance Fuzzy control Force control Service robots Tuning Damping Industrial control design engineering Manipulators Jacobian matrices

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Modeling of multiple mobile manipulators handling a common deformable object

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Journal of Field Robotics 1998年第11期15卷

作者： Herbert G. Tanner Kostas J. Kyriakopoulos N. J. Krikelis Control Systems Laboratory Department of Mechanical Engineering Division of Machine Design and Control National Technical University of Athens Athens 10682 Greece

The dynamic equations of motion for a system of multiple mobile manipulators carrying a common deformable object are developed. The derived centralized model is based on Kane's approach to dynamics. The imposed kinematic nonholonomic constraints are included and incorporated into the dynamics. It is pointed out, however, that these kinematic constraints are only necessary, and they only become sufficient to impose nonholonomic motion when accompanied by the dynamic counterparts. Sufficient conditions for avoiding tipping over by the mechanisms are also provided. The whole set of constraint equations is analyzed and useful properties for the set of admissible solutions for the ground reaction forces are obtained. The deformable object under manipulation is modeled and the simplest approximating grid structure is indicated. © 1998 John Wiley & Sons, Inc.

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Ship habitability - Preparing for the 21st century

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NAVAL ENGINEERS JOURNAL 1997年第6期109卷 21-27页

作者： Meere, EP Grieco, L Edward P. Meere:works in the Arrangements Division of the NavSea Systems Command (SEA 03H1) and has been the Navy Habitability Program Manager for the past three years. He received a Bachelor of Science in Engineering Science from Illinois Institute of Technology in 1966. He received a Masters of Business Administration from the American University in 1977. His experience to date includes: Mathematics teacher at Prince Georges Community College for 7 years 10 years as Branch Head for Carrier and Amphibious Arrangements Project Engineer for Underway Replenishment Equipment responsible for the concept and development of the One Man Control Station. Louis R. Grieco:is a Supervisory Mechanical Engineer in the Habitability Branch of the Hull and Deck Machinery Department at the Naval Surface Warfare Center Carderock Division Philadelphia where he has been employed since 1971. He received a Bachelor of Science in Mechanical Engineering degree from Drexel University in 1979. His experience to date includes trade design and combat systems assignments at Philadelphia Naval Shipyard from 1960 to 1971 In Service Engineering Section and Branch Head for cargo/ weapons elevators conveyors torpedo handling systems habitability equipment and underway replenishment equipment and Life Cycle Manager for habitability systems. He also serves as a member of the Industrial Advisory Board at Temple University Philadelphia PA.

This paper discusses the problems identified in a FY 1995 fleet habitability survey. The survey questioned the fleet on the quality of shipboard living and working conditions and identified shortfalls in berthing, sanitary spaces, and food service systems that influence crew morale, safety, and ultimately mission effectiveness. Existing habitability programs, new initiatives and responses to the survey problems, plus a few quality of life ideas for the 21st century, are outlined.

关键词： Warships

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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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Spline-based guidance with enhanced frequency robustness for the motion of flexible part handling manipulators

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MECHATRONICS 1996年第7期6卷 761-777页

作者： Antoniadis, I Kanarachos, A Machine Design Control Systems Section Department of Mechanical Engineering National Technical University of Athens P.O. Box 64078 Athens 15710 Greece

A new spline-based method is introduced for guiding the motion of flexible part handling manipulators. Compared to closed-loop-based control methods, it enables simplicity in the design of the manipulator and thus reduced cost and complexity. The method can be easily implemented even on existing manipulators, requiring minimal computational cost and knowledge of the dynamic parameters of the manipulator, and it is quite versatile, leading to guidance functions properly adapted to the specific manipulator requirements. However, the basic advantage of the method is the extensive robustness characteristics it offers at large payload variations and/or uncertainties of possible non-linearities of the manipulator, overcoming to a significant degree this traditional disadvantage of guidance-based methods over the methods based on closed-loop control. Copyright (C) 1996 Elsevier Science Ltd.

关键词： Manipulators

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Waterjet to Hull load transfer

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NAVAL ENGINEERS JOURNAL 1996年第3期108卷 375-383页

作者： Alexander, K [?]Dr. Keith Alexander has a background in science and teaching and earned a degree in Mechanical Engineering from the University of Canterbury in New Zealand. He completed a Ph.D. through work on a high speed craft of his own design. After leaving the University Dr. Alexander spent five years working in engineering consultancies on a variety of projects dealing with heavy industrial equipment. He returned to marine work when he joined Hamilton Jet in 1989 as the technical section manager In this position he managed the design of six new jets and control systems and established a number of research programs with the University of Cantebury and other agencies. He is currently a jet design engineer and research manager at Hamilton Jet. Dr. Alexander maintains professional memberships in ASNE MIPENZ and SNAME.

The propulsion and control loads from a waterjet must be transmitted to the craft hull. The philosophy in many waterjet installations is to carry the loads from the waterjet through the transom and into the hull. For this purpose the transom is required to be stiffened by the boat designer and builder. Recent analysis by boat builders and waterjet manufacturers has highlighted the fact that while the transom is stiff laterally so that it easily carries steering loads, it is difficult to stiffen in a fore and aft direction. By contrast the inlet ducting is stiff in the fore and aft direction. Consequently it frequently carries the major thrust loads. The problem is that the inlet ducting, in many cases, is only designed to deliver the water to the jet pump and is not intended to carry these loads. Because of this, failures can occur in the ducting and its support structure. An alternative approach is to design the ducting specifically to carry these major thrust loads. This leads to heavier ducting but lighter transom structures. In this case the loads are transferred directly to the hull bottom which is more readily stiffened to take these loads in the fore and aft direction. This paper identifies waterjet loads and moments for normal running, steering and reverse. It specifies where they act and discusses the implications with respect to the two philosophies for transmitting these loads to the boat hull. Finite element analyses for the two approaches are compared, and the critical issues identified. Conclusions are drawn from the point of view of safety, ease of duct manufacture and jet installation.

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Modeling and simulation in the sealift program

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NAVAL ENGINEERS JOURNAL 1996年第6期108卷 27-39页

作者： Edinberg, D Back, K McVeigh, J David Edinberg is a senior naval architect with Advanced Marine Enterprises in Arlington Virginia. His experience in ship design includes dynamic analysis of ship's deck systems intact and damaged stability calculations trim and stability support during ship designs and structural design. For the last two years he has led a team of engineers in the dynamic analysis of the sideport ramp system employed on the Navy's new sealift ships. He graduated in 1979 with a B.S. degree in naval architecture and marine engineering from the University of Michigan. Keith Back is a senior engineer with Advanced Marine Enterprises in Arlington Virginia. He is currently the section chief for the Advanced Visualization Group. He has more than ten years experience developing and using CAD models in the ship design environment. For the past two years he has led the development of visualization techniques and models for use in simulations for current ship design programs. He graduated in 1985 with a B.S. degree in aerospace and ocean engineering from Virginia Polytechnic Institute and State University. USA Lt. Col. Joe McVeigh USA is currently deputy program manager (Army) for PMS 385 the Strategic Sealift Office at NavSea. As the senior U.S. Army officer on staff he is responsible for interfacing with the program's primary customer in addition to his assignment as T&E director. Lt. Col. McVeigh graduated with a B.Sc. from the United States Military Academy in 1978 after which he received his 2nd lieutenant's commission in the U.S. Army Transportation Corps. In 1991 he received M.S. degrees in mechanical engineering and naval architecture and marine engineering from MIT. Lt. Col. McVeigh's previous assignments have included: platoon leader/XO 870th Terminal Transfer Company program support officer/XO/contract administrator DLA operations staff officer/Exercise Branch chief. Special Forces Europe company commander 598th Medium Truck Company commander Movement Control Team Mannheim and Army watercraft systems engineer U.S.

The Navy's Sealift Program had several unique problems associated with it which have been addressed using innovative modeling and simulation tech niques. These techniques fall under two categories: visualization and dynamic analysis. This paper will discuss the employment of these techniques and the impact their application has had in the program. Also examined will be various difficulties that were encountered in the application of these techniques. Commercial-off-the-shelf (COTS) visualization tools were used to model the interior Ro/Ro spaces on the four classes of new construction and conversion ships now being procured. These models were employed for vehicle maneuvering simulations, operator familiarization and visualization of the results of an analysis of the loading and unloading of Ro/Ro vehicles. A COTS dynamic analysis system was used to simulate dynamic behavior during the assembly/deplopment and retrieval/disassembly of the side port ramp using the ships' cranes. These analyses supported reviews of design configurations, proposed handling procedures, and in conjunction with extensive post-processing, operability assessments for system operation. In a parallel effort, an interactive crane simulator was developed to support on-going engineering studies, indoctrination, and test and evaluation purposes. Lessons learned have been applied to other activities at the Naval Sea systems Command. Critical areas were the validation and maintenance of up-to-date configuration data for the visual models, adaptive levels of detail to meet the requirements of each study objective, and the need to provide comprehensive documentation of models.

关键词： Marine engineering

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WATERJET VERSUS PROPELLER ENGINE MATCHING CHARACTERISTICS

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NAVAL ENGINEERS JOURNAL 1995年第3期107卷 129-139页

作者： ALEXANDER, K Keith Alexander:has a background in science and teaching and earned a degree in Mechanical Engineering from the University of Canterbury in New Zealand. He completed a Ph.D. through work on a high speed amphibious craft of his own design. After leaving the University Dr. Alexander spent five years working in engineering consultancies on a variety of heavy industrial equipment. He returned to marine work when he joined Hamilton Jet in 1989 as the Technical Section Manager. In this position he managed the design of six new jets and control systems and established a number of research programs with the University of Canterbury and other agencies. He is currently a jet design engineer and Research Manager at Hamilton Jet. Dr. Alexander is a member ofASNE MIPENZ and SNAME

This paper outlines the major differences between waterjets and fixed-pitch propellers in the way they absorb engine power. Some of these differences are subtle and far reaching, and have only recently come to light. They have consequences for the operator, the engine selection and the engine settings. This paper touches on the following areas: the rigid relationship between power absorption and rpm, which means the waterjet can be used as an engine dynamometer, and the contrast with propellers where rpm is related to boat speed the differences in power absorption off the match point, and the fact that the waterjet cannot overload an engine;the consequences for the operator and the engine comparisons of engine rpm with boat speed, and the propulsion power available against boat speed for waterjets and propellers the differences in power absorption characteristics with overloaded or light boats strategies used by engine manufacturers to accommodate waterjet and propeller characteristics These issues are discussed as factors which are significant in the selection of the propulsor, and are sometimes not appreciated by operators familiar with propeller driven craft.

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