This contribution deals with the application of computer algebra based methods to the analysis of dynamic systems described by implicit ordinary differential equations. This type of system defines a submanifold of a c...
This contribution deals with the application of computer algebra based methods to the analysis of dynamic systems described by implicit ordinary differential equations. This type of system defines a submanifold of a certain jet space. We solve the problem whether this submanifold admits a parametrization by an explicit system, i.e. any solution of the original system is a solution of the explicit one and vice versa. Since this approach requires the formal integrability of the implicit system, a sketch of an algorithm for the computation of the formally integrable system is presented.
This contribution is concerned with the nonlinear controller design for a certain class of PWM (pulse width modulation) – controlled converter systems. It will be shown that under certain assumptions the SSA (state s...
This contribution is concerned with the nonlinear controller design for a certain class of PWM (pulse width modulation) – controlled converter systems. It will be shown that under certain assumptions the SSA (state space averaging) – model of the PWM–controlled converter with the duty ratio as the plant input has a very special mathematical structure. Based on this mathematical model a modified version of the nonlinear H 2 –design where an integral term is systematically included in the nonlinear controller will be presented.
Walking mechatronic systems protected much better the environment when their contact with the soil is discrete, a fact that limits appreciately the area that is crushed. In order to make and to control a walking robot...
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Walking mechatronic systems protected much better the environment when their contact with the soil is discrete, a fact that limits appreciately the area that is crushed. In order to make and to control a walking robot, one needs the knowledge of all walking potentialities since the choice of the number of legs as well as of their structures depend on the type of gait that has been selected. In the Mobil Robots Laboratory of the POLITEHNICA University of Bucharest, a four-legged modular mechatronic system has been built and tested, while a hexapod one is being tested.
作者：
CHITRE, DMSHYY, DJEPHREMIDES, AGUPTA, SCOMSAT Laboratories
22300 Comsat Drive Clarksburg MD 20871–9475 USA. Received his B.Sc. from the University of Bombay
India an M.A. in mathematics from the University of Cambridge
U.K. and a Ph.D. in physics from the University of Maryland. He is currently an Associate Executive Director of the Network Technology Division at COMSAT Laboratories. He has been involved in research and development activities in ISDN
VSAT networks data communications and network systems and architectures. Prior to his current positions Dr. Chitre was a Principal Scientist in the Network Technology Division at COMSAT Laboratories. Dr. Chitre joined COMSAT Laboratories in 1980. He has made major contributions to the analysis and architecture of data communication ISDN and BISDN via satellite. Dr. Chitre directs and participates in the international and national standards activities in ISDN BISDN and data communication as they apply to satellite communication. He was Chairman of the Working Group on Protocols and Network Timing Function of the CCIR/CCITT Joint Ad Hoc Group on ISDN/Satellite Matters during 1990–1992. Currently he is the Chairman of the Working Group on New Technologies in the ITU Intersector Coordinating Group (ICG) on Satellite Matters. Dr. Chitre was a programme manager during 1990 and 1991 on a contract from INTELSAT on systems studies on satellite communications systems architectures for ISDN and broadband ISDN systems. Currently he is the technical manager of the DoD Contract on ATM via satellite demonstration and the programme manager for the INTELSAT contract on analysis and top-level specification of INTELSAT ISDN subnetworks and SDH compatible transport network. Received the B.S. degree in electrical engineering from national Chiao-Tung University
Hsin-Chu Taiwan in 1983 and the M.S. and Ph.D. degrees in electrical engineering from Georgia Institute of Technology Atlanta GA in 1986 and 1990 respectively. From June 1987 to October 1987 he worked for the Department of Neurology Emory Univers
The role of satellite communications in networks that provide new services, such as frame relay and multimedia, is investigated. Both passive and active (on-board switching/processing) satellite systems are considered...
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The role of satellite communications in networks that provide new services, such as frame relay and multimedia, is investigated. Both passive and active (on-board switching/processing) satellite systems are considered. Novel techniques are developed for each system to demonstrate, via detailed analysis and simulation, how the communications bandwidth agility of multipoint/broadcast satellite channels, and the on-board switching/processing, makes it feasible to provide these new services via hybrid satellite and terrestrial networks in a resource-efficient manner.
This paper proposes a methodology of combining eigenstructure assignment, feedforward gain with sliding mode control technique to realize an enhanced robust pitch pointing flight controlsystem. This controlsystem ca...
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This paper proposes a methodology of combining eigenstructure assignment, feedforward gain with sliding mode control technique to realize an enhanced robust pitch pointing flight controlsystem. This controlsystem can track step input commands without error and it turns out to be consistently robust against parameter variations and external disturbances. The design methodology is illustrated by application to an AFTI/F-16 aircraft.
As part of a program to develop reverse osmosis (RO) desalination systems for shipboard freshwater production, the David Taylor Naval Ship Research and Development Center worked with the Naval Sea systems Command to i...
As part of a program to develop reverse osmosis (RO) desalination systems for shipboard freshwater production, the David Taylor Naval Ship Research and Development Center worked with the Naval Sea systems Command to install a 12,000 gal/day, two-stage RO plant aboard USS Fletcher (DD 992) in 1981. The first stage provides potable water (less than 500 parts/million total dissolved solids) for crew needs; the second stage provides high purity water (less than 2 parts/million of total dissolved solids) for boiler makeup. The plant has been producing acceptable water quality and quantity despite some materials related problems. The system design has proven to be well suited for minimizing manning and maintenance requirements. A 12,000 gal/day “ship quality” RO system is now under contract to meet Navy needs for a reliable, minimum weight and volume, low energy desalination plant for future surface ships. The preproduction plant will be required to meet stringent reliability requirements as well as shock, vibration, and noise specifications as part of the process for obtaining approval for full production. This paper describes the technology developments necessary to achieve the present naval performance levels and discusses plans for future applications.
作者：
LUEDEKE, GFARNHAM, RBJR.George Luedeke
Jr.: received his BS degree in Mechanical Engineering from Massachusetts Institute of Technology and his MS degree in Product Design from Illinois Institute of Technology. Early in his career Mr. Luedeke joined General Motors Corporation as a designer responsible for development of people mover and rail rapid transit systems. From 1964 to 1974 he was with Hughes Aircraft Company. At Hughes he performed analyses and developed designs for a wide variety of program and proposal efforts such as: High Speed Ground Transportation (DOT) Task Force Command Center (NAVY) Panama Canal Marine Traffic Control Center (Panama Canal Co.) Royal Iranian Navy Command Center (Iran) Tactical Information Processing and Interpretation Center (Air Force) and WALLEYE CONDOR and PHOENIX Missile Systems (NAVY). He also had marketing development responsibilities related to the diversification of Hughes resources in civil business areas such as: Automatic train control (WMATA BARTD SCRTD) water/sewage treatment plant automation (Santa Clara County) Aqueduct Control (SWR) Hydrometeorological data collection (BPA WMO) and Salton Sea basin systems analysis (Dept. of the Interior). He was responsible for combat system integration for the Hughes 2000T Surface Effect Ship (SES) proposal. He also conducted detailed studies concerning ship flexure for the Improved Point Defense Target Acquisition System Program and for the definition of operational High Energy Laser weapon installations on a series of conventional monohulls (DLG DD and CVN). Since 1974 Mr. Luedeke has been employed at RMI Inc. (formerly Rohr Marine Inc.). During this time he has held several positions. His responsibilities have included directing a number of studies on advanced SES concepts managing activities defining mission/cost effectiveness of military and commercial SES's including defining the operational benefits and enhanced survivability characteristics of cargo SES's for high speed military sealiftfor NA TO and Southeast Asia
This paper will present the results of a marketing, engineering, and economic analysis of advanced marine vehicles done by IMA Resources, Inc. and RMI, Inc., in support of a Maritime Administration project to study “...
This paper will present the results of a marketing, engineering, and economic analysis of advanced marine vehicles done by IMA Resources, Inc. and RMI, Inc., in support of a Maritime Administration project to study “Multimode Express Shipping”. The study was conducted in 1981 and examined the economic benefits of using advanced marine vehicles as express cargo vessels in domestic and international service. Commodity characteristics, desirable express carrier rates, and potential high payoff service and route alternatives were identified. Advanced marine vehicles were surveyed and sized to meet desirable deadweight and block speed objectives. The costs of operating these craft on a variety of trade routes were calculated using an advanced marine vehicle economic analysis program. Revenues, expenses, break-even, profit and loss, cash flow requirements, tax summary and economic indicators (i.e., cost/ton – mile, etc.) were projected over the expected life of the vehicles as was return on investment. Traffic density and market penetration considerations narrowed the field of choice to smaller sized advanced marine vehicle carriers (i.e., 50 and 250 ton deadweight) and to three international and five domestic routes.
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