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 ...
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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.
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 w...
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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.
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 seakeepin...
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.
The declining cost of computer hardware and the increasing data processing needs of geographically dispersed organizations have led to substantial interest in distributed data management. SDD-1 is a distributed databa...
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CARRUTHERS, JAMES F.CANADIAN FORCESCdr. James F. Carruthers is a native of Drumheller
Alberta Canada. He joined the Royal Canadian Navy in 1961 and attended the Royal Roads Military College from 1961 to 1963 receiving his BE degree in Electrical Engineering. Following Pre-Fleet Training he was assigned to HMCS Gatineau for watchkeeping and engineering training. Work on the prototype AN/SQS-505 Sonar ASROC Missile System and the prototype ASW Data System (ASWDS) followed including shipboard installation and evaluation of the system in HMCS Terra Nova during which time he was the “guinea pig” Combat Systems Engineer. Later during the construction phase of the Canadian Navy's Combined Support Center he acted as Principal Engineer subsequently returning to graduate studies at the Nova Scotia Technical College in 1971 from which he received his Ph.D. in Electrical Engineering designing and building a computer intended for ship machinery health monitoring in the process. Posted to Headquarters in 1974 he served as Project Officer for a mini command and control system known as ADLIPS his additional interests being that of originating plasma and digital television developments. It was during this period that the SHINPADS concept was first put forward and following a year at the Canadian Forces Command and Staff College he was promoted to his present rank in 1977 and posted as Head of the Naval Command and Control Design Authority (DCMS 7). Cdr. Carruthers is a registered Professional Engineer (Ontario). and as an author has had several technical papers published on digital design machinery health monitoring and the SHINPADS concept. At the present time he is Assistant Director Maritime Combat Systems at the National Defense Headquarters in Ottawa where his current responsibilities include all aspects of C2systems. A member of ASNE since February 1978 he is also a member of IEEE U.S. Naval Institute and the IEEE Computer Society.
The Shipboard Integrated Processing And Display System (SHINPADS) is a Canadian Forces Trademark, and is not really a system. It is rather a concept of ship integration. Not combat system integration or propulsion and...
作者:
CARRUTHERS, JAMES F.CANADIAN FORCESCdr. James F. Carruthers is a native of Drumheller
Alberta Canada. He joined the Royal Canadian Navy in 1961 and attended the Royal Roads Military College from 1961 to 1963 receiving his BE degree in Electrical Engineering. Following Pre-Fleet Training he was assigned to HMCS Gatineau for watchkeeping and engineering training. Work on the prototype AN/SQS-505 Sonar. ASROC Missile System and the prototype ASW Data System (ASWDS) followed including shipboard installation and evaluation of the system in HMCS Terra Nova during which time he was the “guinea pig” Combat Systems Engineer. Later during the construction phase of the Canadian Navy's Combined Support Center he acted as Principal Engineer subsequently returning to graduate studies at the Nova Scotia Technical College in 1971 from which he received his Ph.D. in Electrical Engineering designing and building a computer intended for ship machinery health monitoring in the process. Posted to Headquarters in 1974 he served as Project Officer for a mini command and control system known as ADLIPS his additional interests being that of originating plasma and digital television developments. It was during this period that the SHINPADS concept was first put forward and following a year at the Canadian Forces Command and Staff College he was promoted to his present rank in 1977 and posted as Head of the Naval Command and Control Design Authority (DCMS 7). Cdr. Carruthers is a registered Professional Engineer (Ontario) and as an author has had several technical papers published on digital design machinery health monitoring and the SHINPADS concept. At the present time he is Assistant Director Maritime Combat Systems at the National Defense Headquarters in Ottawa where his current responsibilities include all aspects of C2systems. A member of ASNE since February 1978 he is also a member of IEEE U.S. Naval Institute and the IEEE Computer Society.
The Automatic Date Link Plotting System (ADLIPS) about to enter production in Canada might be described as a “poor man's NTDS.” It has been designed to operate actively on both Link 11 and Link 14, integrate cur...
An empirical heuristic learning identification algorithm of Ivakhnenko was modified and used to model an environmental system producing high nitrate levels in agricultural drain water in the Corn Belt. The method amou...
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作者:
BECKER, LOUIS A.SIEGRIST, FRANKLIN I.Louis A. Becker was born in New Rochelle
N.Y. in 1930 receiving his earlier education in the New Rochelle Public Schools. He completed his undergraduate studies at Manhattan College in 1952 receiving his BCE degree during which time he was also engaged in land surveying. Following this he did postgraduate study at Virginia Polytechnic Institute obtaining his MS in 1954. He joined Naval Ship Research and Development Center in 1953 as a Junior Engineer and is currently the Head of the Engineering & Facilities Division Structures Department. His field of specialization is Structural Research and Development. Franklin I. Siegrist was born in Knoxville
Tenn. in 1937 receiving his earlier education in the Public Schools of Erie Pa. He attended Pennsylvania State University graduating in 1962 with a Bachelor of Science degree in Electrical Engineering having prior to that time served four years in the U. S. Navy. He was a Junior Engineer in the AC Spark Plug Division of General Motors from 1962 until 1964 at which time he came to the David Taylor Model Basin as an Electrical Engineer in the Industrial Department. He is currently Supervisory Engineer for Electrical and Electronics Engineering Structures Department Naval Ship Research and Development Center. His field of specialization is Electrical Engineering Control Systems Data Collection Systems Computer Applications to Structural Research and Hydraulic System Design. In the last of these he holds Patent Rights on a “Hydraulic Supercharge and Cooling Circuit” granted in 1970.
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