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Uncertainty in Sampled Systems

Rohrs, Charles, E.; Stein, Gunter and Åström, Karl Johan LU (1985) American Control Conference, 1985
Abstract
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... (More)
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 (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to conference
publication status
published
subject
keywords
Adaptive algorithm, Adaptive control, Adaptive systems, Filters, Frequency response, Programmable control, Sampled data systems, Sampling methods, Stability Uncertainty
conference name
American Control Conference, 1985
external identifiers
  • Scopus:0022223147
language
English
LU publication?
yes
id
9edad72b-2949-45b0-b7c3-765b234b882f (old id 8517871)
date added to LUP
2016-02-03 15:53:25
date last changed
2016-10-13 04:56:47
@misc{9edad72b-2949-45b0-b7c3-765b234b882f,
  abstract     = {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},
  author       = {Rohrs, Charles, E. and Stein, Gunter and Åström, Karl Johan},
  keyword      = {Adaptive algorithm,Adaptive control,Adaptive systems,Filters,Frequency response,Programmable control,Sampled data systems,Sampling methods,Stability Uncertainty},
  language     = {eng},
  title        = {Uncertainty in Sampled Systems},
  year         = {1985},
}