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| 2. |
- Hagander, Per, et al.
(författare)
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A Self-Tuning Filter for Fixed-Lag Smoothing
- 1976
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Konferensbidrag (refereegranskat)abstract
- The problem of estimating a discrete-time stochastic signal which is corrupted by additive white measurement noise is discussed. How the stationary solution to the fixed-lag smoothing problem can be obtained is shown. The first step is to construct an innovation model for the process. It is then shown how the fixed-lag smoother can be determined from the polynomials in the transfer function of the innovation model. In many applications, the signal model and the characteristics of the noise process are unknown. It is shown that it is possible to derive an algorithm which on-line finds the optimal fixed-lag smoother, a self-tuning smoother. The self-tuning smoother consists of two parts: an on-line estimation of the parameters in the one-step ahead predictor of the measured signal, and a computation of the smoother coefficients by simple manipulation of the predictor parameters. The smoother has good transient, as well as good asymptotic, properties.
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| 3. |
- Hagander, Per, et al.
(författare)
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A Self-Tuning Filter for Fixed-Lag Smoothing
- 1977
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Ingår i: IEEE Transactions on Information Theory. - 0018-9448. ; 23:3, s. 377-384
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Tidskriftsartikel (refereegranskat)abstract
- The problem of estimating a discrete-time stochastic signal which is corrupted by additive white measurement noise is discussed. How the stationary solution to the fixed-lag smoothing problem can be obtained is shown. The first step is to construct an innovation model for the process. It is then shown how the fixed-lag smoother can be determined from the polynomials in the transfer function of the innovation model. In many applications, the signal model and the characteristics of the noise process are unknown. It is shown that it is possible to derive an algorithm which on-line finds the optimal fixed-lag smoother, a self-tuning smoother. The self-tuning smoother consists of two parts: an on-line estimation of the parameters in the one-step ahead predictor of the measured signal, and a computation of the smoother coefficients by simple manipulation of the predictor parameters. The smoother has good transient, as well as good asymptotic, properties.
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| 4. |
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| 5. |
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| 6. |
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| 7. |
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| 8. |
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| 9. |
- Ljung, Lennart, 1946-, et al.
(författare)
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On a Stabilizing Property of Adaptive Regulators
- 1976
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Ingår i: Proceedings of the 4th IFAC Symposium on Identification and System Parameter Estimation. - 9780444851130 ; , s. 380-388
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Konferensbidrag (refereegranskat)
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| 10. |
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| 11. |
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| 12. |
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| 13. |
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Master's Theses in Automatic Control 1977-1978
- 1979
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report contains abstracts of master thesis (examensarbete) made at the Department of Automatic Control, Lund, during the academic year 77/78. During this year 16 theses were made by 23 students. The theses are written in Swedish with an English abstract.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Wittenmark, Björn
(författare)
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A two-level estimator for time varying parameters
- 1979
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Ingår i: Automatica. - 0005-1098. ; 15:1, s. 85-89
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Tidskriftsartikel (refereegranskat)abstract
- A crucial part in an adaptive control system is the estimation of the unknown parameters of the process. The estimation is often done using a Kalman filter or an Extended Kalman filter. These estimators give good results if the parameters are not varying too fast. When the parameters are varying fast there are difficulties for the estimator to follow the variations. This paper outlines a new approach to the estimation problem. The new estimator consists of two parts. One conventional Kalman filter for fine estimation and one estimator for coarse estimation. The coarse estimator consists of a finite number of fixed a priori models and a decision mechanism which points out the model which best fits the data. The paper describes the two-level estimator and discusses its properties. Some numerical examples illustrate the behavior of the estimator.
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| 18. |
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| 19. |
- Wittenmark, Björn, et al.
(författare)
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Comments on 'Single step versus multistep performance criteria for steady state SISO systems'
- 1979
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Ingår i: IEEE Transactions on Automatic Control. - 0018-9286. ; 24:1, s. 140-141
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Tidskriftsartikel (refereegranskat)abstract
- It is well-known that there exists a critical control weighting parameter which results in an unstable controller design if the uncontrolled system is unstable or nonminimum phase and a single stage cost functional is used. The purpose of this note is to show that the determination of this parameter reduces to solving a root-locus problem.
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| 20. |
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| 21. |
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| 22. |
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| 23. |
- Wittenmark, Björn
(författare)
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Stochastic Adaptive Control Methods: A Survey
- 1975
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Ingår i: International Journal of Control. - : Informa UK Limited. - 0020-7179 .- 1366-5820. ; 21, s. 705-730
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Tidskriftsartikel (refereegranskat)abstract
- There is a vast literature about adaptive (self-organizing, self-optimizing) control systems. The aim of this paper is to point out some of the main ideas. Since there exists good survey papers about several of the classes of adaptive controllers the main part of this paper will concentrate on recent developments. The paper will cover stochastic adaptive controllers. The problem of dual control is given particular attention.
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| 24. |
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| 25. |
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| 26. |
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| 27. |
- Åström, Karl Johan, et al.
(författare)
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Theory and applications of adaptive regulators based on recursive parameter estimation
- 1975
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Ingår i: IFAC Proceedings Volumes : 6th IFAC World Congress (IFAC 1975) - 6th IFAC World Congress (IFAC 1975). ; 8:1:1
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Konferensbidrag (refereegranskat)abstract
- The motivation for this work has been to simplify the design of regulators for industrial processes. The regulators designed can be regarded as self-tuning regulators. They will serve as a substitute for the time-consuming process of plant experiments, parameter estimation and control design. The regulators can also be used as adaptive regulators for processes with slowly varying parameters. The paper describes such regulators, outlines their theory and reviews industrial applications.
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| 28. |
- Åström, Karl Johan, et al.
(författare)
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Theory and Applications of Self Tuning Regulators
- 1977
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Ingår i: Automatica. - : Elsevier. - 0005-1098 .- 1873-2836. ; 13:5, s. 457-476
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Tidskriftsartikel (refereegranskat)abstract
- This paper reviews work on self-tuning regulators. The regulator algorithms, their theory and industrial applications are reviewed. The paper is expository—the major ideas are covered but detailed analysis is given elsewhere.
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