1. |
|
|
2. |
|
|
3. |
|
|
4. |
-
Master's Theses in Automatic Control 1984-1985
- 1985
-
Reports (other academic/artistic)abstract
- The report contains abstracts of Master theses (examensarbeten) made at the Department of Automatic Control, Lund, during the academic year 84/85. During this year 16 theses were made by 18 students. Most of the theses are written in Swedish with an English abstract.
|
|
5. |
|
|
6. |
-
Reglermöte -85
- 1985
-
Editorial proceedings (peer-reviewed)abstract
- The workshop Reglermöte 85 was arranged during May 29-30 1985 at the Department of Automatic Control at Lund Institute of Technology. About 100 persons participated evenly divided between industry and universities. 18 papers were presented. Abstracts of the papers are given in the report.
|
|
7. |
|
|
8. |
|
|
9. |
|
|
10. |
- Wittenmark, Björn, et al.
(author)
-
Adaptive Decoupling of Multivariable Systems
- 1987
-
In: International Journal of Control. - : Informa UK Limited. - 0020-7179 .- 1366-5820. ; 46:6, s. 1992-2009
-
Journal article (peer-reviewed)abstract
- For many industrial processes, it is of interest to design a decoupling precompensator. The precompensator makes it possible to design controllers based on single-input-single-output models of the process. A model of the process must be known to design the precompensator. This paper shows how the precompensator can be designed adaptively using input-output measurements. The precompensator is first designed for the case when the process is known. The adaptive precompensator is then constructed using the certainty equivalence principle. The convergence properties and the implementation of the adaptive decoupler are discussed. It is shown that the adaptive scheme will converge provided the system is persistently excited and that a suitable model structure is used in the estimation.
|
|
11. |
- Wittenmark, Björn
(author)
-
Adaptive Stability Augmentation
- 1988
-
In: IFAC Proceedings Volumes : 8th IFAC/IFOORS Symposium on Identification and System Parameter Estimation 1988 - 8th IFAC/IFOORS Symposium on Identification and System Parameter Estimation 1988. ; 21:9
-
Conference paper (peer-reviewed)abstract
- Most adaptive controllers do not assume any a priori knowledge about the process to be cont rolled. In most situations there is, however, some knowledge about the process. This knowledge should be used to improve the performance compared to the “black box” approach of earlier adaptive controllersThe a priori knowledge is in this paper used in the estimation of the process and also in the design of the controller. The use in the design is new compared to earlier approaches. The a priori knowledge is here used to design a nominal controller. The unmodelled part of the process is estimated and an adaptive stability augmentation signal is added to the nominal controller. Different types of a priori knowledge and design methods are discussed and the performances are investigated through analysis
|
|
12. |
|
|
13. |
|
|
14. |
|
|
15. |
- Wittenmark, Björn, et al.
(author)
-
An Adaptive Pole Placement Controller Based on Pole-Zero Parameterization
- 1988
-
In: IFAC Proceedings Volumes : 8th IFAC/IFOORS Symposium on Identification and System Parameter Estimation 1988 - 8th IFAC/IFOORS Symposium on Identification and System Parameter Estimation 1988. ; 21:9
-
Conference paper (peer-reviewed)abstract
- The pule placement design principle pruvides a good way of determining a closed loop system with desired properties. The method has been used in adaptive contexts for many years. A drawback of the method is, however, that the polynomial formulation mav lead to robustness problems because of the sensitivity with respect to the coefficients of the polynomials. Further, unless all process zeros are cancelled a set of linear equations has to be solved at each step in time. In this paper an attempt is made to avoid these two problems. The sensitivity of the polynomial formulation is avoided by parameterizing the model in the poles and zeros, which are estimated on-line. With the plant expressed in this form it is possible to parameterize the controller such that the solution of the Diophantine equation corresponds to the solution of a triangular system of equations. The controller parameters can thus be computed recursively without extensive computations
|
|
16. |
|
|
17. |
- Wittenmark, Björn, et al.
(author)
-
Constrained Pole Placement Using Transformation and LQ-design
- 1987
-
In: Automatica. - : Elsevier BV. - 0005-1098. ; 23:6, s. 767-769
-
Journal article (peer-reviewed)abstract
- A new procedure for constrained pole-placement is presented. The poles of the closed loop system are placed within a circle in the left half plane. The design procedure is noniterative and the solution is obtained via linear quadratic (LQ) design for a transformed system. The circle can be chosen in order to obtain good transient properties of the closed loop system. The method combines the properties of pole-placement and LQ-design.
|
|
18. |
- Wittenmark, Björn
(author)
-
Datatekniklinjen vid LTH
- 1985
-
In: Ordo. - 0345-8970. ; 19:4, s. 5-6
-
Journal article (pop. science, debate, etc.)
|
|
19. |
|
|
20. |
|
|
21. |
- Wittenmark, Björn, et al.
(author)
-
Identification based on data with sampling delays
- 1988
-
In: Automatica. - : Elsevier BV. - 0005-1098. ; 24:2, s. 271-273
-
Journal article (peer-reviewed)abstract
- Most identification and design methods for discrete time data assume that the inputs and outputs are sampled at the same time instants. In practice, there is always a delay due to the conversion times in the analog to digital converters. In the paper it is shown how data with sampling delays can be used to obtain the model corresponding to synchronous sampling. The modification is simple and can be done after the estimation. It is only required that a suitable structure is used for the estimated model and that the delay is known.
|
|
22. |
- Wittenmark, Björn
(author)
-
Implementation and Application of Adaptive Control
- 1988
-
In: IFAC Proceedings Volumes : 2nd International IFAC Symposium on Adaptive Control of Chemical Processes 1988 (ADCHEM '88) - 2nd International IFAC Symposium on Adaptive Control of Chemical Processes 1988 (ADCHEM '88). ; 21:7
-
Conference paper (peer-reviewed)abstract
- There are many things to consider when implementing an adaptive controller. The paper contains a discussion of some of these issues. When an adaptive controller is going to to work in an industrial environment it is of outmost importance that the designer has thought of all situations and combination of conditions that may occure. Special attention is given to the interaction between the controller and the estimator. Some types of applications are discussed to point out when adaptive control can be a good alternative to a fixed gain controller.
|
|
23. |
|
|
24. |
- Wittenmark, Björn
(author)
-
Integrators, Nonlinearities and Antireset Windup for Different Control Structures
- 1989
-
In: IEEE Xplore : 1989 American Control Conference - 1989 American Control Conference.
-
Conference paper (peer-reviewed)abstract
- In most control schemes it is advantageous to introduce integrators to eliminate off-set due to load disturbances. It is, however, also important to introduce nonlinearities, for instance due to limitations in actuators. The interaction between the integrator and the nonlinearities will cause problems with reset windup. Ways to handle anti-reset windup for different controller configurations are discussed in the paper. Simple PID-controllers, cascade loops, state feedback controllers and pole-placement controllers are given a unified treatment. The discussion is supplemented with simulations.
|
|
25. |
|
|
26. |
- Wittenmark, Björn
(author)
-
Sampling of a system with a time delay
- 1985
-
In: IEEE Transactions on Automatic Control. - 0018-9286. ; 30:5, s. 507-510
-
Journal article (peer-reviewed)abstract
- This note deals with the problem of sampling a continuous-time system which contains a time delay. It is shown that the infinite-dimensional continuons-time system can be represented by a finite-dimensional sampled data system. It is shown that there are simple expressions for the sampled data state-space representations.
|
|
27. |
- Wittenmark, Björn, et al.
(author)
-
Self-Tuning Control
- 1987
-
In: Systems and Control Encyclopedia.
-
Book chapter (peer-reviewed)
|
|
28. |
|
|
29. |
|
|
30. |
|
|
31. |
- Wittenmark, Björn
(author)
-
Travel Report from Australia and China
- 1987
-
Reports (other academic/artistic)abstract
- The report gives a summary of Björn Wittenmark's visits to China and Australia during the academic year1986 /87 . An overview of the research is given together with a summary of impressions during visits at differentuniversities.
|
|
32. |
|
|
33. |
|
|
34. |
|
|