| 1. |
- Bernhardsson, Bo, et al.
(författare)
-
A Stabilizing Switching Scheme for Multi Controller Systems
- 1996
-
Ingår i: IFAC Proceedings Volumes. ; 29, s. 2627-2632
-
Konferensbidrag (refereegranskat)abstract
- The stability of a multi-controller system is analyzed using Lyapunov theory. Stability is guaranteed by a switching strategy determined by a combination of separate Lyapunov functions for the different controllers. The behavior on sliding surfaces is analyzed using non-smooth analysis according to Filippov. Two examples illustrate the theory.
|
|
| 2. |
|
|
| 3. |
- Hast, Martin, et al.
(författare)
-
PID Design by Convex-Concave Optimization
- 2013
-
Ingår i: Proceedings 2013 European Control Conference (ECC). ; , s. 4460-4465
-
Konferensbidrag (refereegranskat)abstract
- This paper describes how PID controllers can be designed by optimizing performance subject to robustness constraints. The optimization problem is solved using convex-concave programming. The method admits general process descriptions in terms of frequency response data and it can cope with many different constraints. Examples are presented and some pitfalls in optimization are discussed.
|
|
| 4. |
|
|
| 5. |
- Åström, Karl Johan, et al.
(författare)
-
Comparison of Riemann and Lebesque sampling for first order stochastic systems
- 2002
-
Ingår i: Proceedings of the 41st IEEE Conference on Decision and Control, 2002. - 0191-2216. ; 2, s. 2011-2016
-
Konferensbidrag (refereegranskat)abstract
- The normal approach to digital control is to sample periodically in time. Using an analog of integration theory we can call this Riemann sampling. Lebesgue sampling or event based sampling is an alternative to Riemann sampling. It means that signals are sampled only when measurements pass certain limits. In this paper it is shown that Lebesgue sampling gives better performance for some simple systems.
|
|
| 6. |
- Åström, Karl Johan, et al.
(författare)
-
Systems with Lebesgue sampling
- 2003
-
Ingår i: Directions in Mathematical Systems Theory and Optimization (Lecture Notes in Control and Information Sciences). - 0170-8643. ; 286, s. 1-13
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Sampling is normally done periodically in time. For linear time invariant systems this leads to closed loop systems that linear and periodic. Many properties can be investigated by considering the behavior of the systems at times that are synchronized with the sampling instants. This leads to drastic simplifications because the systems can be described by difference equations with constant coefficients. This is the standard approach used today when designing digital controllers. Using an analog from integration theory, periodic sampling can also be called Riemann sampling. Lebesgue sampling or event based sampling, is an alternative to Riemann sampling, it means that signals are sampled only when measurements pass certain limits. This type of sampling is natural when using many digital sensors such as encoders. Systems with Lebesgue sampling are much harder to analyze than systems with Riemann sampling, because the time varying nature of the closed loop system can not be avoided. In this paper we investigate some systems with Lebesgue sampling: Analysis of simple systems shows that Lebesgue sampling gives better performance than Riemann sampling.
|
|
