1. |
- 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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2. |
- Bauer, Dietmar
(författare)
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Order Estimation for Subspace Methods
- 2001
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Ingår i: Automatica. - : Elsevier. - 0005-1098 .- 1873-2836. ; 37:10, s. 1561-1573
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Tidskriftsartikel (refereegranskat)abstract
- Three different order estimation criteria in the context of subspace algorithms are introduced and sufficient conditions for strong consistency are derived. A simulation study points to open questions.
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3. |
- Bauer, Dietmar, et al.
(författare)
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Some Facts about the Choice of the Weighting Matrices in Larimore Type of Subspace Algorithms
- 2002
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Ingår i: Automatica. - : Elsevier. - 0005-1098 .- 1873-2836. ; 38:5, s. 763-773
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Tidskriftsartikel (refereegranskat)abstract
- In this paper the effect of some weighting matrices on the asymptotic variance of the estimates of linear discrete time state space systems estimated using subspace methods is investigated. The analysis deals with systems with white or without observed inputs and refers to the Larimore type of subspace procedures. The main result expresses the asymptotic variance of the system matrix estimates in canonical form as a function of some of the user choices, clarifying the question on how to choose them optimally. It is shown, that the CCA weighting scheme leads to optimal accuracy. The expressions for the asymptotic variance can be implemented more efficiently as compared to the ones previously published.
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4. |
- Forssell, Urban, et al.
(författare)
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Some Results on Optimal Experiment Design
- 2000
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Ingår i: Automatica. - : Elsevier. - 0005-1098 .- 1873-2836. ; 36:5, s. 749-756
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Tidskriftsartikel (refereegranskat)abstract
- The problem of designing the identification experiments to make them maximally informative with respect to the intended model use is studied. The focus is on how to identify models that are good for control, so called `Identification for Control'. A main result is that we derive explicit expressions for the optimal controller and the optimal reference signal spectrum to use in the identification experiment for the case that only the misfit in the dynamics model is penalized and when a linear combination of the input and output variances is constrained.
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5. |
- Frisk, Erik, et al.
(författare)
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A minimal polynomial basis solution to residual generation for fault diagnosis in linear systems
- 2001
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Ingår i: Automatica. - 0005-1098 .- 1873-2836. ; 37:9, s. 1417-1424
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Tidskriftsartikel (refereegranskat)abstract
- A fundamental part of a fault diagnosis system is the residual generator. Here a new method, the minimal polynomial basis approach, for design of residual generators for linear systems, is presented. The residual generation problem is transformed into a problem of finding polynomial bases for null-spaces of polynomial matrices. This is a standard problem in established linear systems theory, which means that numerically efficient computational tools are generally available. It is shown that the minimal polynomial basis approach can find all possible residual generators and explicitly those of minimal order. © 2001 Elsevier Science Ltd. All rights reserved.
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6. |
- Gevers, Michel, et al.
(författare)
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Asymptotic Variance Expressions for Closed-Loop Identification
- 2001
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Ingår i: Automatica. - 0005-1098 .- 1873-2836. ; 37:5, s. 781-786
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Tidskriftsartikel (refereegranskat)abstract
- Asymptotic variance expressions are analyzed for models that are identified on the basis of closed-loop data. The considered methods comprise the classical `direct' method, as well as the more recently developed indirect methods, employing coprime factorized models, dual Youla/Kucera parametrizations and the two-stage approach. The variance expressions are compared with the open-loop situation, and evaluated in terms of their relevance for subsequent model-based control design.
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7. |
- Gevers, Michel, et al.
(författare)
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Optimal Experimental Designs with Respect to the Intended Model Application
- 1986
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Ingår i: Automatica. - : Elsevier. - 0005-1098 .- 1873-2836. ; 22:5, s. 543-554
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the design of identification experiments is to make the collected data maximally informative with respect to the intended use of the model, subject to constraints that might be at hand. When the true system is replaced by an estimated model, there results a performance degradation that is due to the error in the transfer function estimates. Using some recent asymptotic expressions for the bias and the variance of the estimated transfer function, it is shown how this performance degradation can be minimized by a proper experiment design. Several applications, where it is beneficial to let the experiment be carried out in closed loop, are highlighted.
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8. |
- Ghandhari, Mehrdad, et al.
(författare)
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A control strategy for controllable series capacitor in electric power systems
- 2001
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Ingår i: Automatica. - 0005-1098 .- 1873-2836. ; 37:10, s. 1575-1583
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Tidskriftsartikel (refereegranskat)abstract
- It has been verified that a controllable series capacitor with a suitable control scheme can improve transient stability and help to damp electromechanical oscillations. A question of great importance is the selection of the input signals and a control strategy for this device in order to damp power oscillations in an effective and robust manner. Based on Lyapunov theory a control strategy for damping of electromechanical power oscillations in a multi-machine power system is derived. Lyapunov theory deals with dynamical systems without inputs. For this reason, it has traditionally been applied only to closed-loop control systems, that is, systems for which the input has been eliminated through the substitution of a predetermined feedback control. However, in this paper, we use Lyapunov function candidates in feedback design itself by making the Lyapunov derivative negative when choosing the control. This control strategy is called control Lyapunov function for systems with control inputs. Also, two input signals for this control strategy are used. The first one is based on local information and the second one on remote information derived by the single machine equivalent method.
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9. |
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10. |
- Glad, Torkel, 1947-, et al.
(författare)
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Bounds on the Response Time under Control Constraints
- 2001
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Ingår i: Automatica. - : Elsevier. - 0005-1098 .- 1873-2836. ; 37:12, s. 2073-2076
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Tidskriftsartikel (refereegranskat)abstract
- We consider the problem of transferring the output of a linear system from one equilibrium value to another under control amplitude constraint. It is possible to give a simple lower bound on the time required, expressed in the longest time constant, the gain of the system, the change in y and the control bound. This theoretical bound appears to be useful as a practical lower bound of the rise time.
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