| 1. |
- Glad, Torkel, 1947-, et al.
(författare)
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Robustness Guarantees for Linear Control Designs with an Estimated Nonlinear Model Error Model
- 2004
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Ingår i: International Journal of Robust and Nonlinear Control. - Linköping : John Wiley & Sons. - 1049-8923 .- 1099-1239. ; 14:11, s. 959-970
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Tidskriftsartikel (refereegranskat)abstract
- Much attention in robust identification and control has been focused on linear low order models approximating high order linear systems. We consider the more realistic situation with a linear model approximating a nonlinear system. We describe how a nonlinear model error model can be developed, that allows a complete linear design process that results in a closed loop system with performance robustness guarantees (in terms of gain from disturbance to output) against the nonlinear error. Clearly the design can be successful only if the linear model is a reasonably good approximation of the system. A particular aspect of the design process is to define a workable definition of 'practical stability' for robust control design, with possible non-linear model errors. We use affine norms for that purpose.
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| 2. |
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| 3. |
- Rantzer, Anders
(författare)
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Friction Analysis Based on Integral Quadratic Constraints
- 2001
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Ingår i: International Journal of Robust and Nonlinear Control. - : Wiley. - 1099-1239 .- 1049-8923. ; 11:7, s. 645-652
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Tidskriftsartikel (refereegranskat)abstract
- Passivity arguments have long been used in the analysis of systems with friction. This paper proves a new set of integral quadratic constraints, which reduces the conservatism of such methods. The result is used to derive a quantitative bound on the amount of integrator leakage that is needed to remove stiction-induced oscillations in a servo system. Finally, an incremental version of the circle criterion is used to study the existence of subharmonics due to friction in a system subject to externally forced oscillations.
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| 4. |
- Xiang, F. L., et al.
(författare)
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QFT control design for an approximately linearized pneumatic positioning system
- 2003
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Ingår i: International Journal of Robust and Nonlinear Control. - : Wiley. - 1049-8923 .- 1099-1239. ; 13:7, s. 675-688
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Tidskriftsartikel (refereegranskat)abstract
- A block-oriented approximate feedback linearization for control of a pneumatic cylinder positioning system is introduced and a rather detailed discussion is presented on the uncertain linearization residual characterization. It is shown that making use of the characterized gain-phase information of the linearized system leads to a more reasonable trade-off between performance and stability in the QFT control design and thus results in high control performance. Simulation and experimental results are shown.
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| 5. |
- Zhang, J., et al.
(författare)
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Zeno hybrid systems
- 2001
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Ingår i: International Journal of Robust and Nonlinear Control. - : Wiley. - 1049-8923 .- 1099-1239. ; 11:5, s. 435-451
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Panagopoulos, Hélène, et al.
(författare)
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PID control design and $H_infty$ loop shaping
- 2000
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Ingår i: International Journal of Robust and Nonlinear Control. - 1099-1239. ; 10:15, s. 1249-1261
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Tidskriftsartikel (refereegranskat)abstract
- This paper shows that traditional methods for design of PID controllers can be related to robust H= control. In particular, it shows how the specifications in terms of maximum sensitivity and maximum complementary sensitivity are related to the weighted H= norm introduced by Glover and McFarlane [5]. The paper also shows how to use the Vinnicombe metric to classify those classes of systems which can be stabilized by the presented design methods in Åström et al [3] and Panagopoulos et al [4].
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| 7. |
- Lefeber, E., et al.
(författare)
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Linear Controllers for Exponential Tracking of Systems in Chained Form
- 2000
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Ingår i: International Journal of Robust and Nonlinear Control. - 1099-1239. ; 10:4, s. 243-264
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we address the tracking problem for a class of non-holonomic chained-form control systems. We present a simple solution for both the state feedback and the dynamic output feedback problem. The proposed controllers are linear and render the tracking error dynamics globally ?-exponentially stable. We also deal with both control problems under input saturation. Application of the results to the control of wheeled mobile robots is illustrated by means of simulations of a car pulling a single trailer.
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| 8. |
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