Abstract
In observer-based control integral or controller windup can systematically be prevented by the observer technique, i.e., by feeding the saturated plant input signal into the observer. This prevents all windup effects caused by the dynamics of the compensator. The possibly remaining windup effects are then the same as if constant state feedback control had been applied. When using the classic approach for robust rejection of persistent disturbances the state-plus-disturbance observer is subdivided into the state observer and the controlled signal model. Thus the observer technique is only applicable when taking additional measures or when resorting to a recently published dual design method. Here, a very simple design for MIMO PI compensators is suggested which directly yields the basis for the observer technique.
Zusammenfassung
Bei beobachterbasierten Reglern liefert die Beobachtertechnik, nämlich eine Rückführung des begrenzten Stellsignals in den Beobachter, eine systematische Vermeidung des von Stellbegrenzungen ausgelösten Regler oder Integral-Windup. Sie beseitigt alle unerwünschten Auswirkungen der Regler-Dynamik auf das nichtlineare Verhalten des Kreises. Die danach noch auftretenden Windup-Effekte sind dieselben, als wenn lediglich eine Rückführung gemessener Zustandsgrössen vorläge. Beim klassischen Ansatz zur robusten Unterdrückung konstanter Störungen ist der Zustands-plus-Störbeobachter aufgeteilt in den Zustandsbeobachter und das geregelte Störmodell. Deshalb ist eine Anwendung der Beobachtertechnik nur möglich, wenn man zusätzliche Massnahmen ergreift oder einen neulich publizierten dualen Ansatz verwendet. Hier wird ein sehr einfaches Vorgehen zum Entwurf von Mehrgrössen PI-Reglern vorgestellt, das die Basis für die Beobachtertechnik direkt liefert.
About the author
Peter Hippe worked as Akademischer Direktor at Lehrstuhl für Regelungstechnik of the Universität Erlangen-Nürnberg till September 2006. Main fields of interest: Control systems with plant input restrictions, design of state controllers and of MIMO compensators in the frequency domain.
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Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
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Research funding: None declared.
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Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
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