Closed loop identification using a modified Hansen scheme: Paper

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It is often not feasible or even impossible to identify a plant in open loop. This might be because the plant contains unstable poles, or it is simply too expensive to remove the plant from its intended operation, among other possibilities. There are several methods for identifying a plant in closed loop [4], and one such method is the Hansen scheme [1]. Standard identification using Hansen scheme demands generating the identification signals indirectly. In this paper it is instead proposed to use the relationship between the Youla factorization of a plant and its stabilizing controller to directly measure the signals used for identification. A simulation example and identification of a gas bearing is given to show the method in action. Rotors supported by controllable gas bearings are open loop stable systems. However as the rotational speed is increased feedback control is necessary in order to keep the system stable. Furthermore because the dynamics of such a system depends on the rotational speed it is needed to conduct an identification while the system is part of a closed loop scheme. The authors believe the paper able to contribute towards a simpler and more direct way of identifying closed loop plants using Hansen scheme.
Original languageEnglish
Article number012009
Book seriesJournal of Physics: Conference Series
Number of pages13
Publication statusPublished - 2015
Event12th European Workshop on Advanced Control and Diagnosis - Pilsen, Czech Republic
Duration: 19 Nov 201520 Nov 2015


Conference12th European Workshop on Advanced Control and Diagnosis
Country/TerritoryCzech Republic


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