Closed loop identification using a modified Hansen scheme

Sekunda, André Krabdrup; Niemann, Hans Henrik; Poulsen, Niels Kjølstad; Santos, Ilmar

doi:10.1088/1742-6596/659/1/012009

Cited by 4 publications

(6 citation statements)

References 4 publications

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“…There are several ways to prove the relationship between the 2 set of signals { α , β } and { η , ε }, with one approach to be found in our other work . Whereas, it is not possible to directly excite the system using η , it is using the signal α .…”

Section: Preliminary Resultsmentioning

confidence: 99%

Detector design for active fault diagnosis in closed‐loop systems

Sekunda

Niemann

Poulsen

2018

Adaptive Control & Signal

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Fault diagnosis of closed-loop systems is extremely relevant for high-precision equipment and safety critical systems. Fault diagnosis is usually divided into 2 schemes: active and passive fault diagnosis. Recent studies have highlighted some advantages of active fault diagnosis based on dual Youla-Jabr-Bongiorno-Kucera parameters. In this paper, a method for closed-loop active fault diagnosis based on statistical detectors is given using dual Youla-Jabr-Bongiorno-Kucera parameters. The goal of this paper is 2-fold.First, the authors introduce a method for measuring a residual signal subject to white noise. Second, an optimal detector design is presented for single and multiple faults using the amplitude and phase shift of the residual signal to conduct diagnosis. Here, both the optimal case of a perfect model and the suboptimal case of a model with uncertainties are discussed. The method is successfully tested on a simulated system with parametric faults.

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Section: Preliminary Resultsmentioning

confidence: 99%

Detector design for active fault diagnosis in closed‐loop systems

Sekunda

Niemann

Poulsen

2018

Adaptive Control & Signal

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“…7 ), through its project P & P control developed a novel concept for process distributed control, which allows the control system to self reconfigure once an instrumental change is introduced Stoustrup (2009b) . In 2015, a new dual YK based identification scheme is proposed in order to avoid the use of indirect excitation signals in the reference and feedforward inputs modifying the one proposed in 2003 Sekunda et al (2015) by the Technical University of Denmark, and in 2018 they showed experimental results on using the proposed scheme. In 2019, experimental results are shown using YK based MMAC in ITS systems Navas, Milans, Flores, and Nashashibi (2020) .…”

Section: Discussionmentioning

confidence: 99%

“…Closed-loop identification of a piezoelectrically controlled gas bearing using the modified version of the original Hansen scheme in Sekunda et al (2015) was presented in Sekunda, Niemann, Poulsen, and Santos (2018) . It highlights the need of closed-loop identification since the system is unstable without feedback control.…”

Section: Applicationsmentioning

confidence: 99%

Advances in Youla-Kucera parametrization: A Review

Mahtout

Navas

Milanés

et al. 2020

Annual Reviews in Control

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Youla-Kucera (YK) parametrization was formulated decades ago for obtaining the set of controllers stabilizing a linear plant. This fundamental result of control theory has been used to develop theoretical tools solving many control problems ranging from stable controller switching, closed-loop identification, robust control, disturbance rejection, adaptive control to fault tolerant control. This paper collects the recent work and classifies them according to the use of YK parametrization, Dual YK parametrization or both, providing the latest advances with main applications in different control fields. A final discussion gives some insights on the future trends in the field.

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“…It was argued in Sekunda et al 12 that the signals should be obtained directly from the controller by modifying it to the form, shown in Figure 3.…”

Section: Identification Using the Modified Hansen Schemementioning

confidence: 99%

“…This identification procedure is known as the Hansen scheme and was first introduced in Hansen et al 11 The original version of the Hansen scheme used external excitation signals to indirectly excite the Youla deviation system. A modified version of the Hansen scheme, first introduced in Sekunda et al, 12 is used instead in this article, which makes it possible to directly impose an excitation signal onto the Youla deviation system. A gas bearing easily becomes an unstable system when the rotational speed is increased.…”

Section: Introductionmentioning

confidence: 99%

Closed loop identification of a piezoelectrically controlled radial gas bearing: Theory and experiment

Sekunda

Niemann

Poulsen

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part I:

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Gas bearing systems have extremely small damping properties. Feedback control is thus employed to increase the damping of gas bearings. Such a feedback loop correlates the input with the measurement noise which in turn makes the assumptions for direct identification invalid. The originality of this paper lies in the investigation of the impact of using different identification methods to identify a rotor-bearing systems dynamic model when a feedback loop is active. Two different identification methods are employed. The first method is open loop Prediction Error Method (PEM) while the other method is the modified Hansen scheme. Identification based on the modified Hansen scheme is conducted by identifying the Youla deviation system using subspace identification. Identification of the Youla deviation system is based on the Youla-Jabr-Bongiorno-Kucera parametrisation of plant and controller. By using the modified Hansen scheme, identification based on standard subspace identification methods can be used to identify the Youla deviation system of the gas bearing. This procedure ensures the input to the Youla deviation system and the noise are uncorrelated even though the system is subject to feedback control. The effect of identifying the Youla deviation system compared to direct subspace identification of the gas bearing is further investigated through a simulation example. Experiments are conducted on the piezoelectrically-controlled radial gas bearing. A dynamic model is identified using the modified Hansen scheme as well as using PEM identification. The resulting models are compared for different imperfect nominal models, to examine under which conditions each method should be used.

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Closed loop identification using a modified Hansen scheme

Cited by 4 publications

References 4 publications

Detector design for active fault diagnosis in closed‐loop systems

Detector design for active fault diagnosis in closed‐loop systems

Advances in Youla-Kucera parametrization: A Review

Closed loop identification of a piezoelectrically controlled radial gas bearing: Theory and experiment

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