担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

<p>This note addresses the conversion problem of <i>a priori</i> designed unstructured controllers to <i>observer-structured controllers</i>. Observer-structured controllers have been proposed as a structural extension of Luenberger observer-based controllers to accommodate linear parametric plant systems with unspecified nominal state-space matrices, and the usefulness has been demonstrated in the literature. However, the conversion process in the literature uses only the mathematical models of the plant systems and the <i>a priori</i> designed unstructured controllers, which might degrade the plant state estimation performance of the converted observer-structured controllers due to the possibility of unexpected disturbances, unmodeled dynamics, etc. of the practical operating environment. Therefore, a conversion method which well reflects the practical operating environment has been desired. To this end, this note proposes a conversion method, which is based on the least square method, by using the data of the plant systems controlled by the <i>a priori</i> designed unstructured controllers under practical operating environment, and illustrates the effectiveness of our method.</p>

DOI： 10.5687/iscie.38.146

Kyutacar

CiNii Research

その他リンク： http://id.ndl.go.jp/bib/034203036

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In most cases, control systems are subject to uncertainties. Therefore, it is crucial to design robust controllers against such uncertainties. One representative approach for this purpose is gain-scheduled control. Gain-scheduled control is a powerful, robust control method that can be designed when uncertainties that are measurable online, known as scheduling parameters, exist. However, scheduling parameters are not always measurable online, so it is important to relax the condition of their availability. To address this, a method that estimates the scheduling parameter by a disturbance observer and the recursive least squares method was proposed. Nevertheless, a major drawback of the approach was that the estimate could converge to zero for some numerical examples. To overcome this drawback, this paper proposes a novel estimation method that combines a disturbance observer with an adaptive estimation mechanism. This paper also shows the effectiveness of the proposed method through a numerical example.

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105033999759&origin=inward

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

This paper proposes an H∞ controller design method which realizes a two-degree-of-freedom (2-DOF) control system with lower sensitivity characteristics in the low-frequency range. A control system with a disturbance observer is a 2-DOF control system that can achieve low sensitivity characteristics in the specific low-frequency range. However, the design of a controller with a disturbance observer structure is a non-convex optimization problem if it is considered as an observer gain design problem. In addition, it has not yet been revealed whether a 2-DOF control system with the low sensitivity characteristics of the disturbance observer can be achieved by the H∞ controller design. Therefore, this paper proposes a design method for H∞ controllers that achieves the low-sensitivity characteristics of a type 2 servo system while maintaining the type 1 servo characteristics without specifying the disturbance observer structure. Numerical examples demonstrate the effectiveness of the proposed method.

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85216421475&origin=inward

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

This note revisits extended Linear Matrix Inequality (LMI) formulation of performance analysis, which incorporates static multiplier, for parametrically multi-affine discrete-time Linear Time-Invariant Parameter-Dependent (LTIPD) and Linear Periodically Time-Varying (LPTV) systems using lifting technique. Almost the same analysis conditions for parametrically affine discrete-time LTIPD/LPTV systems as the ones shown in this note have already been proposed in the literature, we thus focus on the simple derivations of the conditions using only Elimination lemma. To this end, a variant of extended LMI formulation, whose dimensional sizes are slightly larger than the conventional formulation with additional auxiliary matrices, is proposed in this note. It is also shown that our derived variant directly leads to a parametrically multi-affine extended LMI formulation for our addressed problem.

DOI： 10.1016/j.ifacol.2023.10.074

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85184962103&origin=inward