Browsing by Author "Chang, SK"

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A practical design for a robust fault detection and isolation system
(1997-03-01)
Hwang, DS
;
Chang, SK
;
Hsu, PL
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Based on a development for the unknown input observer (UIO) design, this paper presents a straightforward method of designing a robust fault detection and isolation (FDI) system for uncertain systems with unknown inputs. By exploiting the properties of a nominal model structure, we form a basic sec of residuals which is independent of the unknown input but is dependent on the measurements. Then, with this basic residual set, we append a dynamic weighting matrix to the residuals to increase the design freedom for meeting the required detection and isolation performance. Additionally, a generalized residual generator scheme (GRGS) is proposed to synthesize the parity relations for the isolation of faulty sensors in an uncertain system. The proposed strategy is verified through simulation studies performed on the control of a vertical take-off and landing (VTOL) aircraft in the vertical plane.
Design of general structured observers for linear systems with unknown inputs
(1997-03-01)
Chang, SK
;
You, WT
;
Hsu, PL
;
生醫工程研究所
;
電控工程研究所
Using the framework of the general structured (GS) observer, we present a straightforward procedure for designing an unknown input observer (UIO) for a linear system subject to unknown inputs ol uncertain disturbances. The set of all GS observers insensitive to unknown inputs is derived in this paper. Moreover, an extension of the UIO, called the extended UIO, is developed to estimate both the system state and the unknown input simultaneously. We show the existence conditions of a stable UIO are the same as those of a stable left inverse system. III addition, well-conditioned designs for both the state and unknown input estimations ale also explored. Conditions of transmission zeros reveal that to achieve a stable UIO, the uncertain system should be minimum-phase. To overcome this restriction, we adopt a two-delay output stabilized method to design the stabilized UIO without implementing extra sensors. Experimental results for a DC servo motor system demonstrate the applicability of the proposed methodologies. Copyright (C) 1997 Published by Elsevier Science Ltd.
Design of general structured observers for linear systems with unknown inputs
(1997-03-01)
Chang, SK
;
You, WT
;
Hsu, PL
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Using the framework of the general structured (GS) observer, we present a straightforward procedure for designing an unknown input observer (UIO) for a linear system subject to unknown inputs ol uncertain disturbances. The set of all GS observers insensitive to unknown inputs is derived in this paper. Moreover, an extension of the UIO, called the extended UIO, is developed to estimate both the system state and the unknown input simultaneously. We show the existence conditions of a stable UIO are the same as those of a stable left inverse system. III addition, well-conditioned designs for both the state and unknown input estimations ale also explored. Conditions of transmission zeros reveal that to achieve a stable UIO, the uncertain system should be minimum-phase. To overcome this restriction, we adopt a two-delay output stabilized method to design the stabilized UIO without implementing extra sensors. Experimental results for a DC servo motor system demonstrate the applicability of the proposed methodologies. Copyright (C) 1997 Published by Elsevier Science Ltd.
Robust fault detection and isolation with unstructured uncertainty using eigenstructure assignment
(1998-01-01)
Shen, LC
;
Chang, SK
;
Hsu, PL
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A numerical implementation is presented for the eigenstructure assignment approach to the design of a robust fault detection and isolation observer, By formulating the problem of multiple fault isolation in an eigenstructure, we develop a parametric characterization of all allowable eigenspaces, which provides a diagnostic observer capable of multiple fault isolation. In addition, a well-conditioned design of the allowable eigenvectors is shown to reduce the effect of the sus;em unstructured uncertainty. The resulting diagnostic observer is robust to unstructured modeling errors without losing fault detection sensitivity. A procedure for the synthesis of a reduced order diagnostic observer is also presented to increase the computational efficiency of the proposed observer.