• Journal of Institute of Control, Robotics and Systems
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• v.1 no.2
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• pp.71-77
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• 1995

The control effectiveness and disturbance suppressibility are mainly governed by a left eigenstructure of a system. In this paper, a control algorithm which uses an output feedback eigenstructure assignment scheme is proposed in order that a desired closed-loop system has the specified degree of controllability and/or degree of disturbance suppressibility. To do this, a modal and a gross disturbance suppressibility measures are proposed. A modified version of Hamdan and Nayfeh's modal controllability measure is also presented. The validity and usefulness of the proposed measures and the controller design algorithm are illustrated by designing a controller for a third-order system as an example.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.412-419
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• 1993

The transient responses of a linear system having undesired disturbances are dominantly governed by the system's left eigenstructure(eigenvalues/left eigenvectors). In control system design problem of altering the transient response of the system, both the controllability and the disturbance suppressibility, should be considered simultaneously to obtain a robust, effective controller. The controllability of the system may be degraded if the left eigenstructure is chosen to suppress the disturbance, or vice versa. In this paper, first, proposed are a modal disturbance suppressibility measure and an improved version of the modal controllability measure suggested by Hamdan and Nayfeh. Second, a simple and general left eigenstructure assignment scheme, considering both the proposed modal disturbance suppressibility measure and the improved version of modal controllability measure, is suggested. When the previous works are applied to assign the left eigenvectors may differ from the desired ones. But the proposed left eigenstructure assignment scheme makes it possible to achieve the desired colsed-loop eigenvalues exactly, provided the desired left eigenvectors reside in the achievable subspace. In case the desired left eigenvectors do not reside in the achievable subspace, the closed-loop eigenvalues are achieved exactly and the left eigenvectors are assigned to the best possible set of eigenvectors in the least square sense. Finally, a numerical example is included to confirm and demonstrate the usefulness of our propositions and to illustrate the proposed design scheme.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.618-621
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• 1995

In this paper, in order to obtain a disturbance decouplable as well as effective and disturbance suppressible controller, a simultaneous assignment methodology of the left and right eigenstructure is proposed. The biorthogonality property between the left and right model matrices of a system as well as the relations between the achievable right model matrix and states selsction matrices are used to develop the methodology. the proposed concurrent eigenstructure assignment methodologh guarantees that the desired eigenvalues are achieved exactly and the desired left and right eigenvectors are assigned to the best possible(achievable) sets of eigenvectors in the least square sense, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.230-235
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• 1996

Eigenstructure (eigenvalues/eigenvectors) assignment has been shown to be a useful tool for flight control system design. In the sense of the eigenstructure assignment, the effectiveness and disturbance suppressibility of a controller depend mainly on the left eigenstructure (eigenvalues/left eigenvectors) of a system. On the other hand, the disturbance decouplability is governed by the right eigenstructure (eigenvalues/right eigenvectors) of the system. In this paper, in order to obtain a disturbance decouplable as well as effective and disturbance suppressible controller, a concurrent assignment methodology of the left and right eigenstructures is proposed. The biorthogonality condition between the left and right modal matrices of a system as well as the relations between the achievable right modal matrix and state selection matrices are used to develop the methodology. The proposed concurrent eigenstructure assignment methodology guarantees that the desired eigenvalues are achieved exactly and the desired left and right eigenvectors are assigned to the best possible(achievable) sets of eigenvectors in the least square sense, respectively. The proposed design methodology is applied to designing a lateral flight control system for an L-1011 aircraft with disturbances.

• Journal of Institute of Control, Robotics and Systems
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• v.1 no.1
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• pp.4-12
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• 1995

In the sense of eigenstructure (eigenvalues/eignenvectors) assignment, the effectiveness and disturbance suppressibility of a controller depend mainly on the left eigenstructure (eignevalues/left eigenvectors) of a system. On the other hand, the disturbance decouplability is governed by the right eigenstructure (eignevalues/right eigenvectors) of the system. In this paper, in order to obtain a disturbance decouplable as well as effetive and disturbance suppressible controller, a concurrent assignment methodology of the left and right eigenstructure is proposed. The biorthogonality condition between the left and right modal matrix and state selection matrices are used to develop the methodology. The proposed concurrent eigenstructure assignment methodology guarantees that the desired eigenvalues are achieved exactly and the desired left and right eigenvectors are assigned to the best possible (achievable) sets of eigenvectors in the least square sense, respectively. A numerical example is presented to illustrate the validity and usefulness of the proposed methodology.