The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

Hiroyuki Ichikawa - One of the best experts on this subject based on the ideXlab platform.

  • Robust pole assignment for vibration control of flexible structures
    Journal of Intelligent Material Systems and Structures, 2001
    Co-Authors: Hiroshi Okubo, Hiroyuki Ichikawa
    Abstract:

    This paper proposes a method of structure/controller design by robust pole assignment for active vibration suppression of flexible structures. The proposed method assigns the closed-loop poles at the specified point in the complex plane and quasi-minimizes the condition number of the closed-loop Modal Matrix via structure/controller design. Reducing the condition number improves stability robustness and control performance of the designed closed-loop system. This paper also introduces a new index of condition number for the cost function. Use of this index in place of an actual condition number reduces computational effort and improves problem solvability significantly. Feasibility of the proposed method is demonstrated with numerical examples.

  • Structure and controller design for vibration control of flexible structures via robust pole assignment
    Proceedings of the 1998 IEEE International Conference on Control Applications (Cat. No.98CH36104), 1
    Co-Authors: Hiroshi Okubo, Hiroyuki Ichikawa, T. Nishimura
    Abstract:

    This paper presents a new approach to the integrated design of structure and controller for vibration control of flexible structures. The proposed method assigns closed-loop poles at specified locations in the complex plane and minimizes the condition number of the closed-loop Modal Matrix via structure/controller design, i.e., quasi-simultaneous design of structural parameters, actuator locations, and feedback gains. Minimizing the condition number provides the system robust stability in the sense that it suppresses deviations of the closed-loop eigenvalues caused by system uncertainties. The result of the structure/controller design for an experimental model of active structure shows that the proposed method is highly useful for improving the system robustness and control performance.

Hiroshi Okubo - One of the best experts on this subject based on the ideXlab platform.

  • Robust pole assignment for vibration control of flexible structures
    Journal of Intelligent Material Systems and Structures, 2001
    Co-Authors: Hiroshi Okubo, Hiroyuki Ichikawa
    Abstract:

    This paper proposes a method of structure/controller design by robust pole assignment for active vibration suppression of flexible structures. The proposed method assigns the closed-loop poles at the specified point in the complex plane and quasi-minimizes the condition number of the closed-loop Modal Matrix via structure/controller design. Reducing the condition number improves stability robustness and control performance of the designed closed-loop system. This paper also introduces a new index of condition number for the cost function. Use of this index in place of an actual condition number reduces computational effort and improves problem solvability significantly. Feasibility of the proposed method is demonstrated with numerical examples.

  • Structure and controller design for vibration control of flexible structures via robust pole assignment
    Proceedings of the 1998 IEEE International Conference on Control Applications (Cat. No.98CH36104), 1
    Co-Authors: Hiroshi Okubo, Hiroyuki Ichikawa, T. Nishimura
    Abstract:

    This paper presents a new approach to the integrated design of structure and controller for vibration control of flexible structures. The proposed method assigns closed-loop poles at specified locations in the complex plane and minimizes the condition number of the closed-loop Modal Matrix via structure/controller design, i.e., quasi-simultaneous design of structural parameters, actuator locations, and feedback gains. Minimizing the condition number provides the system robust stability in the sense that it suppresses deviations of the closed-loop eigenvalues caused by system uncertainties. The result of the structure/controller design for an experimental model of active structure shows that the proposed method is highly useful for improving the system robustness and control performance.

Youngjin Park - One of the best experts on this subject based on the ideXlab platform.

  • Order reduction based on singular values of a Modal Matrix
    Mechanical Systems and Signal Processing, 1994
    Co-Authors: Youngjin Park
    Abstract:

    Abstract We propose a systematic method to select the master dofs, which are retained in the reduced model after the order reduction process. The proposed method is based on the fact that the Modal Matrix of any full model is orthogonal while that of the reduced order model is, in general, skewed. We propose as far as possible, to keep the orthogonality of the Modal Matrix during the reduction process. To quantify the skewness of the reduced Modal Matrix, we define the Singularity Factor (SF) and Absolute Singularity Factor (ASF) based on the singular values of the Matrix. It is shown that a set of master dofs with the minimum SF has the minimum estimation error. We can use ASF to evaluate the estimation performance of a specific master dof compared to the best case when the full dofs are measured. Illustrative examples show that master dofs chosen based on SF (or ASF) agree very well with the ones chosen by the expert.

Gun-myung Lee - One of the best experts on this subject based on the ideXlab platform.

  • Prediction of strain responses from the measurements of displacement responses
    Mechanical Systems and Signal Processing, 2007
    Co-Authors: Gun-myung Lee
    Abstract:

    A method to predict the strain responses from the measurements of displacement responses is considered. The method uses a transformation Matrix which is composed of a displacement Modal Matrix and a strain Modal Matrix. The method can predict strains at points where displacements are not measured as well as at displacement measuring points. One of the drawbacks of the strain prediction method is that the displacement responses must be measured at many points on a structure simultaneously. This difficulty can be overcome by measuring the FRFs between displacements at a reference point and other point in sequence with a two channel measuring equipment. This procedure is based on the assumption that the characteristics of excitation applied to the structure do not vary with time.

B. Labibi - One of the best experts on this subject based on the ideXlab platform.

  • Application of Matrix perturbation theory in robust control of large-scale systems
    Automatica, 2012
    Co-Authors: Alireza Esna Ashari, B. Labibi
    Abstract:

    The aim of this paper is to develop new results for robust centralized and decentralized control of large-scale systems using Matrix perturbation theory. A new robustness measure is proposed which is more appropriate for large-scale systems than the existing measures. The use of this new index allows for an evaluation of system eigenvalue sensitivity to perturbations without calculating the eigenvectors and the condition number of the Modal Matrix. In addition, a novel robust decentralized controller design method is proposed to assign the closed-loop eigenvalues of the large-scale system in a desired region. This method is based on eigenstructure assignment of isolated subsystems. The assignment of overall closed-loop poles in the desired region is guaranteed provided that certain sufficient conditions for the isolated subsystems are satisfied. Simulation results are given to show the efficiency of the new methods.