摘要:

A recursive algorithm is developed for solving the algebraic equations comprising the solution of the optimal static output feedback control problem of linear weakly-coupled systems. The proposed algorithm is very efficient from the numerical point of view, since only low-order systems are involved in algebraic calculations and the required solution can easily be obtained up to an arbitrary order of accuracy, that is 0(ϵ2k), where ϵ is a small weak-coupling parameter. The real-world example demonstrates the effectiveness of the proposed reduced-order algorithm and its advantages over the global full-order algorithm.

ISSN:0020-7179    

DOI:10.1080/00207178908953342

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A simple algorithm is briefly described for the control of rapidly time-varying unknown systems and its performance is illustrated by several linear and non-linear examples, including plants with unstable input zeros. The algorithm uses local flow behaviour and exhibits ‘one-step-adaptive model reference-like’ performance. The algorithm requires no prior knowledge of the plant except that it is linear in the control. The performance of the algorithm depends on its ability to make local predictions of plant behaviour and consequently the order of the controller is determined by the local curvature of the desired trajectories, the natural curvature of the plant trajectories, and the controller sampling rate.

ISSN:0020-7179    

DOI:10.1080/00207178908953343

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In this paper, we consider enhancing the performance of a stabilizing causal controllerK0(possibly time-varying) for a causal nominal plantG(possibly time-varying), with controller augmentations including an adaptive stable subsystemQ. The objective is to search on-line in the class of stabilizing causal controllers for the nominal plant, characterized in terms ofQand state space descriptions ofG,K0. For the case of time-invariant plants, most of the algorithms and theory of the paper specialize to known results. One formulation of the coprime factorizations using state-space description of time-varying systems, and associated characterization of the class of all stabilizing causal controllers used in our work, specializes to known results when the stabilizing controller has a full order state estimate feedback state space description.

ISSN:0020-7179    

DOI:10.1080/00207178908953344

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The stability robustness of the characteristic polynomial with perturbed coefficients for linear time-invariant systems is studied. The Schur, strictly Hurwitz, andG-stability properties of perturbed polynomials are all considered with a unified approach. New upper bounds on the allowable coefficient perturbation of a polynomial, for keeping one of the stability properties, are obtained. The proposed upper bounds are directly formulated in terms of the polynomial coefficients and can be computed easily. We also provide a sufficient condition for the discrete stability of interval polynomials and an algorithm for testing theG-stability of polynomials with constant coefficients. Illustrative examples are given to show the applicability of our results, especially in determining measures of stability robustness for any Schur polynomial subject to coefficient perturbation.

ISSN:0020-7179    

DOI:10.1080/00207178908953345

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A method of indirect adaptive multi-channel signal tracking control is introduced. The method is applied to the tracking problem when the multivariate system has been properly stabilized. A merit of this method is that the non-minimum phase property of the system will no longer restrict the implementation of the algorithm as many existing methods do.

ISSN:0020-7179    

DOI:10.1080/00207178908953346

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Time-invariant discrete-time descriptor systems of the formExk + 1=Axk+Buk, whereEandAaren×nmatrices and E may be singular, are considered. The problem is to find a feedback lawuk=Kxkthat drives the descriptor fromx0to the origin in less thanntime steps.

ISSN:0020-7179    

DOI:10.1080/00207178908953347

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The new concepts of the decentralized output feedback cycle index, the geometric multiplicities of decentralized fixed modes (DFM), and the decentralized output feedback variable polynomial (DVP) of a decentralized control system (DCS) are introduced. Their computational methods and some properties are given. It is shown that the decentralized output feedback cycle index is equal to one when the DCS has no decentralized fixed modes (DFM), or equal to the maximum of the geometric multiplicities of DFM otherwise. Almost every decentralized output feedback law can be used to make the zeros of the DVP distinct. It is also shown that almost any decentralized output feedback law will make the zeros of the DVP disjoint from any given finite set of points on the complex plane. It is then shown that if a DCS has no DFM then it can be made both controllable and observable with respect to any non-trivial input and output by applying almost any decentralized output feedback law.

ISSN:0020-7179    

DOI:10.1080/00207178908953348

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The problem of pole assignment and asymptotic observer design for multi-input multi-output continuous descriptor (generalized state-space) systems is studied. The problem is solved by introducing a new canonical form for controllable descriptor systems. The internal stability of the descriptor variable feedback and observer configuration is also considered, i.e. the extension of the separation principle to descriptor systems is given.

ISSN:0020-7179    

DOI:10.1080/00207178908953349

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A design method for a robust controller including a new type of observer called the proportional integral observer (PI observer) is proposed. The new observer differs from the conventional one by an integration path which provides additional degrees of freedom. This freedom can be used to make the observer-based controller design less sensitive to parameter variation of the system. It is shown that some of the difficulties that may arise in the exclusive pursuit of a design for the conventional observer-based controller from the point of view of system robustness are resolved in a straightforward manner using the PI observer. A systematic robustness recovery procedure is described for the PI observer-based controller design which asymptotically achieves the same loop transfer functions as the full-state feedback control implementation. A design example is included and the effectiveness of our method is illustrated by simulation results.

ISSN:0020-7179    

DOI:10.1080/00207178908953350

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A new technique is presented for the robust design of linear feedback controllers, such that the system closed-loop poles stay inside a prescribed region in the complex plane, despite bounded plant parameter variations. The method is based on the definition of a robust measure for any given controller and on the search, by an iterative method, for the controller which maximizes that measure.

ISSN:0020-7179    

DOI:10.1080/00207178908953351

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor