摘要:

This paper deals with closed-loop eigenstructure assignment by output-feedback control in linear multivariable systems for the general case of multiple eigenvalues. The approach is algebraic in nature and operates directly on the closed-loop characteristic equation using fundamental properties of determinants and their derivatives. A compact form for the controller gain matrix is derived and expressed in terms of a set of parameter vectors that specify the non-uniqueness of the solution of the eigenvalue-assignment problem. Some of these parameter vectors assume restricted forms while others are free. A computational scheme is given in which the free parameter vectors are determined in such a way as to assign the corresponding eigenvectors and generalized eigenvectors in a weighted least-square-error sense. An illustrative numerical example is included.

ISSN:0020-7179    

DOI:10.1080/00207178808906266

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

We present an inverse scattering interpretation of the classical minimal partial realization problem posed in a slightly generalized context. Our approach starts by considering a canonical cascade-form structure for the realization of arbitrary transfer functions, where the cascade structure can be interpreted as the description of a layered wave scattering medium. In this context the partial realization problem calls for a recursive process of layer identification from a given input-response pair (the scattering data). The realization algorithm uses a causality principle to progressively determine the parameters of cascaded linear 2-ports that model the successive wave-interaction layers. This method for approaching the realization problem turns out to fit nicely into a framework that was also used to obtain fast, structured linear estimation algorithms and cascade realizations for digital filters.

ISSN:0020-7179    

DOI:10.1080/00207178808906267

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The problem of transforming non-linear systems with input disturbances to their linear equivalents is investigated. A characterization of the class of non-linear systems with disturbances that are equivalent to controllable quasi-linear systems with disturbances, ż = Az + bv + ξ(z) d, is given. The necessary transformations (state-space coordinate changes and control input-space coordinate changes by non-linear feedforward and feedback) are presented and their implications for control system synthesis are discussed. Finally a numerical example is given,

ISSN:0020-7179    

DOI:10.1080/00207178808906268

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A new method, called the intrinsic method, is proposed in this paper to derive suitable Lyapunov functions for a general class of non-linear systems expressed in state variables as n first-order non-linear differential equations. This method, which applies the integration-by-parts procedure, derives a Lyapunov function directly from the differential equations under study.

ISSN:0020-7179    

DOI:10.1080/00207178808906269

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The purpose of this paper is to present a new design algorithm for discrete-time MIMO systems given as strictly properz-domain transfer matrices. The algorithm combines some well-known results, partly adapting them for application to discrete-time systems. Basically, it consists of the following steps: (a) represent the system as a coprime right matrix fraction description G(z) = N(z)D−1(z), where D(z) is column reduced; (b) optimally (in some sense to be specified) choose a closed-loop denominator polynomial matrix DC1(z); and (c) compute a controller following the method by Wolovich (1973) such that the closed-loop transfer matrix is T(z) = N(z)Dc1−1(z)F for some constant matrixF.

ISSN:0020-7179    

DOI:10.1080/00207178808906270

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

After a brief survey of the relations between time-and frequency-domain representations of the observer-based linear state feedback loop, the parameterization of the compensator is discussed. It is shown that the free parameters specified by the state feedback matrix K and the output error feedback matrix L in the time domain appear as coefficients in the polynomial matrices [Dtilde](s) and(s), characterizing the closed-loop dynamics in the frequency domain. These polynomial matrices can either be chosen arbitrarily (pole-placement problem) or they may be derived as solutions from the corresponding optimal control or the optimal estimation problems, respectively. Starting from the polynomial matrices [Dtilde](s) and(s), the doubly coprime fractional representations of the system and of the compensator transfer matrices can be computed directly without recurrence to the time domain results. From these representations, the right and left coprime compensator matrix fraction descriptions can easily be evaluated using standard algorithms.

ISSN:0020-7179    

DOI:10.1080/00207178808906271

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

On-line identification of the parameters in a non-linear output-affine model is considered. The recursive maximum likelihood estimator, which was originally derived for linear systems, is extended to work for non-linear systems which can be described by a stochastic form of Sontag's output-affine model. Some numerical implementation aspects are discussed, a brief convergence analysis is given and a computer simulation study is included.

ISSN:0020-7179    

DOI:10.1080/00207178808906272

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Results for time-invariant linear systems concerning controllability, reachability, output controllability, stabilizability, and target path controllability are extended to time-varying systems. For the extensions which are already known in the literature elementary proofs are given. Moreover, necessary and sufficient conditions are given for the (strong) admissibility of a target path.

ISSN:0020-7179    

DOI:10.1080/00207178808906273

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The problem of minimizing the L∞-norm of some stable rational matrix E(s) subject to two basic types of matrix interpolation constraints is considered: given anti-stable rational matrices N¯(s) and M¯(s), the interpolating matrix £(s) is required to satisfy either the condition N¯(s)E(s) = M¯(s) or the condition that N¯(s)E(s) has an unstable projection equal to M¯(s). These two kinds of constraints are directly related to model-matching problems arising from H∞optimal control. Specific conditions on N¯(s) and M¯(s) for the interpolation problems to be well-posed are discussed and closed-form characterizations for both optimal and suboptimal solutions in E(s) are provided. The analysis is based on a state-space setting and the results are suitable for computational purposes.

ISSN:0020-7179    

DOI:10.1080/00207178808906274

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This paper deals with the problem of decentralized stabilization for a class of unknown large-scale dynamic systems formed of interconnected subsystems under constant disturbances. A decentralized adaptive control scheme is proposed based on the Lyapunov direct method and a condition of asymptotic stability is derived. Then the decentralized adaptive control scheme is applied for a class of robot manipulators to track the desired trajectory as closely as possible despite a wide range of manipulator motions and parameter uncertainties of links and payload.

ISSN:0020-7179    

DOI:10.1080/00207178808906275

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor