摘要:

A recursive identification algorithm for multivariable systems is developed by extending the SISO augmented UD identification (AUDI) algorithm developed by Niu, Fisher and Xiao in 1992. This least-squares type algorithm has a simple, compact structure and provides simultaneous identification of model structure and parameters, with excellent numerical properties. A multivariable input/output difference equation model is used as the model representation for identification, and it is shown how the corresponding (unique) canonical state-space representation can also be generated by a straightforward transformation. The algorithm is easier to interpret and more straightforward to implement than the corresponding RLS approaches.

ISSN:0020-7179    

DOI:10.1080/00207179408923123

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper is devoted to the study of robust strict positive real stabilization of SISO uncertain systems, i.e. finding a single controller that not only robustly stabilizes a plant with uncertainties under unity-feedback but also makes the closed-loop system robustly strictly positive real. It is proved that there must exist a stable controller achieving robust strict positive real stabilization of uncertain systems with both parameter variations and unstructured uncertainties under some reasonable assumptions. The propemess of the controller is guaranteed when the largest relative degree of an uncertain system is retricted. By applying these results to nonlinear systems, some significant conclusions on asymptotic hyperstability robustness are given.

ISSN:0020-7179    

DOI:10.1080/00207179408923124

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Given a continuous time transfer function g(s), this paper provides closed-form solutions for the coefficients of discrete time transfer functions gz) Similar solutions are also provided for g(s), given g(z). Three integration methods are used for each direction (termed forward and inverse, respectively) of transformation: (a) the 'forward rectangular rule’; (6) the 'backward rectangular rule’; and (c) Tustin's method (the 'trapezoidal rule’). Thus, the normally cumbersome method of substitution for s by a rational approximation for esδ, where δ is the sampling interval, followed by algebraic sorting of thezor s-domain polynomials, is completely circumvented by the methods described. Examples are given to show the simplicity and efficacy of the methods.

ISSN:0020-7179    

DOI:10.1080/00207179408923125

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The use of Laurent power series expansions of the eigenvector matrix of a linear multivariable transfer function matrix G(z) holds the key to the physical realization of commutative controllers. In general, however, such controllers would be anti-causal. It is the purpose of this paper to show that there are enough degrees of freedom in the choice of the controller eigenfunctions both to effect gain/phase compensation of the frequency response of the eigenfunctions of G(z), and to force the resulting control law to be causal. The results of the paper are shown to be superior to those possible through the use of approximate commutative controllers proposed earlier.

ISSN:0020-7179    

DOI:10.1080/00207179408923126

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The robustness properties of controllers, which are optimally robust with respect to normalized coprime factor uncertainty, are analysed. It is shown that such optimally robust controllers admit perturbations which are, in size, larger than the robustness measure. It is shown how such perturbations can be constructed by solving Hankel norm approximation problems.

ISSN:0020-7179    

DOI:10.1080/00207179408923127

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A framework is proposed for the development and analysis of robust observers for uncertain dynamical systems. A variable structure systems approach is used. Emphasis is placed upon the numerical tractability of the associated synthesis procedure. A selected numerical example is used to illustrate the proposed algorithm.

ISSN:0020-7179    

DOI:10.1080/00207179408923128

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An identification method is presented for estimating the parameters of a discrete-time linear dynamic system excited by non-gaussian input signals using the fourth-order cumulants of the input and output signals, both of which are contaminated by additive gaussian noise. Two types of estimators of the fourth-order cumulants of the input and output signals are proposed for this method. The first is conventional. The second, which is new allows us only to have a recursive algorithm for computing the parameter estimators. The parameter estimators obtained by this algorithm are shown to be strongly consistent under certain weak conditions. Simulation examples are included to demonstrate the effectiveness of the proposed method.

ISSN:0020-7179    

DOI:10.1080/00207179408923129

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper deals with the control of regularly c-perturbed nonlinear systems. On the basis of a 'nominal’ control law (i.e. designed with respect to the unperturbed plant), an iterative procedure is proposed for achieving, at a fixed order of approximation, the requirements specified oh the dynamics of the feedback control system. The sufficient conditions ensuring the applicability of the procedure, are verified when dealing with feedback linearization problems. Some working examples developed in the paper, illustrate the efficiency of such a design strategy.

ISSN:0020-7179    

DOI:10.1080/00207179408923130

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

In this paper, we study the almost sure-stability and δmoment stability of discrete-time jump linear systems with a finite state form process. Criteria for almost sure and δ-moment stability, which are necessary and sufficient conditions for (scalar) one-dimensional systems, are derived. The relationship between almost sure and 6-moment stability for (scalar) one-dimensional systems is also presented. If the system matrices commute, necessary and sufficient conditions for almost sure stability are obtained.

ISSN:0020-7179    

DOI:10.1080/00207179408923131

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper presents an approach for designing a robust tracking controller for a two degree of freedom series mass-spring-damper system. Our approach uses the newly developed technique of model reference robust control for SISO systems first described by Qu and Dawson (1992) and more recently by Qu et al. (1992), and we specifically show how this technique can be applied to a common benchmark problem (Wie and Bernstein 1990) for robust control design. This problem is the development of a control that can force the last degree of freedom (i.e. end point) of a mass-spring-damper system to follow a desired trajectory. For this problem we show how a robust controller can achieve global uniform ultimate boundedness (GUUB) for the position tracking error of the system's last degree of freedom in spite of unknown model parameters and additive bounded disturbances.

ISSN:0020-7179    

DOI:10.1080/00207179408923132

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor