ISSN:0020-7179    

DOI:10.1080/00207179208934260

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Multi-layered perceptrons with the back-propagation learning algorithm represent an emerging tool in non-linear systems modelling and control. One of the main drawbacks of the traditional back-propagation algorithm is its slow rate of convergence. A new method to improve the speed of the learning phase, involving the use of a suitable number of additional neural networks, is proposed. The auxiliary networks work concurrently to the principal network without slowing down the procedure. In this paper, it is shown how to choose the structure of the auxiliary networks and how these have to be trained. Several examples confirm the suitability of the proposed procedure

ISSN:0020-7179    

DOI:10.1080/00207179208934261

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In this paper we consider robustness measures (stability radii) for system matrices which are subjected to structured real and complex perturbations of the form A↦A + BDC where B, C are given matrices. Our object is twofold:

ISSN:0020-7179    

DOI:10.1080/00207179208934262

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Owing to current concern over the environment, there is much interest in renewable sources of electrical power generation of which one of the most promising is wind power. However, it is not yet a mature technology and many basic issues have yet to be resolved. One such issue is the best means of regulating the wind turbines. Many horizontal axis grid-connected wind turbines have the capability to vary the angle of pitch of the blades which can be exploited to provide regulation. The purpose of this paper is to report on an extensive investigation into the control of active pitch regulation of constant speed, grid-connected horizontal axis wind turbines. The performance attainable by PI control design and classical Nyquist-Bode loop shaping is determined and compared

ISSN:0020-7179    

DOI:10.1080/00207179208934263

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This paper is concerned with the frequency response properties of MIMO generalized predictive control. A number of frequency response indicators (characteristic loci, principal gains and Gershgorin bands) are used to evaluate stability and the performance of the closed-loop. This is done via three realistic examples which demonstrate the effect of the predictive controllertuning parameterson the measures of robust stability and performance in the frequency domain. A series ofheuristic tuning rulesis compiled for methodical tuning of this type of controller in multivariable environments

ISSN:0020-7179    

DOI:10.1080/00207179208934264

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An almost disturbance decoupling technique guaranteeing internal stability of a linear system while using either state feedback or only measurement feedback is considered. Under a set of necessary and sufficient conditions, a state feedback controller is explicitly constructed. Similarly, a full or reduced order observer-based measurement feedback controller is explicitly constructed under a set of necessary and sufficient conditions. All the developed controllers guarantee the asymptotic stability of the closed-loop system in the absence of disturbances. Furthermore, they can reduceH∞norm of the transfer function from the external disturbance to the controlled output to any arbitrarily specified value. Unlike other methods which merely give the solvability conditions, our method explictly constructs them. Also our controllers are parametrized in terms of tuning parameters, by the tuning of which the disturbance reflected in the output can be attenuated to any desired degree of accuracy

ISSN:0020-7179    

DOI:10.1080/00207179208934265

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This paper analyses and extends an easily implemented direct model reference adaptive control procedure. The paper focuses on the major limitation of this control approach which is the satisfaction of a stringent strictly positive real sufficiency condition in order to guarantee asymptotic tracking. Attempts, to date, to address this problem have been unable to relax simultaneously the stringent condition and maintain asymptotic tracking capabilities. This paper presents three different modifications to existing versions of this algorithm which substantially relax the stringent sufficiency condition while providing asymptotic tracking. These three modifications achieve this goal by imposing slight adjustments to existing sufficiency conditions. A simulation example demonstrates that the modifications eliminate the steady state error inherent in the existing methods

ISSN:0020-7179    

DOI:10.1080/00207179208934266

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This paper sets out a revised view of the classical diagonal dominance method for multivariable feedback systems. The various types of dominance measure are unified by using onefundamental dominancetheorem (FD)l. It is shown that the fundamental dominance condition yields the smallest dominance measure when compared with all the known classical diagonal dominance measures. In addition it is shown that the dominance measures such as row/column, generalized dominance and a few new ones are special cases and can be derived from this same FD theorem. This improved dominance criterion also provides the sufficient condition for a system to be approximated by a nominal one in the sense that the stabilization of this nominal system will assure the stability of the original one. Finally, a new type of dominance measure named L-dominance is presented. It has been shown that this new approach yields an even smaller dominance measure, and that when it is applied to matrices with non-positive off-diagonal elements, the L-dominant condition and the M-matrix condition are equivalent, but the testing of the former is easier and can be achieved via simple Gaussian eliminations

ISSN:0020-7179    

DOI:10.1080/00207179208934267

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An optimal Routh approximant of a single-input single-output dynamic system is a reduced-order transfer function of which the denominator is obtained by the Routh approximation method while the numerator is determined by minimizing a time-response integral-squared-error (ISE) criterion. In this paper, a new elegant approach is presented for obtaining the optimal Routh approximants for linear time-invariant continuous-time systems. The approach is based on the Routh canonical expansion, which is a finite-term orthogonal series of rational basis functions, and minimization of the ISE criterion. A procedure for combining the above approach with the bilinear transformation is also presented in order to obtain the optimal bilinear Routh approximants of linear time-invariant discrete-time systems. The proposed technique is simple in formulation and is amenable to practical implementation

ISSN:0020-7179    

DOI:10.1080/00207179208934268

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The paper considers the proposition of standard bench-mark plant models, performance indices and testing procedures for stochastic adaptive control. Only single input-single output linear plants are considered. A set of stochastically disturbed plant models is chosen, and the proposed measures of control algorithm performance (regulability and control cost) are evaluated and discussed for the bench-mark plant models set. A set of standard modes for evaluating the performance indices for the chosen plant models completes the proposed benchmark test

ISSN:0020-7179    

DOI:10.1080/00207179208934269

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor