摘要:

AbstractThe optimization problem of adaptive stochastic terminal control systems accommodating to changing disturbance characteristics is considered. It is assumed that a plant with randomly changing or fixed structure is operated under non‐Gaussian disturbances described by non‐linear models. Direct information about random structural changes of the disturbance model is absent. For systems with various types of structural changes the optimal adaptive terminal control laws are obtained in analytical form. Filtering‐prediction‐recognition algorithms are designed for realization of these control laws. It is found that the synthesized regulators provide a disturbance accommodation control strategy with adaptation to structural changes of the disturbance model. A principal difference from traditional control laws is illustrated by simulation

ISSN:0890-6327    

DOI:10.1002/acs.4480080201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractIn this paper, in the case when there are no modelling errors, bursting phenomena in extended‐least‐squares‐ (ELS‐) based self‐tuning control are analysed. It is shown that in the absence of external excitation and without imposing structural conditions on the system model, bursts of the tracking error and consequently drift of the parameter estimates are possible. By analysing the possible occurrence of bursting, an upper bound on the convergence rate of the tracking error is established. It is demonstrated that it is the self‐excitation mechanism which provides global stability of the adaptive system. In other words, the possible instability of the adaptive loop generates a bounded condition number of the covariance matrix. This in turn implies stabilization of the adaptive system. In this paper we also discuss a stochastic gradient algorithm with a convergence rate similar to that presently established for the ELS‐based self‐tu

ISSN:0890-6327    

DOI:10.1002/acs.4480080202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractIn this paper the local robust stability of model reference adaptive control for time‐varying plants with unmodelled dynamics under the persistent excitation condition is studied. It is shown that for arbitrary initial conditions of the adaptive system all signals in the adaptive loop are bounded if the command input is persistently exciting and the plant parameter variation and the magnitude of the unmodelled component are sufficiently small in the mea

ISSN:0890-6327    

DOI:10.1002/acs.4480080203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractIn this paper we address the problem of improving the asymptotic performance guarantees of a class of model reference adaptive controllers under insufficient excitation and in the presence of perturbations such as non‐parametric uncertainty and bounded disturbances. We show that for a class of perturbations whose normalized effect is bounded by ana prioriknown function of time an estimate of the parametric uncertainty set can be obtained on‐line via a set membership estimator. Furthermore, by incorporating this estimate as an additional constraint in the adaptive law generating the controller parameters, we show that the resulting adaptive controller offers dead‐zone‐like performance guarantees in the lim‐sup sense while preserving the desirable root‐mean‐square performance guarantees of gradient‐b

ISSN:0890-6327    

DOI:10.1002/acs.4480080204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThis paper introduces a novel high‐order Yule‐Walker (HOYW) method for estimating sinusoidal frequencies. the proposed method does not require singular value decomposition (SVD) of the data covariance matrix, has a computational complexity similar to the overdetermined Yule‐Walker (OYW) method and a statistical accuracy close to that of the SVD‐based HOYW method, and is easy to implement in recursive form since it involves only linear operations on the data. an example of the performance that can be achieved by an adaptive form of this new HOWY method in a time‐varying scenario is a

ISSN:0890-6327    

DOI:10.1002/acs.4480080205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY