摘要:

AbstractA non‐linear adaptive filter is introduced and applied to the classical problem of estimating time‐varying‐parameter linear regression models with unknown error variances and a time‐varying transition matrix. The filter is basically a new result in what is known as Sridhar filtering theory. In deriving the filter, which we call the ‘Pontryagin filter’, the Pontryagin minimum principle and the method of invariant imbedding were used. The properties (bias and consistency) of the estimates of the time‐varying parameters are the

ISSN:0890-6327    

DOI:10.1002/acs.4480040502

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

年代:1990

数据来源: WILEY

摘要:

AbstractTwo indirect adaptive linearizing controllers are proposed, in continuous time, for the class of non‐linear systems which are linearly parametrized and which can be linearized by state feedback through a parametrized diffeomorphism. In each case the stability of the closed loop is analysed in detail. It is also shown how these control laws can be extended to related situations, i.e. input‐output feedback linearization and non‐linear parametriza

ISSN:0890-6327    

DOI:10.1002/acs.4480040503

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe results of an earlier paper concerning global robustness of single‐loop self‐tuning controllers are extended to include multiple self‐tuning controllers operating in a multiple‐interacting‐loop environment. The robust stability is shown to depend on the singular value loci of a certain transfer function matrix. The need for control weighting to ensure global robust stability is e

ISSN:0890-6327    

DOI:10.1002/acs.4480040504

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

年代:1990

数据来源: WILEY

摘要:

AbstractA system with purely deterministic disturbances can be represented by a non‐minimal model. In this paper we establish conditions on the input to the system so that when the RLS algorithm is applied to identify its parameters, convergence is guaranteed. It should be pointed out that no boundedness conditions on this input are require

ISSN:0890-6327    

DOI:10.1002/acs.4480040505

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

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper proposes extended least‐squares (ELS) for ARMAX model identification of continuous‐time and certain discrete‐time systems. The schemes have a relaxed strictly positive real (SPR) condition for global convergence. The relaxed SPR scheme is achieved by introducing overparametrization and prefiltering but without introducing ill‐conditioning. The schemes presented are the first such proposed for continuous‐time systems.The concepts developed in continuous time carry through to fast‐sampled continuous‐time systems and associated discrete‐time ELS algorithms. For such situations, in comparison with previously proposed discrete‐time schemes, the degree of overparametrization required in the proposed scheme of this paper is significantly lower. The reduction is achieved by using more suitable prefiltering and overparametrization techniques than previously proposed.We also establish the persistence of excitation (PE) of the regression vectors in the proposed ELS schemes to assure strong consistency, obtain convergence rates and provide robustness to unmodelled dynamics. To prove the PE of continuous‐time regression vectors, we develop output reachability characterization for MIMO linear cont

ISSN:0890-6327    

DOI:10.1002/acs.4480040506

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn this paper some results of direct decentralized adaptive control based on input/output methods are presented. The plant is assumed to have several local adaptive controllers, each of which can observe only local system outputs and control only local inputs. Conditions for the stability of the decentralized control scheme are derived using an extended I/O sector stability theorem of Safonov.20The associated error model of the adaptive scheme can be represented in the form of an equivalent feedback configuration comprising a non‐linear time‐varying feedforward block describing the adaptation law and a linear time‐invariant feedback block which depends on the interactions of the different control loops. Stability is obtained if the blocks verify certain sector conditions. It will be demonstrated that conventional adaptation algorithms have to be modified. The proposed RLS parameter adaptation law differs from standard algorithms by the introduction of signal normalization, interlaced parameter adaptation and a variable forgetting factor.The allowable class of interactions is restricted by the sector condition for the linear feedback block. It will be shown that less conservative conditions can be found when a parallel filter, the so‐called correction network, is introduced. Such filters make direct adaptive control possible even for non‐minimum phase systems. In addition, the correction network makes the adaptive controller robust to uncertainties in the structure of

ISSN:0890-6327    

DOI:10.1002/acs.4480040507

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

年代:1990

数据来源: WILEY

ISSN:0890-6327    

DOI:10.1002/acs.4480040508

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

年代:1990

数据来源: WILEY

ISSN:0890-6327    

DOI:10.1002/acs.4480040501

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

年代:1990

数据来源: WILEY