摘要:

In this paper we consider optimal control problems for infinite-dimensional systems governed by non-linear evolution equations. We show that the set of trajectories of such systems is compact in a space of continuous functions, and then using this fact we solve Lagrange and time optimal control problems. Then we concentrate on linear systems and we prove a new ‘bang-bang’ principle and a corresponding maximum principle. We conclude with an example of a control system governed by a non-linear parabolic partial differential equation.

ISSN:0020-7179    

DOI:10.1080/00207178908559727

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effects of sampled-data control on continuous-time linear stochastic systems are considered. Plants including an arbitrary control delay are treated. A predictor corresponding to this delay is introduced, and it is shown how design and analysis can be performed on a system without delayed control actions. A comparison of control performance for some typical digital control strategies is made, and the effect of different sampling periods is examined. The continuous-time average output variance is adopted as a measure of the closed-loop behaviour.

ISSN:0020-7179    

DOI:10.1080/00207178908559728

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In a practical variable structure system (VSS), owing to the time delay of the switching device, the sliding motion of the system can no longer be ideal. This affects the insensitivity property of the VSS. We propose a method called the equal excursion sliding regime (EESR) to overcome this problem. Using EESR we may obtain an almost ideal sliding regime. Examples are presented to illustrate the advantages of the proposed method.

ISSN:0020-7179    

DOI:10.1080/00207178908559729

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A simple and rigorous approach that determines the generic rank of a structural matrix is presented. This approach is based upon an integer linear programming (ILP) formulation which features the property of total unimodularity in the set of constraints. The integer linear programming formulation of the proposed approach with the addition of integer cuts can be used to identify all the structurally redundant equations and/or excess columns of a system. This approach can also be used as a systematic tool to search for all the possible (not necessarily feasible) sets of controlled and manipulated variables of large-scale control systems. The features of the proposed algorithm are illustrated through a representative set of example problems.

ISSN:0020-7179    

DOI:10.1080/00207178908559730

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The paper deals with constrained controllability of linear discrete-time systems with multiple delays on controls and states. Necessary and sufficient conditions for local reachability and null-controllability of linear discrete-time delay systems with constrained controls in infinite-dimensional spaces are given.

ISSN:0020-7179    

DOI:10.1080/00207178908559731

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A complete proof is given of global convergence to zero of the prediction error and asymptotic optimality for a direct adaptive controller is established based on multistep quadratic cost minimization with a receding horizon philosophy. The only substantial assumptions are that the controller designed when the parameters are known, stabilizes the plant and the exact knowledge of the firstNy(Ny-optimization horizon) impulse response coefficients of the plant. The technical hurdles for the development of a comprehensive convergence theory of this type of controller are also highlighted.

ISSN:0020-7179    

DOI:10.1080/00207178908559732

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The fact that the smoothing error is a (wide sense) Markov process is somehow surprising since smoothed estimates depend upon both past and future data. In this paper we first give a simple and general proof of this fact. Then we use the so-called complementary models introduced by Weinert and Desai to derive forwards and backwards markovian models for the smoothing error in state-space models. By exploring the structure of the complementary models we show that, under certain restrictions, only two simple structured models exist, one that runs forwards in time and the other that runs backwards in time. The forwards complementary model leads to the forward Rauch-Tung-Striebel (RTS) smoothing formula and to a backwards markovian model for the error, whereas the backwards model leads to the backward RTS formula and to a forwards error model. The two models for the smoothing error can be derived one from the other by a forward-backward transformation that preserves the sample paths. Finally, by using a combination of the two complementary models we give yet another proof for the two-filter smoothing formula.

ISSN:0020-7179    

DOI:10.1080/00207178908559733

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

State-space formulae and proofs are given for ail the important steps in discrete-timeH8optimization. The steps closely follow the algorithms for continuous-time systems, but there are some technically involved differences in the detail that make their derivation non-trivial.

ISSN:0020-7179    

DOI:10.1080/00207178908559734

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Traditional modelling notions presume the existence of a ‘truth’ model that relates the input to the output, without advanced knowledge of the input. This has led to the evolution of education and research approaches (including the available control and robustness theories) that treat the modelling and control design as separate problems. This paper explores the subtleties of this presumption. A detailed study of the nature of the modelling errors is useful to gain insight into the limitations of traditional control and identification points of view. Modelling errors need not be ‘small’ but simply ‘appropriate’ for control design. Furthermore, the modelling and control design processes are inevitably iterative in nature.

ISSN:0020-7179    

DOI:10.1080/00207178908559735

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Reduced order models which preserve the firstqMarkov parameters and the firstqcovariances are calledq-Markov covariance equivalent realizations (q-Markov COVERs). This paper extends these notions to the case where the input is coloured instead of white noise. We call this the ‘weightedq-Markov COVER’.

ISSN:0020-7179    

DOI:10.1080/00207178908559736

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor