摘要:

Singular-value analysis is employed in the development of processes displaying good controllability properties. Excess manipulatable variables may be used in the form of internal control loops which enhance the process conditioning, giving improved performance in the primary control loops of a conventional multi-loop control system.

ISSN:0020-7179    

DOI:10.1080/00207178408933331

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

An explicit solution is developed of the matrix equation A(z)X(z) + X(z)B(z) = C(z) where z is a parameter. The approach considered is general in that no particular representations are assumed and the solution X(z) is expressed as a simple function of the matrices involved. As an application, the stability of a class of generalized linear systems is discussed, namely systems which depend polynomially on a real parameter and time-delay systems.

ISSN:0020-7179    

DOI:10.1080/00207178408933332

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper presents an application of the inverse Nyquist array (INA) technique to the design of a multivariable controller for a boiler subsystem. The boiler is a 1.6 MVV water boiler using solid fuel. The subsystem studied consists of the boiler underpressure and the flue-gas oxygen content. First a simple transfer function model based on step response measurements is constructed. The subsystem model is analysed and the interactions are decreased with a constant compensator using Rosenbroek's INA method. Finally, scalar PI controllers are tuned for the approximately decoupled system. A brief description of the microcomputer control system is given. The control system and the designed multivariable controller have worked well since their installation in February 1983.

ISSN:0020-7179    

DOI:10.1080/00207178408933333

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Explicit forms for the transmission operators for a wide class of linear systems subject to control by a class of feedback filter indicate that design may be made on the basis of separate subsystems in the manner associated with state-estimating controllers but realized by an output feedback compensator configuration without input sensing. The results show that an account must be taken of the joint influence that the properties of these separately designed subsystems have on the resulting basic closed-loop transmission operators and indicate directly how the choice of design parameters governs the complete structure of these operators.

ISSN:0020-7179    

DOI:10.1080/00207178408933334

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

In a previous paper (Bensoussan 1984) we have shown that the sensitivity of a single-input single-output minimum-phase system can be reduced below any given positive value over any finite frequency range of interest while not exceeding a global sensitivity bound on the whole frequency domain. We shall use these results in order to study the problem of decentralized control of weakly coupled plants which is also shown to be strongly linked to the problem of sensitivity reduction to external additive noise applied at the output. We propose a scheme of compensation which applies to a family of weakly coupled plants whose diagonal part is minimum phase.

ISSN:0020-7179    

DOI:10.1080/00207178408933335

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A synthesis procedure is developed for a Feedback system consisting of two non-Jinear links : a non-dynamic link v in the plant and a dynamic one—non-linear corrector— consisting of a linear link looped by the link v or by parallel connection of the link — v and a unitary one. Global stability of the system is guaranteed by the absolute stability criterion. It is shown that in such a system the permissible phase shift, of the loop transmission function and then the ultimate achievable feedback in the prescribed frequency band are much larger than those in the conventional absolutely stable single-loop system. The method described is applicable to the band-pass and the low-pass system. Even under the more restricted limitation on the output process (absolutely stable), the benefit in the feedback in the proposed system is remarkable. Examples are included to illustrate the procedure.

ISSN:0020-7179    

DOI:10.1080/00207178408933336

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

An explicit self-tuning controller is described that incorporates closed-loop pole location as the principal design criterion for the objective function of Clarke and Gawthrop. The algorithm includes several minor extensions to improve robustness : a variable dead-time compensator to deal with unknown or time-varying delay, and a method of treating steady-state offset that avoids retaining an integrator in the loop continuously. A new technique has been developed and included in the algorithm that enables the controller to be auto-tuning in the sense that the closed-loop pole(s) and sampling period can be determined on-line so as to optimize the system set-point step response, leaving the system designer to specify only internal model orders and noise characteristics on which to initiate retuning. The resulting controller is quite robust and can easily handle unstable, non-minimum phase systems in a single-loop configuration, as is demonstrated by several simulations including a non-linear model of a fixed-bed autothermal reactor operating over such a large range that auto-tuning of the poles is a necessity.

ISSN:0020-7179    

DOI:10.1080/00207178408933337

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper develops multilayer decompositions for an optimal control problem whose solution gives the best controls for a dynamical system subject to known disturbances. Two different types of decomposition are developed, and their limitations clearly described. Some conclusions are drawn for their use on practical problems.

ISSN:0020-7179    

DOI:10.1080/00207178408933338

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The aim of the design method is to find a compensator that results in a ‘ basically non-interactive ’ closed-loop behaviour, for more than one model that claims to represent the same plant. The idea is to construct a nominal diagonal model, which does not necessarily belong to the given family of models, and to consider the members of this family as variations around it. If the precompensator sought is diagonal then the design can be split into a number of single-input single-output designs which are more easily carried out.

ISSN:0020-7179    

DOI:10.1080/00207178408933339

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The paper considers the synthesis of controllers for the feedback control of multi-variable plants with large parameter ignorance. Here, the output response of each loop is required to satisfy some a priori specified time domain tolerance bounds irrespective of the parameter variations of the plant and the interaction carried through other loops. By an interplay between the Nyquist array and Bode array, it becomes possible to obtain a design that not only satisfies the required specifications but also offers some advantages over other design techniques for the same class of problems.

ISSN:0020-7179    

DOI:10.1080/00207178408933340

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor