摘要:

A formulation is presented, based upon algebraic systems theory, to deal with the problem of robustness under combined parametrical and/or structural changes in the plant. The key design objective is the maintenance of the dominant closed-loop poles close to their nominal values, while prescribing their placement due to the un model led dynamics to the subsets of the complex plane, which have small influence in the system response. The mathematical framework is the ring of polynomial matrices for input-output descriptions and its relationships with the rational transfer matrix fraction descriptions.

ISSN:0020-7721    

DOI:10.1080/00207728908910244

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A new scheme for the optimal control of nuclear power plants is proposed. It differs from previous applications of optimal control theory to nuclear reactors in that here it is possible to select the weighting matrices in the quadratic cost functional so that desired pole placement, and subsequent transient response, is achieved. The desired weighting matrix and corresponding optimal control law are found sequentially. From the computational point of view the proposed design algorithm is very efficient since the dynamical system is aggregated at each stage of the sequential process to a first- or a second-order system. Thus, almost the entire computation involves second- or fourth-order matrices.

ISSN:0020-7721    

DOI:10.1080/00207728908910245

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A method for constructing a reduced-order model retaining the internal structure of original high-order cascade connected and feedback structured systems is derived by the Mullis-Roberts algorithm. The reduced-order model obtained here is the optimal approximation in the sense that it minimizes the curvilinear integral of the squared norm of an approximation error at the unit circle of the 2-plane. The algorithm for obtaining the reduced-order models is described. One feature of the proposed algorithm is that it is possible to compute reduced-order models of each subsystem independently. The stability of the reduced-order model is not always guaranteed. However, the results of numerical computations show that the reduced-order systems remain stable for almost all randomly selected examples and approximate the input-output behaviour of original systems fairly well.

ISSN:0020-7721    

DOI:10.1080/00207728908910246

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The modelling and learning control of a phosphate drying furnace is considered. A mathematical model derived from mass and energy considerations is presented. This model consists of four hyperbolic partial differential equations. The numerical model simulation is performed using the method of characteristics, with the fuel flow and moisture content of the dried phosphate selected as control variables. Despite the external perturbations acting on the drying process, the main control objective is to minimize the fuel consumption and to keep the moisture content of the dried phosphate less than or equal to a certain value, provided that the temperature of the hot air, used as purging gas, equals or exceeds the saturation temperature. This control problem is modelled as the behaviour of a learning automaton in a random environment, subject to mean constraints. Using a reinforcement scheme, the automata update their action probabilities according to the response of the environment, and improve their behaviour with time. Detailed computer simulation results, which demonstrate the performance of this automaton controller, are presented.

ISSN:0020-7721    

DOI:10.1080/00207728908910247

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The parameterization of MIMO systems in the open-loop balanced representation was introduced by Kabamba (1985) to show the advantages of using the balanced canonical form over other classical canonical forms as regards the guaranteed stability and minimality of the representation. The parameterization of MIMO systems in closed-loop balanced representation is introduced: the stability is guaranteed under particular conditions and the minimality is also assured. The importance that such a type of realization plays is fundamental in the synthesis of MIMO systems with assigned characteristic values; this allows us to investigate, for example, the stability of closed-loop systems with a low-order regulator. Indeed, for a defined class of MIMO systems, the introduced parameterization allows us to derive sufficient conditions for the closed-loop dissipativeness and for the stability of the reduced-order compensator, generalizing some results proved for S1SO systems.

ISSN:0020-7721    

DOI:10.1080/00207728908910248

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Some of the solution properties of an nth order single input-output system with bounded control in which the coefficient of the highest order derivative is a small parameter ε are discussed. In particular, the reachable set from the origin for this system can be approximated to within O(ε), as ε → 0 by reachable sets constructed from either of two (n — l)-dimensional systems. These approximating systems arise in a natural way, the first by a natural partitioning of the original system matrix and the second by setting ε = 0. The results have particular significance in the case n = 3.

ISSN:0020-7721    

DOI:10.1080/00207728908910249

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A geometric approach is used to demonstrate that Pulse-Width-Modulation (PWM) controlled systems exhibit perturbation invariance properties identical to those exhibited by dynamical systems undergoing sliding motions on discontinuity surfaces. At the core of the result is the existence of an ideal equivalence among sliding regimes of Variable Structure Feedback (VSF) control and Pulse-Width-Modulated (PWM) control responses.

ISSN:0020-7721    

DOI:10.1080/00207728908910250

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A robust adaptive algorithm for system identification and adaptive signal processing is derived. The algorithm can be viewed as a combination of the output-error-type and equation-error-type identifiers. No distributional assumptions on the noise term have been made. This approach allows computational advantages in obtaining the estimates, and it also allows us to identify any structural change.

ISSN:0020-7721    

DOI:10.1080/00207728908910251

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

For Schur polynomials with perturbed coefficients, a lower bound is derived for the radius of the hypersphere in the parameter space, within which the perturbed polynomials retain the Schur property. The result is obtained via the Lyapunov matrix equation and is expressed in terms of the size of the solution lo the equation This enables us to estimate the allowable size of the perturbation simply by solving the equation.

ISSN:0020-7721    

DOI:10.1080/00207728908910252

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The profit analysis of a single server two-unit (one priority and the other ordinary) cold standby system with two modes normal and total failure is examined. The priority unit gets preference both for operation and repair. Whenever an operative unit fails, a delay occurs in locating the repairman and getting him to the system location due to certain administrative actions with known probability p. The system is observed at suitable regenerative epochs in order to obtain several economics-related reliability characteristics. Explicit results are obtained in a few particular cases.

ISSN:0020-7721    

DOI:10.1080/00207728908910253

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor