摘要:

Robust control of a synchronous machine via sliding mode techniques is tackled in some detail. Such control laws are well suited for the electric power converter. However, high frequency commutations are avoided due to the mechanical systems. Various recent schemes are studied and operated to derive control solutions which are technically feasible. Robustness is studied with respect to rotor flux uncertainties and to stator resistance which varies with the temperature of the motor.

ISSN:0020-7179    

DOI:10.1080/00207179308923039

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper proposes a design method of robust controllers for a class of systems which contain uncertain nonlinear terms and bounded unknown disturbances. The distinguishing feature of our method is to achieve ( a) model following; ( b) the prescribed error transient response; and (c) the arbitrary tracking accuracy, simultaneously and independently, through the appropriate decoupling of the original control problem. Furthermore, the application of our design method to the robotic control is shown with some illustrative simulation results.

ISSN:0020-7179    

DOI:10.1080/00207179308923040

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper presents an asymptotic output tracking stability proof for a new modification to a direct model reference adaptive control procedure. This modification, which alleviates a very restrictive positive real constraint, greatly expands the class of processes that can now be controlled with zero output error. This paper presents illustrative examples demonstrating the utility of the algorithm.

ISSN:0020-7179    

DOI:10.1080/00207179308923041

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The effects of data pretreatment and mean levels upon nonlinear model structures is investigated. Techniques commmonly used to prefilter data in linear system identification are shown to alter the model structure in the nonlinear case. The effects of mean levels are considered in detail and a new unravelling algorithm is derived to recover the underlying system model when the offsets are external to the system. A new mapping from the time domain to the frequency domain is also introduced for the case where offsets can be considered as an implicit part of the system.

ISSN:0020-7179    

DOI:10.1080/00207179308923042

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Model predictive control (MPC) is a well-established controller design strategy for linear process models. Because many chemical and biological processes exhibit significant nonlinear behaviour, several MPC techniques based on nonlinear process models have recently been proposed. The most significant difference between these techniques is the computational approach used to solve the nonlinear model predictive control (NMPC) optimization problem. Consequently, analysis of NMPC techniques is often connected to the computational approach employed. In this paper, a theoretical analysis of unconstrained NMPC is presented that is independent of the computational approach. A nonlinear discrete-time, state-space model is used to predict the effects of future inputs on future process outputs. It is shown that model inverse, pole-placement, and steady-state controllers can be obtained by suitable selection of the control and prediction horizons. Moreover, the NMPC optimization problem can be modified to yield nonlinear internal model control (NIMC). The computational requirements of NIMC are considerably less than NMPC, but the NIMC approach is currently restricted to nonlinear models with well-defined and stable inverses. The NIMC controller is shown to provide superior servo and regulatory performance to a linear IMC controller for a continuous stirred tank reactor.

ISSN:0020-7179    

DOI:10.1080/00207179308923043

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The paper focuses on the development of techniques for solving control engineering problems by applying heuristic search methods. Two main contributions of the work are: theoretical development of heuristic optimal control and its application to real engineering problems. In the sense that intelligence is an ability which maximizes the possibility of reaching a goal in an uncertain environment, heuristic optimal control is an intelligent control method. The paper provides necessary notation, proofs of the basic theories, and examples of heuristic optimal control.

ISSN:0020-7179    

DOI:10.1080/00207179308923044

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The theory of deterministic model weighting adaptive control is presented and its relation to Multi-model adaptive control is outlined. A pilot process study compares the behaviour of the proposed algorithm to methods such as P1D, dynamic matrix control and adaptive generalized predictive control. Finally an industrial application of the method is described.

ISSN:0020-7179    

DOI:10.1080/00207179308923045

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper outlines how it is possible to decompose a complex non-linear modelling problem into a set of simpler linear modelling problems. Local ARMAX models valid within certain operating regimes are interpolated to construct a global NARMAX (non-linear NARMAX) model. Knowledge of the system behaviour in terms of operating regimes is the primary basis for building such models, hence it should not be considered as a pure black-box approach, but as an approach that utilizes a limited amount ofa priorisystem knowledge. It is shown that a large class of non-linear systems can be modelled in this way, and indicated how to decompose the systems range of operation into operating regimes. Standard system identification algorithms can be used to identify the NARMAX model, and several aspects of the system identification problem are discussed and illustrated by a simulation example.

ISSN:0020-7179    

DOI:10.1080/00207179308923046

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The polynomial equation approachcan be used to solve a variety of important control problems. The approach leads to the requirement to solve linear polynomial equations. We present a new algorithm for the numerical solution of a general coupled pair of linear polynomial equations. The algorithm is based upon the method of polynomial reductions. Theoretically, solving the coupled equations together enhances the numerical robustness of the equation solution. The algorithm finds a specific and unique minimal degree solution of the equations. The general couple of equations studied is representative of a number of problems in linear control theory, and the minimal degree solution usually corresponds to an optimizing solution of the control problem

ISSN:0020-7179    

DOI:10.1080/00207179308923047

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The quantitative feedback theory (QFT) developed by I. M. Horowitz is of recent widespread interest. An extension of traditional feedback principles, QFT provides design methods in the frequency domain yielding prescribed hard constraints on the amplitudes of tracking errors in the time domain. These methods prove significantly more effective than those of the more modern LQ,H2, and H∞theories. Inherent in QFT, however, are several adverse features, in particular, a frequency and time relationship that is partially heuristic, a design process that is highly graphic, and a treatment of SISO, MIMO, linear, and non-linear systems that is somewhat case-dependent. An alternative QFT circumventing these features is the focus of this paper. An alternative deriving from a general formulation in the time domain alone, providing a unified set of amplitude- and computer-oriented design criteria, and yielding prescribed, fully analytic constraints on tracking errors is considered. Specifically, we formulate system stability, design criteria, and tracking constraints in terms of fixed-point conditions in a combined time-domain and L∞setting. These conditions are established by the techniques of homotopic invariance and tailored to the tracking dynamics of feedback systems.

ISSN:0020-7179    

DOI:10.1080/00207179308923048

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor