摘要:

This paper outlines the development of the most general representation of a system incorporating only one nonlinear element, and establishes a direct relationship between the pattern of the frequency response and the structure for systems incorporating one nonlinear element having a single-valued odd characteristic. The patterns of frequency response obtained from digital simulations of a number of nonlinear systems illustrate the efficacy of this relationship in identifying the structure of such systems.

DOI:10.1049/ip-d.1980.0013

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A method for analysing the structural identifiability of linear, time-invariant compartmental models in terms of normal modes is presented and applied to several examples. The equations to be examined are linear or bilinear, whereas previous methods have produced nonlinear equations. In consequence, the proposed method has the advantage that is possible to check relatively easily, by a process readily computerised, whether a unique solution exists. Also, if a proposed experiment does not result in auniquesolution, it is clear how the model or the experiment must be modified to achieve this.

DOI:10.1049/ip-d.1980.0014

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The position-control systems for dynamically positioned vessels include wave filters to remove the wave motion signals. These ensure that the sytem only responds to low-frequency forces that would cause the vessel to move off-station. Several filters have been proposed and used in this role, and in the following discussion the Kalman filter is considered. The Kalman filter depends upon the model of the vessel, and the development of such a model is described. Simulation results are given to illustrate the performance of the filter and the performance of the combined Kalman filter and optimal state-feedfack control system.

DOI:10.1049/ip-d.1980.0015

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Previous results on the reduction of single-input/single-output systems are extended to the case of square invertible multivariable systems. It is shown that such systems have a unique decomposition in the form of a forward and a feedback path each having special properties relating to the invariant zeros of the original system. Under certain generic conditions, this decomposition can be extended to yield a representation of the system as a nested sequence of feedback ioops. This provides a convenient method of deriving reduced-order models, which will give good matching of the asymptotic system root locus and open-and closed-loop system dynamics, and hence will be a valid tool in closed-loop controller design.

DOI:10.1049/ip-d.1980.0016

出版商:IEE    

年代:1980

数据来源: IET

摘要:

This paper deals with the design of proportional and derivative (p.d.) controllers in order to assign the poles of a linear multivariable system. It is shown that, for almost all reachable and observable systems given by a triplet (A,B,C), whereAεRn.n,BεRn.randCεRm.n,vpoles can be assigned arbitrarily close tovspecified symmetric values, wherev= max {min(n, 2r + m− 1), min (n, 2m + r − l)}−l, with 1≥0, so thatldegrees of freedom are disposable and can be used to locate the remainingn–vpoles in a specified region of the complex plane. Examples are included for illustration.

DOI:10.1049/ip-d.1980.0017

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The paper gives a review of pole-placement design for systems with known parameters, then focuses entirely on the servos. Adaptive pole-placement algorithms are discussed, leading to the formulation ofexplicitandimplicitschemes, and simulation of the behaviour of the alorithms is given.

DOI:10.1049/ip-d.1980.0018

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Modern microprocessor capabilities permit the control designer to consider using relatively complicated nonlinear control algorithms, which would have been considered impractical in the past. The paper presents the results of a study of the potential usefulness of nonlinear decoupling algorithms for the design of excitation and governor controllers for a power system using state-variable feedback. A control law for decoupling rotor angle and field flux is derived. For the rejection of load disturbance, the design of a servocompensator consisting of strings of integrators in the outer ioop around the decoupled inner loop is proposed. The closed-loop system is shown to be asymptotically stable. The system can be transferred to a new operating condition corresponding to any desired terminal voltageVtand tie-line powerPtieThe simulation results using a first-order compensator show that system asymptotically tracks the desiredVtandPtieunder unknown piecewise constant disturbances. Results show good transient and steady-state responses in rotor angle, field flux and frequency. Steady-state errors inVtandPtieowing to parameter uncertainty are reduced to zero by changing the command inputs using an external loop. The effect of stochastic load on the response is small.

DOI:10.1049/ip-d.1980.0019

出版商:IEE    

年代:1980

数据来源: IET

摘要:

In this paper, we develop a decentralised controller for large-scale linear interconnected dynamical systems by using, for each subsystem, a low-order model for the interactions. The output of the interaction model is improved online using a model-following technique. The controller gains are calculated only once, and they are easy to compute since all operations are done subsystem by subsystem. A sufficient condition is also developed for the stability of the global system with the decentralised control subject to structural perturbations. It is seen that satisfaction of this condition provides a robust design which is insensitive to structural perturbations.

DOI:10.1049/ip-d.1980.0021

出版商:IEE    

年代:1980

数据来源: IET