摘要:

In this paper the inverse Nyquist stability criterion, for single-input single-output linear feedback sy3tems, is generalized to the multi variable case. This is based on an association of a transfer function matrix with a set of inverse Nyquist diagrams, which will be termed the inverse characteristic gain loci. A simple example is given to illustrate the stability tests, and also to show how the inverse characteristic gain loci may be used in feedback system design

ISSN:0020-7179    

DOI:10.1080/00207177708922313

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A new approach to the approximate solution of the non-linear differential equation x¨ + x + px3+ μ/(x,ẋ,t) = 0 is described, which is not subject to the difficulties of interpretation encountered previously. This solution method is compared with the K-B technique, and numerical results are presented to indicate general solution characteristics for − l<p≤100. The possible mechanism for some apparently anomalous behaviour in the relative error of the two methods is considered in detail. It appears likely that a fortuitous combination of phenomena may, in some instances, yield a K-B solution that exceeds the corresponding elliptic function approximation in accuracy when the system is quasi-linear. When the coefficient p is significantly greater than unity the K-B method fails, whereas the elliptic function approximation continues to improve in accuracy as p increases.

ISSN:0020-7179    

DOI:10.1080/00207177708922314

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The problem of designing an observer for generating suboptimal controls for a linear discrete-time regulator when some of the plant state variables are not accessible is considered. The procedure is based essentially on a minimization of the resulting increase in cost. The dependence of this performance measure onw(0), the un-measurable part of the initial plant state vector, is eliminated by averaging the performance obtained for a linearly independent set of values forw(0). The design of the optimal observer is then carried out by minimizing this average value. This procedure is also shown to ensure the stability of the overall system

ISSN:0020-7179    

DOI:10.1080/00207177708922315

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

It is proved that both in the discrete-time and the continuous -time case the asymptotic form of the Kalman filter that is obtained by letting the variance matrix of the initial state go to infinity is minimax with respect to the initial state if the latter is regarded as an unknown, deterministic quantity

ISSN:0020-7179    

DOI:10.1080/00207177708922316

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

This paper considers the problem of designing a state feedback controller to match exactly the transfer-function matrix of a given system to that of a desired model. Necessary and sufficient conditions arc established for exact matching while the design of the appropriate controller is reduced to that of solving alinearsystem of equations. The proposed computational technique simplifies the design significantly and can readily be applied to large-scale systems

ISSN:0020-7179    

DOI:10.1080/00207177708922317

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The problem of simultaneous assignment of closed-loop eigenvalues and eigenvectors using constant complete state-feedback controller is discussed.

ISSN:0020-7179    

DOI:10.1080/00207177708922318

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Regarding the ratios of transfer conductances to transfer susceptances as small parameters, the perturbation method is applied to construct a Lyapunov function for analysis of the transient stability of power systems. The Lyapunov function obtained here takes into account some part of the transfer conductances in the power system network. By using this Lyapunov function the transient stability of a practical power system with non-negligible transfer conductances is analysed. The results are shown in terms of the critical fault clearing time and are consistent with those of simulations

ISSN:0020-7179    

DOI:10.1080/00207177708922319

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Explicit algebraic expressions for the minimum-time isochronal surfaces for certain third-order systems with real eigenvalues and a single saturable control input are presented in this paper.

ISSN:0020-7179    

DOI:10.1080/00207177708922320

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

This paper presents a design procedure for single-loop sampled feedback systems in which the plant transfer function has prescribed bounds on its parameters. The plant is imbedded in a ‘ two-degree-of-freedom system’, which is to be designed such that the system time response to a deterministic input lies within specified boundaries. The design procedure is based on frequency concepts. The time-domain tolerances are translated into equivalent frequency response tolerances. The latter lead to bounds on the loop-transmission L(jv) [v=tang (π/WS)[, in the form of continuous curves on the Nichols chart. However, due to inherent theoretical difficulties existing in sampled feedback systems, it might happen that no L(jv) can be found so that the design specifications of the problem are achieved. The design procedure is transparent enough to guide the designer in which direction to change the specifications of the problem so that the next trial design will be successful.

ISSN:0020-7179    

DOI:10.1080/00207177708922321

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

An optimal stochastic feedforward-feedback control scheme is implemented on a heat exchanger-stirred tank system using an on-line minicomputer. Because variations in the measured disturbance variable affect the process output (controlled variable) before the compensating action can become effective, the feedforward action must be predictive in nature. Statistical time series models are used to model both the measured and unmeasured disturbances in the system. These stochastic disturbance models and the transfer-function models for the process are identified, fitted and checked using statistical model-building procedures on a set of data collected on-line using the minicomputer. The predictive feedforward-feedback controller is derived from these models. The performance of this control scheme is compared with that of an optimal feedback scheme and the actual on-line performance is shown to conform well to the theoretical predictions

ISSN:0020-7179    

DOI:10.1080/00207177708922322

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor