摘要:

Maxwell's manuscripts held at Cambridge University Library contain several items of interest from a control or stability point of view. The extracts reproduced in Part III consist mainly of a draft of the second half of Maxwell's essay on the stability of the motion of Saturn's rings. Here Maxwell investigates the stability of a fluid ring rotating round a centre of attraction. Two related letters written by Maxwell are also reproduced. Maxwell's claim to the effect that a ring of equally spaced satellites, with equal sufficiently small masses, represents a stable configuration, is shown to be erroneous.

ISSN:0020-7179    

DOI:10.1080/00207178308933042

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Linear system models can be decomposed into reduced-order ‘ fast’ and ‘ slow ’ subsystems using ‘ spectrum separating ’ solutions to dual Riccati type equations. Eigenspace power iterations provide globally convergent iterative schemes for obtaining these solutions. From this basis, an equivalence of previous decomposition techniques is then achieved including the classic two-time-scale asymptotic series decomposition of singularly perturbed systems. The result is a unified theory for the decomposition of time scales in linear systems applicable to both continuous and discrete time models.

ISSN:0020-7179    

DOI:10.1080/00207178308933043

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A new canonical form of multivariable invertible systems is given. This form is suitable for the singular perturbation analysis of such singular problems as multi-variable asymptotic root-loci under high-gain feedback, cheap control, state variable estimation with weak measurement noise, etc. Appropriate selection and decomposition of state variables into slow and fast changing groups is a key feature that loads to well-defined singular perturbation models. The selection of state variables is accomplished without explicitly calculating any eigenvalues of the given system but by knowing the direct relationship of the output and its differential coefficients with the input. The use of the canonical form to characterize the multivariable root-loci under high-gain feedback is demonstrated.

ISSN:0020-7179    

DOI:10.1080/00207178308933044

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The one-dimensional problem considered is the minimization of the functional

ISSN:0020-7179    

DOI:10.1080/00207178308933045

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Two of the most advanced procedures for recursively estimating the parameters in linear, observation space models of stochastic dynamic systems are the prediction error (PE) and optimal generalized equation error (OGEE) methods. This paper discusses the relationship between these methods in the case of the transfer function (TF) or Box-Jenkins model ; and compares their performance in terms of optimality, computational complexity and practical robustness. While the methods are quite similar for the TF model, it is shown that the instrumental-variable inspired OGEE approach yields algorithms that are computationally simpler and more robust when applied in practical situations.

ISSN:0020-7179    

DOI:10.1080/00207178308933046

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The paper gives sufficient conditions for instability of linear systems of both the neutral and retarded types with commensurate and non-commensurate time delays. The conditions are given in terms of time delays and coefficients of the characteristic quasi-polynomials of these systems. Illustrative examples are presented.

ISSN:0020-7179    

DOI:10.1080/00207178308933047

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The paper investigates an infinite-time discrete regulator problem with a two-time-scale property. Sufficient conditions are given for the existence of a suboptimal solution, and a near-optimum design method is proposed via the time-scale decomposition approach. The method reduces the system order and has a mode-decoupling property.

ISSN:0020-7179    

DOI:10.1080/00207178308933048

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Necessary and sufficient conditions for the existence of a solution to the deadbeat servo problem for single-input single-output 2D linear systems are given. An algorithm is presented for finding a control law such that the tracking error vanishes in the shortest time possible. The algorithm is illustrated by a simple example.

ISSN:0020-7179    

DOI:10.1080/00207178308933049

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A new design technique for multivariable feedback systems is presented. In this approach,n—1 open-loop transfer functions at different inputs of the plant, with all other feedback paths closed, are specified in advance, and are achieved exactly. The nth open-loop transfer function is a by-product of the design process, such that the overall feedback system is stabilized. The design approach is fitted to solve problems in which the plant elements can have non-stable poles and non-minimum phase zeros. The design process is straightforward, no iterations are necessary, and the achieved design copes exactly with the design specifications. The gainbandwidths of the different lis and the overall loop gainl*might be constrained due to non-stable poles and zeros of the plant elements. Based on the obtained different loop gains, any input output matrixTcan bo achieved with the aid of an appropriate prefilter matrixF.

ISSN:0020-7179    

DOI:10.1080/00207178308933050

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Dynamical systems which contain several identical subsystems occur in a variety of applications ranging from command and control systems and discretization of partial differential equations, to the stability augmentation of pairs of helicopters lifting a large mass. Linear models for such systems display certain obvious symmetries. In this paper, we discuss how these symmetries can be incorporated into a mathematical model that utilizes the modern theory of algebraic systems. Such systems areinherentlyrelated to the representation theory of algebras over fields. We will show thatanycontrol scheme which respects the dynamical structure either implicitly or explicitly uses the underlying algebra.

ISSN:0020-7179    

DOI:10.1080/00207178308933051

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor