摘要:

Maxwell's manuscripts held at Cambridge University Library contain several items of interest from a control or stability point of view. The extract reproduced in this paper consists of a draft of the first half of Maxwell's essay on the stability of the motion of Saturn's rings. Historical notes are added on the development of stability theory before Maxwell's essay.

ISSN:0020-7179    

DOI:10.1080/00207178208932916

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The decentralized control of discrete time stochastic linear systems is considered in this paper. The decentralized control laws are obtained by determining a sequential Nash equilibrium point for a set of quadratic cost functions. In the absence of disturbances, the Nash equilibrium set has the property of driving the state of the closed-loop system to the origin in finite time or asymptotically. In addition, the control law is a linear function of the instantaneous output measurements and can be computed on-line using relatively simple algorithms.

ISSN:0020-7179    

DOI:10.1080/00207178208932917

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A weighted minimum-variance controller has recently been defined which is based upon ak-steps-ahead control law and which may be used for unstable and non-mimimum-phase plants. The controller includes control weighting and this results in relatively smooth control signals. The controller is also stable for ranges of control weighting where other control laws are unstable. Both explicit and implicit self-tuning algorithms are proposed based upon this controller. Some of the algorithms use bilinear identification methods developed by Åström for use in his pole-zero-placement algorithms. The self-tuning controller is related to that developed by Clarke and Gawthrop when the system is minimum-phase.

ISSN:0020-7179    

DOI:10.1080/00207178208932918

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A new approach is presented for designing multivariable PI-controllers, which are robust according to structural as well as parametrical model uncertainties. The algorithm starts with the regulator design by means of the well known optimal control procedure ignoring the model uncertainties. Then the input-output behaviour of the closed-loop original system is approximated using a majorization of the model error. It is shown, that the robustness requirements provide certain limitations on the controller matrix and hence on the weighting matrices in the performance index. These results lead to an instructive design algorithm to find a compromise between the fulfilment of the given requirements on the input-output behaviour and the robustness properties according to the model uncertainties.

ISSN:0020-7179    

DOI:10.1080/00207178208932919

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

After expressing the response of a bilinear dynamical system in terms of a Volterra series, the filtering properties of the system are characterized in the frequency domain. The zero harmonic component of the output of a closed-loop system comprised of the bilinear system and a static relay non-linear element is approximated using basic second-order Volterra kernels. This allows estimation of bilinear system parameters based upon measurements of the average value of the closed-loop system output.

ISSN:0020-7179    

DOI:10.1080/00207178208932920

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A method for approximating high order stable systems via lower order stable models is presented. It is an improvement over previous Routh-Padé methods since the denominator polynomial of the model transfer function, even if based on the elements of a Routh array, contains two free parameters. A systematic procedure is illustrated for evaluating, besides the numerator coefficients, such denominator parameters in order to ensure a good fit, in the Padé sense, and a suitable stability margin.

ISSN:0020-7179    

DOI:10.1080/00207178208932921

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

We present a new approach to two filter smoothing formulae via diagonalization of the general time variant hamiltonian equations of the linear estimation problem. This approach shows the special role of the famous Mayno-Fraser two filter formulae and also provides insight into certaini nvariance properties of backwards Kalman filter estimates.

ISSN:0020-7179    

DOI:10.1080/00207178208932922

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

This paper deals with necessary optimality conditions for control of general linear retarded systems to small solutions. Here the final states at timeTare required to generate small solutions of the uncontrolled system vanishing afterT − h + α, where α ≥ 0 is fixed. This generalizes the fixed final state problem where α = 0, and for α = hincludes problems with fixed reduced final stateFxT, whereFis the structural operator of the delay system. Necessary optimality conditions in the form of a maximum principle are valid if a certain space called the ‘ small attainability sub-space ’ is closed in a Sobolev space. A sufficient criterion for this closedness property is indicated. Finally, an example is discussed where the maximum principle for the fixed final state problem is not valid, while the new problem with α = hcan be solved by an application of the obtained results.

ISSN:0020-7179    

DOI:10.1080/00207178208932923

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

An adaptive control scheme which assigns all poles of an unknown linear discrete system to arbitrary Locations is proposed. Design procedures for both state space and frequency domain are outlined. The scheme is composed of a hyperstable fast identifier and an adaptive controller for adjustment of the feedback gain. It is shown that the overall control scheme is globally hyperstable if the plant input is sufficiently rich.

ISSN:0020-7179    

DOI:10.1080/00207178208932924

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A rational transfer function model of the plant is generally desirable in feedback system design, when only plan input and output data are available over finite, sometimes incomplete, time intervals. This is especially so in a recent exact design technique for highly uncertain time-varying and non-linear plants. Here, the plants are replaced rigorously by an equivalent linear time-invariant plant set. Existing numerical techniques were found inadequate, especially in the high-frequency range, which is important in the design of feedback systems with large plant uncertainty. A technique was developed with excellent results, even for noisy data, unstable and non-minimum phase plants and severely truncated time intervals. The transfer function is calculated directly, without derivation of the input, output signal transforms. The operations involve repeated integrations of the data. Numerous examples are included.

ISSN:0020-7179    

DOI:10.1080/00207178208932925

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor