摘要:

A decentralized model reference adaptive control for a class of large-scale inter-connected systems is developed. The proposed scheme does not require identification of the system parameters, or satisfaction of perfect model-following conditions (PMFC). The boundedness of the output error and the controller parameters is guaranteed using Lyapunov stability theory. The effectiveness of the developed algorithm is demonstrated using a numerical example.

ISSN:0020-7179    

DOI:10.1080/00207178908559695

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

It is shown that the Krylov–Bogoliubov methods that give the approximate oscillatory solution of the equationin terms of Jacobi elliptic functions are applicable not only whenc1>0 andc3>0, but also whenc1>0 andc3<0 or whenc1<0 andc3>0. In particular, the most precise of these methods, the Christopher-Brocklehurst method, is discussed in detail. Its accuracy has been improved by utilizing the transformation properties of elliptic functions with respect to their parameters.

ISSN:0020-7179    

DOI:10.1080/00207178908559696

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

After a brief survey of the relations between time and frequency domain representations of the observer-based linear state feedback loop, the parameterization of the reduced-order compensator is discussed. It is shown that the free design parameters are the coefficients in the polynomial matricesand,characterizing the closed-loop dynamics in the frequency domain. Starting from these polynomial matrices, the doubly coprime fractional representations of the system and of the compensator transfer matrices can directly be computed without recurrence to the time domain results. From these representations the right and left coprime compensator matrix fraction descriptions can easily be evaluated using standard algorithms.

ISSN:0020-7179    

DOI:10.1080/00207178908559697

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Lyapunov functions have been derived for various authors to study the stability of solutions for certain fourth-order non-linear autonomous differential equations. Cartwright (1956) has studied (1) and (2) applying the method of analogy with linear systems, Ku (1964) has proposed a matrix method to study (3) and Skidmore (1966) has derived another Lyapunov function for (1) applying an extension to the method proposed by Leighton (1963). The intrinsic method proposed by Chin (1988 a, b) is applied to derive the Lyapunov functions obtained by Cartwright, Ku and Skidmore. Further, new Lyapunov functions are derived for (1), (2) and (3) applying the intrinsic method that are shown to be far less restrictive than those obtained by the various authors in the literature.

ISSN:0020-7179    

DOI:10.1080/00207178908559698

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A discrete version of Foster's reactance theorem is developed and, subsequently, used to delineate necessary and sufficient conditions for a given polynomial with complex or real coefficients to be of the Schur type. These conditions, obtained from the decomposition of a polynomial into its circularly symmetric and anti-circularly symmetric components, facilitate the construction of stability domains for a family of polynomials through the use of linear inequalities. These results provide the complete discrete counterpart of recent results for a family of polynomials which are required to be tested for the Hurwitz property.

ISSN:0020-7179    

DOI:10.1080/00207178908559699

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The multirate sampled-data control of a linear time-invariant continuous-time plant is considered. It is shown that ‘gain variable’ multirate controllers can be viewed as finite impulse response (FIR) filters, and the pole assignment problem is studied from this viewpoint. Furthermore, it is shown how to evaluate the controller coefficients and how to improve the behaviour of the closed-loop system with respect to limit cycles and steady-state accuracy by introducing integral action.

ISSN:0020-7179    

DOI:10.1080/00207178908559700

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A design procedure is outlined for a simple enhancement to multivariable feedback control systems which may be designed on the basis of steady state process gain information alone. Through this enhancement, consistently better performance is attained in terms of the closed-loop response of the system outputs. A number of examples of the application of this enhancement are given using both simulation and singular value analysis to quantify the performance. The design procedure is very direct and provides a cost-effective means of improving control system performance.

ISSN:0020-7179    

DOI:10.1080/00207178908559701

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A ‘universal adaptive controller’ is a single adaptive controller that can automatically accommodate a significant range of plants having different structures. In this paper, a family of three universal adaptive controllers is presented, one for each of the three cases: first-order plants, second-order plants, and third-order plants. The family of universal adaptive controllers presented here is rather novel in the respect that each controller is all-linear and completely time-invariant. Numerous examples and simulation results are presented to illustrate the ‘universality’ of the proposed adaptive controllers.

ISSN:0020-7179    

DOI:10.1080/00207178908559702

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The problem of representing a class of non-linear systems by both left and right bounded-input-bounded-output (BIBO) coprime factors is studied. Based on the coprime factorizations, the class of all stabilizing controllers of a particular structure for the set of plants under consideration is then characterized in term of a BIBO stable map,Q.The results specialize to the Youla-Kucera parametrization in the linear case. Results giving the various conditions for a non-linear feedback system to be well posed are also presented.

ISSN:0020-7179    

DOI:10.1080/00207178908559703

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Loop transfer recovery (LTR) techniques are known to enhance the input or output robustness properties of linear quadratic gaussian (LQG) designs. Here, novel loop recovery techniques are applied to LQG designs based onH∞/H2optimization methods. The motivation is to exploit the power of theH∞/H2approach so as to avoid high estimator or control loop gains, to cope systematically with non-minimum phase plants, and to maintain availability of the optimal state estimates when required. In the new methods, the simplicity of the original loop recovery approach is retained, in that a scalar parameter can be adjusted to achieve a compromise between optimality for the nominal plant model and robustness at the plant input or output. There is also a built in frequency shaping in the sensitivity function-based performance index used for theH∞/H2optimization. This emphasizes crossover frequencies. However, in our method there is an increase in the controller complexity of at most 2n–1 (nbeing the order of the plant), unless controller reduction techniques are applied.

ISSN:0020-7179    

DOI:10.1080/00207178908559704

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor