摘要:

The control and stabilization of decentralized systems attracted a great deal of attention in the late 1970s and 1980s, in part because the microprocessor revolution made it feasible to envision the control of large, complex systems. Most of the stability research undertaken during this era was analytic, focusing for example on various interpretations of weak or strong coupling between subsystems, the existence of multiple time-scales, etc. Motivated by the so-called ‘twin-lift’ problem, a problem of stabilizing the motion of two helicopters manoeuvring a single load, we develop a methodology for stabilizing classes of decentralized systems based on a more algebraic approach involving the external symmetries of decentralized systems. The study of the symmetry algebra of classes of such systems was initiated by Hazewinkel and Martin and in this language, we derive stabilizing, local feedback laws for any class of decentralized systems having a semi-simple algebra of symmetries. The twin-lift problem as well as certain problems involving stabilization of discretizations of distributed parameter problems have semi-simple algebras of symmetries.

ISSN:0020-7179    

DOI:10.1080/00207178908559745

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The optimal control of linear differential-difference systems of neutral type with respect to quadratic performance criteria over an infinite time interval is treated. The linear differential-difference systems with delays in coordinates, derivatives, and control actions are analysed. Dynamic programming is used to determine the optimization equations. A set of Riccati type equations is obtained. The closed-loop system synthesis problem is discussed. The approximate optimal problem is formulated. A connection is established between the original and approximate optimal problems. Special attention is paid to the suboptimal system synthesis problem.

ISSN:0020-7179    

DOI:10.1080/00207178908559746

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

We extend the result of Soh to study the zeros of an entire family of polytope polynomials. We show that, under some conditions, zeros of the family of polynomials can be inferred from the zero locations of the vertex polynomials.

ISSN:0020-7179    

DOI:10.1080/00207178908559747

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A wide class of stabilizing adaptive control rules is investigated. The feedback laws combine high gain adaptive procedures with switching functions and stabilize the systems without knowledge of the sign of the high frequency gain. Furthermore, some non-linear structural perturbations are tolerated.

ISSN:0020-7179    

DOI:10.1080/00207178908559748

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The robust control design problem is studied for a class of uncertain dynamical systems. The uncertainty of the system is time varying. The only assumption on the uncertainty is that it is bounded. No statistical property of the uncertainty is ever assumed and utilized. The robust control does not need thea prioriestimation on the bound of uncertainty. An adaptive algorithm for the on-line estimation of the bound is constructed and the robust control is only dependent on this estimation. The adaptive algorithm is a modification of previous work by Corless and Leitmann (1983). The advantages of this new algorithm include a constant control design parameter (which should have been time varying previously) and the applicability to linear systems with mismatched uncertainty and measurement noise.

ISSN:0020-7179    

DOI:10.1080/00207178908559749

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A new design method of regulators using state feedback is developed. This method not only assigns eigenvalues to the closed-loop system, but also assigns parts of the closed-loop eigenvector structure. Illustration of the method, in the case of a two link manipulator, is included. A new robustness measure is introduced.

ISSN:0020-7179    

DOI:10.1080/00207178908559750

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A new approach—a sequence model approximation method—is proposed for determining the optimum steady-state operating point of an industrial process. The method makes full use of first-order information of reality to construct an approximate model which can match real output and the required derivatives of reality at each iteration. In order to ensure that the real objective index descends, the Newton step and a one-dimensional minimization search technique are then used respectively. The approach's convergence and optimality conditions are investigated under mild assumptions. Simulation results show that the new approach requires fewer set-point changes, and exhibits a higher convergent rate than previous methods in this field.

ISSN:0020-7179    

DOI:10.1080/00207178908559751

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

For stochastic control systems described by the ARMAX model with unknown matrix coefficients, the stochastic adaptive control is designed so that the parameter estimates converge to the true values with a rate of convergenceO((logn)(log logn)c/na) with a>0,c>1 and the tracking error tends to its minimum value at a speed ofO(n-1/2e) with e>0.

ISSN:0020-7179    

DOI:10.1080/00207178908559752

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The problem of designing unknown input observers, which is especially meaningful for singular systems because differentiation terms exist in the inputs in the solution, is discussed. The conditions for such observers’ existing and an algorithm for designing the observers under these conditions are obtained and a numerical example is presented.

ISSN:0020-7179    

DOI:10.1080/00207178908559753

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Motivated by numerous potential applications in decentralized estimation, detection and adaptive control, Monte Carlo optimization, etc., two types of stochastic approximation (SA) algorithms with parallel observers are developed. To find the root of a non-linear function with random noise corrupted measurements, instead of employing the classical Robbins-Monro (RM) SA procedures with a single observer, a collection of physically separated parallel observers are used to estimate the same parameter. A newly formed approximation sequence is obtained by means of an appropriate quasi-convex combination of the most current values obtained from all the observers. In addition to getting strong consistency and asymptotic normality, the optimal convex combination coefficients are derived. Comparisons of asymptotic performance are made. These comparisons indicate that the algorithms suggested here are asymptotically better than the classical approach.

ISSN:0020-7179    

DOI:10.1080/00207178908559754

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor