摘要:

The identification problems of distributed-parameter systems (DPS) is dealt with, A special method of data collection by using moving sensors is proposed. The sensors are ‘intelligent’ in the sense that they are able to track the positions of the exiremum values of a system state at each time instant. It is shown how to reduce the identification problem for DPS to that of identifying a certain system described by ordinary differential equations (ODE). The proposed approach is applicable to the DPS described by quasi-linear partial differential equations of the hyperbolic type. Attention is focused on the problem of reduction, while the identification of the resulting ODE is not considered in detail, since it is an easier task.

ISSN:0020-7179    

DOI:10.1080/00207178908953451

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Any stationary time-series can be decomposed by means of an optimization operator, called the ζ-optimator, into several components (the time-series){Yti}, i =1,2,…, p, such that the first component {Vti} t = 1,2,…,v is a smooth process having a larger autocorrelation in comparison with the original process {Yt}, i.e. ρvi> ρy. Usually only a few such components are sufficient for approximating the time-series with good accuracy. The ζ-optimator involves a shape parameter a, so the decomposition is unique provided that a. is fixed. Since the component {Vt1} involves much of the useful information it can be used for computing predictors for control purposes. Thus, given the observations Yv, Yv-1, Yv-2,…, a predictor of Yv+1is ρviVv1(q) where, Vv1(q) = qYv+ q(1-q)2Yv-2, …, the weights q(1-q)r, r=0,1,2,…, decreasing rapidly as q = q(α) ϵ (0,1) Further, one may chooseqrather than choosing α, sinceq(α)is a one-one mapping. Onceqis fixed, the predictor ρv1Vv1(q) is obtained in a straightforward way by using the formula above. It is shown that ρv1Vv1(q) converges to the best predictor as α → 0. Some examples are worked out, illustrating both the decomposition and the forecasting procedures.

ISSN:0020-7179    

DOI:10.1080/00207178908953452

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effects of sampled-data control on continuous-time linear stochastic systems are considered. For such systems the state covariance will vary during the sampling periods. Algorithms to compute this time-varying matrix are given. Due to this time variation, an averaged value of the covariance mairix is also introduced. Plants including an arbitrary time delay are accepted. Reasons for the intersample variance alterations are finally illustrated by two examples.

ISSN:0020-7179    

DOI:10.1080/00207178908953453

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The problem of stochastic control is considered for linear discrete-time systems with Markovian jump parameters, where the parameters are included in both state and observation models and their evolutions are not observed. When applying a multiple-model adaptive control (MMAQ strategy to the problem, we need in generalmNsequences of control gains, where m is the number of Markov-chain states andNis a final time. This approach is clearly impractical for largeN. A suboptimal control method is proposed to alleviate the computational loads of the MMAC approach. Algorithms for the elemental control gains are obtained in lerms of a set of m coupled Riccati-like equations, while a generalized pseudo-Bayes algorithm (GPBA) is used for the elemental filter mechanism. Simulation results are included to illustrate the effectiveness of the proposed method by comparing with some MMACs using other elemental filtering techniques.

ISSN:0020-7179    

DOI:10.1080/00207178908953454

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A design method is introduced for regulators using state feedback with specified stability margin and gain constraints. The method offers design parameters which may be used in enhancing the system robustness as well as modifying the maximum absolute values of selected variables, such as control inputs, state variables, or output variables. An illustrative example is included.

ISSN:0020-7179    

DOI:10.1080/00207178908953455

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

GivenAϵ ℂn + nand ϰ ⊂ ℂ, we search for a criterion assuring that the spectrum ofAis clustered in ϰ, σ(A)⊂ ϰ One approach to root clustering is the linear matrix equation, whose half plane version dates back to Lyapunov. The existing literature deals with an algebraic region defined by a single polynomial. In this paper, we construct a novel linear matrix equation related to the intersection of algebraic regions. This considerably enlarges the family of regions with root clustering criteria.

ISSN:0020-7179    

DOI:10.1080/00207178908953456

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A method for predicting the adaptation rate of a single-input, hyperstability-based, MRAC system is developed. Assuming a slowly changing input and output, this rate follows well-defined root loci. A straightforward method for choosing adaptation gains results. The derived theory was applied to a laboratory experiment which involved a DC motor driving an inverted pendulum. Here, the adaptation rates were accurately pedicted in spite of imperfect model following due to the presence of unmodelled static friction.

ISSN:0020-7179    

DOI:10.1080/00207178908953457

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The stabilization of input-delayed systems with saturating actuator is discussed. Three kinds of analogue controllers and three kinds of digital controllers are employed to treat this control problem. Sufficient conditions are derived to guarantee the stability of the systems under control. Each of these conditions expressed by a scalar inequality permits the estimation of the transient behaviour of the controlled system.

ISSN:0020-7179    

DOI:10.1080/00207178908953458

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

We prove convergence, with estimates of the rate of convergence, of iterative schemes for discretized versions of systems of parabolic quasi-variational inequalities (QVI). These parabolic QVI arise in problems of stochastic optimal control with discrete control actions (switchings) where the cost functional involves discrete switching costs in addition to continuous rates of cost. We consider two kinds of discretization: discretization with respect to the space variables, and discretization in both time and space.

ISSN:0020-7179    

DOI:10.1080/00207178908953459

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The trajectory-tracking control problem is considered for a one-link flexible arm described by a non-linear model. Two meaningful system outputs are chosen; namely, the joint angle and the angular position of a suitable point along the link. The common goal is to stiffen the behaviour of the flexible link with respect to the chosen output. Based on the input-output inversion algorithm, a state-feedback control law is designed that enables exact tracking of any smooth trajectory specified for the output. In the closed loop an unobservable dynamics naturally arises, related to the variables describing the arm's distributed flexibility. Joint-based design is shown to be always stable, whereas in the link-point design the closed-loop dynamics may become unstable depending on the location of the output along the link. Open- versus closed-loop strategies are developed and compared. Extensive simulation results are included.

ISSN:0020-7179    

DOI:10.1080/00207178908953460

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor