摘要:

The problem of identifying a single-input, single-output linear discrete-time system, where the output data are corrupted by additive noise, is considered. Use is made of the fact that a consistent estimator may be obtained by compensating an asymptotic bias on the least-squares estimator. The algorithm proposed in this paper is useful in the case when the variance of the noise is not known and on-line computation is required. It is shown that the algorithm generates an estimate asymptotically equivalent to that which minimizes an approximation to the sum of squared output errors. The minimization problem can be reduced to the eigenvalue problem. The experimental results of digital simulation are presented to illustrate the usefulness of the approach and to verify the validity of the theoretical discussions. A comparison with the instrumental variable method proposed by Wong and Polak (1967) is also made. The experimental comparison shows that the performance of the proposed estimator is comparable to that of the optimal on-line instrumental variable method.

ISSN:0020-7179    

DOI:10.1080/00207177708922235

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The first part of this paper surveys controllability and degeneracy results for linear time-invariant delay systems and discusses their relationship to minimal time, delay feedback control. In the second part a now construction for augmented delay feedback which achieves function space null controllability is presented. New results on the pointwise degeneracy of dynamic systems with pure delays are also stated.

ISSN:0020-7179    

DOI:10.1080/00207177708922236

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

An on-line digital computer scheme that generates time-suboptimal control policies for discrete systems is described. The scheme is based upon solving the minimum-effort discrete problem using linear programming, where the number of sampling periods used depends on the available computation time. It is established that the suboptimal control policies generated through that scheme result in transferring the discrete system from any initial state to the origin in a finite number of sampling periods. Furthermore, the time delay that resulted from the usage of an on-line digital computer is overcome by incorporating a feedback signal to control the system during the first few sampling periods. Computational results are furnished to illustrate the efficacy of the proposed suboptimal policies.

ISSN:0020-7179    

DOI:10.1080/00207177708922237

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Based on the Jury and Lee criterion, two new graphical methods to determine the stability bounds for non-linear multivariable systems are developed. It is shown that Cook's multivariable circle theorem is a special case of the first method. The methods are best used on an interactive graphics terminal. Examples are given to illustrate the computational procedure.

ISSN:0020-7179    

DOI:10.1080/00207177708922238

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Let a square invertible rational matrixG(s)be given, and lot it arise from a system matrixP(s). Then a system matrix[Pcirc](s)can easily be found which gives rise toG−1(s). Some of the properties of[Pcirc]are derived here from corresponding properties ofP.

ISSN:0020-7179    

DOI:10.1080/00207177708922239

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

This paper is concerned with an automatic procedure for the inversion of rational matrices. The method which is presented is based on a state-space representation.

ISSN:0020-7179    

DOI:10.1080/00207177708922240

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The concept of[σ1, σ2,.σr]integral left invertibility for linear time-invariant multivariable systems with arbitrary but known initial state is introduced. A necessary and sufficient condition for a given system to be[σ1, σ2,...σr]integral left invertible is proposed. An algorithm for constructing a[σ1, σ2,...σr]integral left inverse system is presented.

ISSN:0020-7179    

DOI:10.1080/00207177708922241

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

This paper is concerned with the stability analysis of interconnected systems composed of locally and globally exponentially stable subsystems. Sufficient conditions for not necessarily asymptotic and exponentially asymptotic stability are derived. The problem of estimating the stability region of the composite system is also considered.

ISSN:0020-7179    

DOI:10.1080/00207177708922242

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The input raw material to a waste-water treatment plant exhibits large, and generally poorly quantified, variations with time. In particular, rainfall run-off can cause gross overloading of the treatment processes of the plant. For a proper operational control of the plant, and hence the quality of the receiving river's water, it would be extremely useful to have advance (short-term) estimates of the effluent flow from the sewer network, i.e. the influent to the plant. This paper studies the feasibility of using an on-line adaptive predictor in such a capacity. The procedure is divided into two steps : (i) the parameters of a multiple input/single output time-series model are recursively estimated at each time-step by the method of least squares ; (ii) a forecast of the plant influent flow is then made on the basis of the newly updated prediction model. Results are presented for data from a treatment plant in Stockholm, Sweden. These demonstrate the adaptability of the predictor to unknown changes in the process dynamics when no information is assumed to be available for rainfall events occurring over the urban land surface,

ISSN:0020-7179    

DOI:10.1080/00207177708922243

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The parameter identification problem in systems governed by partial differential equations is investigated. Stochastic approximation algorithms are applied for identifying a class of distributed systems driven by random inputs and observed through noisy measurements. No restrictions about the probability distributions are imposed. These algorithms converge with probability one, and are suitable for on-line applications. The proposed identification method assumes that a previous system classification has been performed, such that the model to be identified is known up to a set of space-varying parameters, where extraneous terms may be included. The very real case of noisy measurements taken at a limited number of discrete points Located in the spatial domain is considered.

ISSN:0020-7179    

DOI:10.1080/00207177708922244

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor