摘要:

The problem of recursive robust identification of linear discrete-time single-input single-output dynamic systems with correlated disturbances is considered. Problems related to the construction of optimal robust stochastic approximation algorithms in the min-max sense are demonstrated. Since the optimal solution cannot be achieved in practice, several robustified stochastic approximation algorithms are derived on the basis of a suitable non-linear transformation of normalized residuals, as well as step-by-step optimization with respect to the weighting matrix of the algorithm. The convergence of the developed algorithms is established theoretically using the ordinary differential equation approach. Monte Carlo simulation results are presented for the quantitative performance evaluation of the proposed algorithms. The results indicate the most suitable algorithms for applications in engineering practice.

ISSN:0020-7179    

DOI:10.1080/00207178808906231

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The problem of speed control of a DC drive system with a variable moment-of-inertia load has recently been considered for the purpose of comparison of the performance of a non-linear adaptive control system and a classical linear control system. The results of this comparison apparently show that the performance of the adaptive controller is inferior to that of the linear control configuration under non-ideal conditions. This paper uses the same example to show that a simple adaptive controller can easily overcome the difficulties of this test.

ISSN:0020-7179    

DOI:10.1080/00207178808906232

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

From some basic relations in estimation theory, a comprehensive set of formulae are obtained for the periodic solution of Riccati equations. To obtain numerically stable algorithms, square root formulations are introduced. Both the discrete-time and continuous-time cases are considered. Closed-loop properties for periodic systems are also investigated. The results are applied to multirate measurement sampling. The control of a continuous stirred tank reactor serves as an illustrative example. The temperature measurements are then complemented by concentration analysis available at a slower rate than the basic sampling and control rate. The results give some guidelines about the benefits of multirate sampling.

ISSN:0020-7179    

DOI:10.1080/00207178808906233

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Two stable MRAC algorithms for unknown linear discrete-time multivariable plants are presented, under the assumption that the state information is available. Proofs of stability are given and some simulations are carried out to show the applicability of the proposed algorithm.

ISSN:0020-7179    

DOI:10.1080/00207178808906234

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A general solution to the optimal stochastic tracking problem in the presence of both measurable and immeasurable disturbances is obtained using polynomial techniques. The plant under consideration includes a coloured measurement noise signal. In addition, all disturbance and reference sub-systems may be unstable. The problem formulation involves a cost-function which has dynamic weighting elements. A feedforward compensator is incorporated in the optimization procedure for the rejection of the measurable disturbance.

ISSN:0020-7179    

DOI:10.1080/00207178808906235

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Perturbation theory for output feedback eigenstructure assignment is considered. The analysis is based on general conditions for eigenstructure assignment, together with the well-known perturbation theory for the pseudo-inverse of a matrix. This enables us to present a variety of sensitivity analyses for this problem and to indicate some precautions when choosing eigenvectors in the pole assignment problem.

ISSN:0020-7179    

DOI:10.1080/00207178808906236

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This paper reports on the application of adaptive control techniques to the control of real-life biotechnological processes. The problem of regulation of the substrate concentration in the effluent of a multistage fermentation plant is considered in view of recent adaptive control concepts. The direct use of the process non-linear dynamics together with the on-line estimation of key process parameters gives rise to a robust (as BIBO stability analysis suggests) and efficient (as simulation and experimental results indicate) control scheme.

ISSN:0020-7179    

DOI:10.1080/00207178808906237

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A technique for designing moving-average precompensators that give the minimization of a tracking performance cost function while tracking either deterministic or stochastic reference inputs is presented. For deterministic reference inputs, the cost function is an infinite-time horizon quadratic sum of the dynamically weighted tracking error and dynamically weighted control input. For stochastic reference inputs, the sum of the variances of the dynamically weighted tracking error and dynamically weighted control input is minimized. The two types of cost function are shown to be equivalent and the same design technique is used for both. The precompensator is intended to be designed for use in cascade with a control system which has already been designed, possibly without regard to tracking. The minimization of the cost function is enhanced by increasing the number of terms in the precompensator above the minimum necessary to keep the cost finite. A simulation example is presented showing how performance improvements over pole-placement and error transfer function zero-placement controllers may be achieved.

ISSN:0020-7179    

DOI:10.1080/00207178808906238

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A closed-loop observer that can identify states and inputs simultaneously is developed for linear time-invariant systems with unknown inputs. The necessary and sufficient conditions for the existence of the observer are derived and proved. Parameter identification of a system with a few unknown or time-varying parameters is investigated by applying the observer technique developed in this paper. Potential usage in machine monitoring (machine diagnostics) appears promising.

ISSN:0020-7179    

DOI:10.1080/00207178808906239

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A methodology for the identification of multivariable processes is developed that can achieve a higher level of controllability by increasing one or more time delays between the inputs and outputs. By examining the delays in the numerator and denominator of the inverse of the process transfer function matrix, a procedure is given for the identification of the delays which should be increased, and by how much these delays should be increased, in order to yield the best performance. A simple heat recovery network provides a practical example of the application of this technique. An enhanced multidelay compensator, designed on the basis of the process model with increased delays, yields a consistently better closed loop response than existing compensators.

ISSN:0020-7179    

DOI:10.1080/00207178808906240

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor