摘要:

We consider some of the issues of implementing the prediction and control algorithms of the companion paper (Heath and Weltstead 1994). The algorithms are suitable for setting in self-tuning mode by combining them with recursive parameter estimation algorithms. The problems of set-point tracking and offset handling are also considered. It is shown that if the two-dimensional process can be modelled as incremental, then the solution is particularly staightforward. Throughout, the results are illustrated by simulations.

ISSN:0020-7179    

DOI:10.1080/00207179508921542

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A multiple-input/multiple-output graph reversal technique is developed and applied to the design of parallel control (and signal processing) architectures using systolic arrays as a design example. Using this method, it is possible to develop novel architectures with, in feedback control applications, the essential property of short latency. Further, it can also be used to expand existing architectures at both array and cell levels. A systematic method for verifying the transfer function (or transfer-function matrix in the multivariable case) which is easy to use and requires no manual iteration is developed. In developing this method, the well known ABCD transmission matrix description of an analogue network is extended to the digital domain. Some areas for short to medium term further research/development are briefly noted.

ISSN:0020-7179    

DOI:10.1080/00207179508921543

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A non-stochastic state-space identification algorithm for linear time-invariant systems is modified for use with periodic linear systems. Like its predecessor, the modified algorithm forms block Hankel matrices from input-output data and uses the singular value decomposition of these Hankel matrices to compute state vector sequences. The state vector sequences are then used to compute system matrices associated with the periodic linear system by solving an (overdetermined) linear system. The modifications to the original algorithm are as follows. First, the periodic system of periodpis viewed aspseparate time-invariant period-mapped systems. This technique allows the structure of a periodic Hankel matrix to be deduced, which in turn allows a state vector sub-sequence for the periodic system to be computed. When a complete state vector sequence is computed, it is used directly to construct the periodic state-space models. Second, similarities in the structure of each of the periodic Hankel matrices associated with the p time-invariant period-mapped systems is exploited in such a way that not only reduces the amount of computation necessary, but also improves the accuracy of the computation of the system matrices.

ISSN:0020-7179    

DOI:10.1080/00207179508921544

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We consider adaptive control via state feedback for a class of feedback linearizable discrete-time systems. To parallel the development in adaptive nonlinear continuous-time control, we employ a systematic procedure to design the controllers and the update laws for the so-called parametric-strict-feedback form and the parametric-pure-feedback form. The geometric conditions that characterize this class of systems are given. Depending on the growth conditions of the nonlinearities, global boundedness and convergence are achieved with various update laws. We also develop adaptive indirect schemes with an observer-based identifier for the parametric-strict-feedback form. As a result, the drawback of overparametrization in direct schemes can be removed.

ISSN:0020-7179    

DOI:10.1080/00207179508921545

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The design of robust digital controllers for systems with time delay is investigated. A particular class of digital controller is considered, namely those for which the closed-loop poles include the poles of the system to be controlled. Robust design with respect to time delay variations requires the introduction of additional closed-loop poles and/or reduction of the gain of the feedback path at high frequencies (near 0-5fs, wherefsis sampling frequency). Relationships with other robustification procedures are examined.

ISSN:0020-7179    

DOI:10.1080/00207179508921546

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A series of piecewise multiple general orthogonal polynomials (PMGOPs) is introduced and applied to the parameter identication problem for a class of continuous nonlinear systems. After introducing PMGOPs and discussing their main properties, an effective procedure for the parameter identification of a large class of continuous systems, called parameter separable systems, is proposed. Some relevant algorithms are presented. The procedure given in the paper has the following advantages compared with other methods: the identification algorithm (IA) obtained is computationally fast and accurate; the IA can be implemented in a recursive fashion; the IA is effective for a small number of data points; the IA does not requirea prioriknowledge of the estimated parameters; the IA is tolerant to choices of expanding orders when PMGOPs are applied. Some numerical examples, together with an experimental example taken from a biochemical fermentation process, are given for illustrative purposes.

ISSN:0020-7179    

DOI:10.1080/00207179508921547

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In this paper, the first of two, we examine the problem of modal control of linear, time-invariant, multivariable descriptor systems. In particular, for systems satisfying a certain inequality we will give necessary and sufficient conditions for the existence of an output feedback matrix (possibly complex) which exactly assigns an arbitrary set ofr(the number of independent semi-state variables of the system) distinct complex numbers to a generalized eigenspectrum of the closed loop system while ensuring that the resulting system has a unique smooth solution for each admissible initial condition. Furthermore, it is shown that if the set of proposed poles contains only real elements, the assignment can be carried out using real feedback. Next, we present conditions that are necessary and sufficient for pole assignability by real feedback of a self-conjugate set of complex numbers provided that the system satisfies a further inequality.

ISSN:0020-7179    

DOI:10.1080/00207179508921548

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We conclude our investigation (started in Part 1: Goodwin and Fletcher ) of the problem of pole assignment by real output feedback in descriptor systems. Sufficient conditions are given for the existence of a real feedback matrix which exactly assigns an almost arbitrary set ofr(the number of semi-state variables of the system) distinct numbers to the closed-loop generalized eigenspectrum of the system. It is further shown that where exact assignment may not be possible we can at least approximately assign the set. This agrees with work of other authors (see, for example, Ailon 1991). The sufficient conditions combine with results from Part 1 to give criteria for pole assignment. Furthermore, the inductive nature of the proof in this paper (and also in Part 1) gives rise to an algorithm for calculating the desired feedback when it exists.

ISSN:0020-7179    

DOI:10.1080/00207179508921549

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The paper considers a problem of absolute stability for a nonlinear uncertain system with structured uncertainty. AnS-procedure for nonlinear systems is established and, using this, the paper shows that the absolute stability problem is equivalent to an absolute stability problem for a nonlinear uncertain system with unstructured uncertainty. The paper also introduces a new notion of structured dissipativeness for nonlinear systems. This notion extends the standard notion of dissipativeness in that it allows for multiple supply functions. The paper shows that a nonlinear uncertain system containing structured uncertainties will be absolutely stable if and only if a corresponding structured dissipativeness condition is satisfied. It is also shown that structured dissipativeness is equivalent to the standard notion of dissipativeness with a parameter dependent supply function.

ISSN:0020-7179    

DOI:10.1080/00207179508921550

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A novel fault detection/diagnosis technique for linear dynamic systems is proposed. In comparison with existing schemes, the proposed method achieves fault detection/diagnosis using neither observer residuals nor parameter estimation errors; instead, it relies on the estimation of the underlying modal parameters of the system. The estimated modal parameters are compared with pre-calculated characteristic patterns of the system, which are represented as a set of root loci in terms of the physical system parameters. The modal parameter estimation is carried out using a numerically robust least-squares algorithm based on singular value decomposition. A pattern recognition technique employing linear multiprototype distance functions is used to classify the faults according to the variations of physical parameters. The proposed method has been applied to a simulated DC servo system where faults are introduced as abrupt changes in physical system parameters. It is shown that the proposed scheme is capable of diagnosing most of changes in physical system parameters.

ISSN:0020-7179    

DOI:10.1080/00207179508921551

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor