摘要:

The dynamic behaviour of a multivariable industrial system is rarely, if ever, completely known, owing to parameter uncertainties, measurement inaccuracies and other fluctuations. In some cases, the dynamic behaviour may be slowly time-varying. The design of constant precompensators or low-order dynamic compensators through a one-shot procedure to achieve exact decoupling of such systems is neither realistic nor practical. In the paper an adaptive decoupling algorithm is proposed for controller design, by specifying the closed-loop behaviour of the system in the form of a reference model, so that the controller parameters can be estimated online as the process develops. The approach uses the deterministic autoregressive moving average (DARMA) model for system representation. The performance of the algorithm is assessed using both dynamic and steady-state decoupling criteria. Simulation results demonstrate the ability of the algorithm to adapt the controller parameters to changes in the system parameters. Therefore, the algorithm will be more attractive for decoupling either unknown or slowly time-varying systems than the one shot technique of designing constant precompensators or low-order dynamic compensators to achieve exact decoupling.

DOI:10.1049/ip-d.1986.0042

出版商:IEE    

年代:1986

数据来源: IET

摘要:

The problem of representing a distributed system by a finite-order model is considered. It is shown that, by the application of the Shannon sampling theorem to spatial distributions, it is possible to define the order of the lumped model which is required. Results obtained in a practical application are presented. These results are consistent with the criterion based on the sampling theorem.

DOI:10.1049/ip-d.1986.0043

出版商:IEE    

年代:1986

数据来源: IET

摘要:

The problem of output feedback control design for discrete systems with fast and slow modes is considered. It is shown that, when the effect of the slow mode on the fast mode is linearly related to the slow output vector, the control design can be implemented in two stages by using separate gain matrices. The new output feedback design yields first-order perturbations in the behaviour of the discrete system. A ninth-order boiler model is used to illustrate the design procedure.

DOI:10.1049/ip-d.1986.0044

出版商:IEE    

年代:1986

数据来源: IET

摘要:

A representation for deterministic disturbances which is consistent with the usual representation for stochastic disturbances is given. Using the internal-model principle, a rearrangement of the estimation model which prefilters the input data is proposed. For the case of unknown deterministic disturbances, the prefilter parameters are adjusted adaptively. The proposed estimation model results in a parameter vector that does not contain the critical poles of the controller. Hence the risks of the controller having poles in the unstable region during the transient period are greatly reduced.

DOI:10.1049/ip-d.1986.0045

出版商:IEE    

年代:1986

数据来源: IET

摘要:

The paper describes a technique in self-tuning controller design in which tradeoffs can be made online between the control effort and regulation without affecting servoperformance of closed-loop systems. This flexibility cannot be achieved by modifying the reference model, pole positions or design variables in detuned minimum variance controllers. An example is given to illustrate the proposed methodology.

DOI:10.1049/ip-d.1986.0046

出版商:IEE    

年代:1986

数据来源: IET

摘要:

A novel method of linear system simplification is presented based on a modified factor division approach. It is seen to be more flexible than most model reduction methods in that families of reduced models may be easily generated by varying a single parameter in the modified transfer function denominator. It also guarantees stable reduced models of stable systems and preserves initial time moments and Markov parameters of the system. An example illustrates its application.

DOI:10.1049/ip-d.1986.0047

出版商:IEE    

年代:1986

数据来源: IET

摘要:

Sufficient conditions for global relative controllability of nonlinear systems with time-varying multiple delays in control and implicit derivatives are derived. The special case, when the delays are constant, is also considered and an example is provided. The results are obtained using the measure of noncompactness of a set and Darbo's fixed-point principle.

DOI:10.1049/ip-d.1986.0048

出版商:IEE    

年代:1986

数据来源: IET

摘要:

An adaptive algorithm is presented to incorporate pole/zero assignment as a principle design criterion. As this algorithm does not require solving a diophantine equation at each sampling step, it possesses much computational advantage over the existing approaches of an adaptive pole-assignment control algorithm. This computational advantage is very important for the adaptive control system to the actual application. The internal stability requirement is achieved so that this algorithm can easily handle any minimum- or nonminimum-phase system. The desired zero assignment of the sensitivity function can make high-order reference signal tracking possible. Several simulations are given to illustrate that our approach is suitable for application and easy to implement.

DOI:10.1049/ip-d.1986.0049

出版商:IEE    

年代:1986

数据来源: IET

摘要:

The simplest autonomous electronic circuit which can become chaotic was proposed recently by Chua. The objective of this paper is to describe a wide variety of bifurcation and chaotic phenomena observed experimentally from this circuit.

DOI:10.1049/ip-d.1986.0050

出版商:IEE    

年代:1986

数据来源: IET

摘要:

Comments are offered on a recent paper by A.T. Bada. It is shown that the responses of a predictor control system may be improved simply and systematically by the technique of deliberate mismatch of the plant model. This example supports the view that O.J.M. Smith's method, carefully extended, offers better performance than suggested in the paper.

DOI:10.1049/ip-d.1986.0051

出版商:IEE    

年代:1986

数据来源: IET