摘要:

This paper develops an algorithm which, given an input-output differential equation, produces under appropriate circumstances a parametrization of the observation space of the underlying state-space system. The paper extends previous results by the authors to a more general setting, so that state-space systems, in which the controls enter nonlinearly, can be accommodated and, most importantly, the paper deals with implicitly defined systems at both the input-output and state-space level. Fliess and Hasler have demonstrated the importance of implicit input-output models, which yield only local state-space descriptions. Various realizations are obtained, depending on the properties of the derived candidate observation space. Examples of the algorithm are described, with the aid of an implementation using the computer algebra system AXIOM.

ISSN:0020-7179    

DOI:10.1080/00207179508921576

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The problem of the control of multivariable systems in the presence of both modelling and disturbance uncertainties is considered. The technique described is not restricted to linear systems, nor to systems where the uncertainties satisfy matching conditions. Only bounds on the uncertainties are required. As examples of the technique, two practical problems are considered.

ISSN:0020-7179    

DOI:10.1080/00207179508921577

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The two-degrees-of-freedom Internal Model Control structure allows a good combination of set-point control and load disturbance rejection for processes with time delay. A design principle for improved disturbance control with this structure is presented. It provides a response to load disturbances that is independent of the dynamics of the disturbance. The controller is suitable for slow load disturbances, deteriorating the control performance of time delay compensation controllers like the Smith predictor and the Dahlin controller. An earlier design approach, proposed in order to improve the disturbance rejection characteristics of the Smith predictor, is briefly discussed. The new design principle is compared with a simplified design method related to the original Dahlin algorithm. The comparison is made for equal robust stability. The comparison shows to what extent taking into account the disturbance dynamics is worthwhile, when designing a controller.

ISSN:0020-7179    

DOI:10.1080/00207179508921578

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor