Description And Analysis Of Interval Systems

Control of real industrial processes is almost always burden with an uncertainty. The reasons of that unfavorable fact are mainly an imprecise modelling and measuring or an influence of some external conditions. A convenient tool for dealing with such class of issues represents the application of models with parametric uncertainty. The mathematical model is then supposed to contain parameters which are not precisely known, but the values thereof lie within given intervals. If individual uncertain coefficients (in polynomial, in transfer function etc.) are mutually independent, the uncertainty has a simple interval structure. This contribution offers several possibilities of utilization of interval uncertainty for systems description and presents the tools for robust stability analysis, emphasizing advantages and limitations connected with the use of this simple structure, even for more complicated problems.