Systems with Parametric Uncertainty Described by Varying Intervals

In this paper the problem of computing stability margin of uncertain continuous-time linear time invariant systems with coefficients described by fuzzy numbers is solved. All the coefficients are considered as variable intervals parametrized by the degree of confidence in the corresponding model. The lower the confidence level is the larger interval the coefficient can vary in. In the paper the common confidence level for all the coefficient is considered. The result is derived based on parametrization of lower and upper bounds of the intervals and using the Hurwitz criterion.

Keywords:

Robust stability , parametric uncertainty , fuzzy number