Parametric Uncertainty Modeling using LFTs

In this paper a general approach for modelling structured real-valued parametric perturbations is presented. It is based on a decomposition of perturbations into linear fractional transformations (LFTs), and is applicable to rational multi-dimensional (ND) polynomial perturbations of entries in state-space models. Model reduction is used to reduce the size of the uncertainty structure. The procedure will be applied for the uncertainty modelling of an aircraft model depending on altitude and velocity (flight envelope).