Modeling uncertainty of flexible structures for controller design

An approach is presented for modeling with least additive uncertainty from a priori information of a plant. A feasible set of systems is defined as the set of all systems governed by a class of differential equation with certain norm bounds of unknown input and output operators as well as partially known eigenparameters. Then an unstructured uncertainty class including the feasible set is characterized with least magnitude of additive perturbation in frequency domain. An example of finite dimensional compensator design is demonstrated to illustrate the usefulness of the presented approach