Controllability properties and prediction‐free control of linear systems with incommensurate delays

For linear delay systems with incommensurate (lumped) delays necessary and sufficient conditions for the freeness of the system over the ring of entire functions in are given. In contrast to the commensurate case the ring does not have the Bezout property. Therefore, additional criteria are needed involving also special properties of pure delay systems. Based on these results a prediction-free flatness-based control is designed for a system of two vibrating strings with a point mass and single boundary input. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)