On the ${\mathcal{H}}_2$ norm and iterative model order reduction of linear switched systems

A new definition of the ${\mathcal{H}}_2$ norm for linear switched systems is introduced. It is based on appropriately defined time-domain kernels, or equivalently, on infinite controllability and observability Gramian matrices. Furthermore, an extension of the iterative rational Krylov algorithm to the class of linear switched systems is proposed.