Robustified H2-control of a system with large state dimension

We consider the design of an output feedback controller for a large scale system like the linearized Navier-Stokes equation. We design an observer-based controller for a reduced system that achieves a compromise between concurring performance and robustness specifications. This controller is then pulled back to the large scale system such that closed-loop stability is preserved, and such that the trade-off between the H2- and H∞-criteria achieved in reduced space is preserved. The procedure is tested on a simulated fluid flow study.