Reduced order controller design for disturbance decoupling problems

Over the past 50 years, many techniques for model based control have been developed. These techniques are typically applied to small-scale systems with up to ~10 states. From industry there is an increasing interest in applying model based control techniques to large-scale models that contain over 1;000 states. These models typically show up for systems that are described by partial differential equations, which are spatially discretized using finite elements or finite volume methods.

Due to computational limitations, it is in practice required to determine a controller that contains at most ~100 states. Therefore the problem of designing of a reduced order controller for a full order system is of great interest.