Low-dimensional functional observer design for linear systems via observer reduction approach

This paper proposes a design method for low-dimensional linear functional observers based on a model reduction approach. In contrast to existing methods for designing approximate observers, this method can guarantee not only stability preservation but also an a priori L₂-error bound for the observer approximation. Moreover, owing to the fact that this method can be applied to any Luenberger-type functional observers, the method is compatible with the standard feedback gain determination methods, such as pole placement techniques. The efficiency of the proposed method is shown through a numerical example for electric power network systems.