A model reduction scheme with preserved optimal performance

This paper addresses a problem in control relevant model reduction. More specifically, a model reduction scheme is proposed that preserves the disturbance decoupling property of the to-be-reduced plant. It is shown that optimal feedback laws designed for the reduced system will actually be optimal for the non-reduced system. Moreover, a characterization is given for the minimal reduction order for which this property can be established. This can be extended to the design of observers for complex systems. The results are illustrated by a simulation example.