Special coordinate basis for order reduction of linear multivariable systems

A method of nested feedback loop decomposition of a given system is developed. It is based on a special coordinate basis which reveals the finite and infinite zero structure of the given system. This decomposition leads to a model order reduction procedure by which any arbitrary subset of the system invariant zeros could be retained in the model while the infinite zero structure of the model and the given system are one and the same. Thus, the method of model order reduction reduces the dynamic order via the zero structure of the given system