ABSTRACT
In this chapter, we explore the concept of flatness in the context of time-invariant linear multivariable systems, or, shortly, MIMO systems. As in the previous SISO case, the flatness property of the system is intimately related to the controllability of the system. They are, again, equivalent concepts. Thus, since controllability has been completely characterized, in the existing literature, for systems described in transfer matrix forms and also for systems placed in state space forms, we shall explore the characterization of flatness, and in particular that of the flat outputs, for both types of system representations.
