Robust Design of Parallel Feedforward Compensators for a Class of Uncertain Non-minimum Phase MIMO Linear Systems

摘要

A parallel feedforward compensator V is a dynamical systems, attached to the given plant P in parallel. It is usually devised so that their parallel interconnection P + V possesses some desired properties that cannot be achieved via feedback control, e.g., passivity and the stability of zero dynamics. In this paper, we consider an uncertain MIMO linear plant P that have the vector relative degree {1, horizontal ellipsis , 1}. In particular, we do not restrict P to be of minimum phase and thus, it can be of non-minimum phase. For such P, we design V so that P + V is of minimum phase while the associated vector relative degree remains unchanged. In other words, the design allows us to robustly stabilize the zero dynamics of the system. The proposed design is based on an output feedback controller that stabilizes an auxiliary system, derived from the original plant P. The design is also applicable to the robust and adaptive stabilization problem of uncertain systems by output feedback. And in this context, we propose a robust output feedback controller for P, based on the designed V. Some examples, including F-16 aircraft, are provided to demonstrate the effectiveness of the proposed results.