A note on the design of the robust regulator for non-minimum phase linear systems

This paper deals with the design of robust error feedback regulators for uncertain linear systems. The aim is to identify constructive design procedures able to systematically deal with possible unstable zero dynamics. To this end we specialize the results proposed by Marconi and Isidori (2003) in a general nonlinear setting to linear systems and we present two constructive results in the frequency domain. The design of a robust regulator for the linearized model of an inverted pendulum on a cart is finally presented to illustrate the effectiveness of the result.