A normal form approach to approximate input-output linearization for maximum phase nonlinear SISO systems

A control synthesis scheme is presented for nonlinear single-input-single-output systems which have completely unstable (antistable) zero dynamics. The approach is similar in spirit to linear approaches for nonminimum phase systems and involves the derivation of an input-output linearizing controller for a suitably-defined nonlinear minimum phase approximation to the original system. The linearizing controller achieves an approximately linear input-output response and internal stability.