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-sin gle-output systems which have completely unstable (antistable) zero dy namics. The approach is similar in spirit to linear approaches for non minimum phase systems and involves the derivation of an input-output l inearizing controller for a suitably-defined nonlinear minimum phase a pproximation to the original system. The linearizing controller achiev es an approximately linear input-output response and internal stabilit y.