An approximate I/O linearization via nonlinear H/sup /spl infin// model matching

A nonlinear model matching problem is formulated as an output feedback nonlinear H/sup /spl infin// control problem. The model matching formulation can be employed to achieve approximate I/O linearization which is an alternative to the Lie-derivative type feedback I/O linearization. The H/sup /spl infin// approximate I/O linearization involves no zero dynamics, assumes no exact cancellations, yet allows the use of output feedback.