An output feedback tracking controller for systems diffeomorphic to the non-linear observer form

An output feedback tracking controller is proposed for single-input, single -output non-linear systems that are diffeomorphic to the non-linear observe r form. Difficulty in obtaining the output injection terms of the non-linea r observer form is solved by a numerical technique and the interpolation me thod using the radial basis function (RBF) network. The trained RBF network s approximate output injection terms in a compact interval and are utilized for building a non-linear observer. In constructing the output tracking co ntroller the backstepping control method is adopted based on the state esti mates.