Feedback linearization via state transformation using estimated states

This paper deals with the exact feedback linearization of nonlinear plants using estimated states. Under appropriate hypotheses, exact linearization c an be achieved through transformation of states and feedback. We assume tha t the states cannot be measured so that a nonlinear observer, with exponent ial convergence, is included in the loop. We establish sufficient condition s to guarantee that the overall system trajectories asymptotically converge to those obtained with feedback linearization utilizing the true states. W e apply our results to control an electrical drive using a permanent-magnet synchronous motor without mechanical and optical sensors. The behaviour of our control scheme is illustrated by simulations.