ABSTRACT
This chapter develops a load position tracking controller for the electromechanical model of an induction motor driving a position-dependent load under the assumptions that load position, load velocity, and stator current measurements are available and that an exact model for the electromechanical system dynamics can be determined. Specifically, by utilizing the structure of the induction electromechanical system, we design nonlinear observers to estimate the rotor flux. Specifically, a general statement on the open-loop rotor flux observation error is prevented by the fact that the rotor flux observation error dynamics contain additional nonlinear control terms which facilitate the design of a singularity-free position tracking controller. A Lyapunov-like argument is used to prove that all of the signals in the actual electromechanical systems and the observer remain bounded during closed-loop operation. Furthermore, the controller ensures that the load position tracks the desired trajectory exponentially fast into some small ball.
