Adaptive nonlinear control of rigid robots driven by current-fed induction motors

In this paper, we consider the problem of controlling a rigid robot driven by induction motors operating in the current-command mode to follow a desired trajectory. We propose an adaptive nonlinear controller which utilizes measurements of link positions and velocities as well as stator currents of induction motors. The rotor flux is estimated through a closed-loop observer. The controller compensates for parametric uncertainty associated with the resistance of the rotor windings and ensures asymptotical tracking to the desired trajectory. Simulations are presented to illustrate the performance of this controller.