Design of [H.sub.[infinity]] position tracking controllers for current-fed induction motors used in articulated mechanical loads

This paper describes a systematic procedure to design [H.sub.[infinity]] position and flux-norm tracking controllers for current-fed induction motors. The designed controllers achieve convergence to zero of both position and flux-norm tracking errors while ensuring robustness with respect to unknown load torque disturbances. The proposed procedure offers the possibility of a simple development of the controllers' design; in particular, it does not require a numerical solution of the Riccati matrix equation. A case study has been set up which considers the application of the proposed control scheme to a two-link robot manipulator system actuated by two induction motors. Numerical simulation results confirm the validity, of the proposed design methodology, even in the presence of rotor resistance uncertainty.