Robust position sliding-mode control of a permanent-magnet motor using a load-torque observer

A robust position controller for a permanent-magnet synchronous motor is presented. The use of sliding mode control with a suitable choice of the commutation law gives to the system an insensitivity concerning parameter variations, supply voltage changes, and load perturbations. The measure of certain state variables like acceleration may pose some implementation problems. A load torque observer overcomes this effect. Theoretical studies and results show that the proposed control technique provides good performance for regulation and tracking applications