Design of the current controller for the permanent magnet spherical stepper motor

In view of improving control capability, a current controller of the permanent magnet spherical stepper motor was designed in this paper. Adaptive and switching control algorithms assured the rotor to drive mechanical loads following the continuous path motion and alleviating the tracking errors. Current-tracking PWM technology was applied in the controller. Simulation and experiment results show that the current controller can actualize the advanced algorithms by controlling the currents in the stator coils according to the desired current curves.