Velocity ripple minimization in permanent magnet stepper motor using current error based iterative learning control

In this paper, iterative learning control (ILC) with field oriented control is proposed to reject periodic velocity ripple which are casually detent torque and other various sources in permanent magnet stepper motor (PMSM). Single-input single-output (SISO) system structure with field-oriented control (FOC) is proposed to be applied to ILC. To make the error convergence fast, current error based ILC using plant inversion method is designed. The condition that error converges to zero is derived. Simulation results show that the velocity ripple is cut in by using ILC.