Permanent Magnet Stepper Motor Control

Background :

The permanent magnet stepper motor has traditionally been used for open loop discrete position control. Internal torque mulitplication allows it to be used in applications needing high torque source. Continuous movement of the stepper motor can be achieved by designing a commutation strategy that distributes the control responsibility between the two phases depending on the position of the rotor.

The motor has a very high torque/inertia ratio. The absence of brushes is an added advantage.

Research Work:

The following position controllers were successfully implemented on a two-phase permanent magnet stepper motor:

  • Exact Model Knowledge Position Tracking Control
    • Feedforward, full-state feedback control
    • Output feedback control
  • Adaptive Position Tracking Control
    • Feedforward, full-state feedback control with on-line parameter estimation.
    • Partial-state feedback control with on-line parameter estimation.
    • Full-state feedback control with reduced overparameterization.
  • Robust Position Tracking Control
  • Feedforward control with high gain feedback to compensate for parametric uncertainty.

The following velocity controller was successfully implemented on a two-phase permanent magnet stepper motor:

E-Mail CRB Home Page