Velocity Control of Permanent Magnet Stepper Motor Using Nonsingular Terminal Sliding Mode Control

Abstract

Permanent Magnet Stepper Motor is a device that can convert electrical pulse signals into angular displacement. It has the advantage of high accuracy, low cost and power density. Due to the parameters and model of PM stepper motor are affected by its application environment, it is difficult to be controlled accurately. Since we used Nonsingular Terminal Sliding Mode (NTSM) control method at stationary axis ( alpha , beta ) of Permanent Magnet Stepper Motor for improving the velocity and currents tracking performance in this thesis. Compare to conventional Sliding Mode control method, the state which was implemented by the proposed method can arrive the manifold in finite time. The closed-loop stability of the NTSM has been proven byLyapunov function in this thesis. With the proposed method, we can improve the reference velocity tracking performance and reduce chattering. From simulation results, we observed that the reference tracking error converges into equilibria.