Active Disturbance Rejection Control of a Magnetic Screw Motor for High Tracking Performance

A magnetic screw motor integrated by a magnetic screw and a permanent magnet synchronous motor offers high thrust density without friction and loss. However, its internal structure is complicated, resulting in difficulty to control its linear displacement to track the given signal in time and even getting out of control due to interference. In this article, to improve the tracking performance and anti-interference performance of the system, an active disturbance rejection controller (ADRC) is adopted to improve the current loop and makes up for nonlinear regional control in the closed-loop control system. To ensure the stability of the proposed scheme in the entire operation range, the design and the stability analysis are carried out in the continuous-time domain. The novel control algorithm enhances the flexibility of the magnetic screw motor by optimizing the nonlinear function in ADRC. In addition, to highlight the high-performance control of the ADRC for the magnetic screw motor, sliding mode control and PI control are added to compare with it. Finally, the reciprocating motion control is added to show the diversity of the functions of the magnetic screw motor, which verifies the effectiveness and feasibility of the control algorithm.