Study on decoupling control of bearingless motorized spindle

Abstract

Bearingless motorized spindle is a kind of spindle structure that combines a bearingless motor with a motorized spindle. It has the advantages of a motorized spindle and a bearingless motor, which can further improve the speed of the machine tool spindle. However, its complex electromechanical structure and the coupling relationship between the subsystems make it difficult to control its operation process accurately. In this paper, the voltage control decoupling method is used to decouple the torque and suspension system of a bearingless motorized spindle with an independent inverse system, then control the systems. Finally, the control of decoupled bearingless motorized spindle is simulated. The results show that when the speed, rotor radial displacement, and rotor flux change respectively, they will not influence each other. The speed and radial displacement are unaffected after the sudden load is applied. It proves the effectiveness of the decoupling control method.