Research on design and control of direct magnetic suspension permanent magnet linear motor

In order to eliminate the friction force of linear motor numerical control machine tool feed system, a new direct magnetic suspension permanent magnet linear synchronous motor(PMLSM) was putted forward in this paper. First, the motor was modeled and analyzed by finite element software, the results show that the motor can respectively generate the suspension force and thrust and the force could be controlled. The thrust and the suspension force can achieve the decoupling, and then, the motor servo control system could be divided into two independent subsystems. Presents two-degree-of-freedom robust control for suspensions subsystem. The results of simulation indicate that the system with this controller has a good performance for restraint disturbance as well as for track of input signal. For feed subsystem presents H_∞ robust control strategy. The results show that controller had excellent disturbance attenuation performance and model uncertainty attenuation performance. The system meets the requirement of robustness and rapidity for the friction-free feed of NC machine tools.