Zero phase 2-DOF H infinity robust tracking control for permanent magnet linear synchronous motor

For the direct-drive servo system of permanent magnet linear synchronous motor (PMLSM), a two-degrees of freedom (2-DOF) robust tracking control strategy based on combining zero phase error tracking control (ZPETC) with H infinity robust control is proposed. The control scheme solves the conflict between fast tracking performance and interference rejection of the linear serve system. The zero phase error tracking controller is designed to ensure that the system has fast tracking performance and implements exactly tracking, especially when it is used for contour control, better effect is obtained. It can effectively improve positioning accuracy and fast tracking performance. While the H infinity robust controller can overcome the influences of the uncertainties of parameters perturbation and external load disturbances, achieve the stability and robustness of the system. The simulation results show that the control scheme not only can enhance fast tracking performance, but also has a strong robustness to parametric variations and resistance disturbances.