Research on robust two-degree-of-freedom for high stiffness electromagnetic suspension unit

For the electromagnetic suspension unit, a robust two-degree-of-freedom (2-DOF) control strategy based on combining feedforward control and H_infin control is investigated in this paper. The control scheme solves the conflict between accurate command tracking performance and disturbance rejection of the system. The feedforward controller is designed to ensure that the system implements accurate tracking performance. While H_infin controller can overcome the influences of the uncertainties of parameter perturbations and external load disturbances, achieve stability and robustness. The simulation results show that the control scheme not only can ensure system strong robustness to parameter uncertainty and load disturbances, but also improve accurate tracking performance.