Design and implementation of a 2-DOF PID compensation for magnetic levitation systems

This paper employs a 2-DOF (degree of freedom) PID controller for compensating a physical magnetic levitation system. It is shown that because of having a feedforward gain in the proposed 2-DOF PID control, the transient performance of the compensated system can be changed in a desired manner unlike the conventional 1-DOF PID control. It is also shown that for a choice of PID parameters, although the theoretical loop robustness is the same for both the compensated systems, in real-time, 2-DOF PID control may provide superior robustness if a suitable choice of the feedforward parameter is made. The results are verified through simulations and experiments. •A novel 2-DOF PID controller design is proposed and applied to a physical magnetic levitation (MAGLEV) system.•The performance and robustness of the 2-DOF PID controller are examined and compared with 1-DOF based PID controller.•The superiority of the 2-DOF design over 1-DOF one is verified through simulations and experiments.