Improved Magnetic Levitation Via Online Disturbance Decoupling

Control of magnetic levitation systems suffer from coupled physics regardless of control. Feedback control is used to robustly reject disturbances, but is complicated by this coupling. Improved performance is possible by decoupling dynamic disturbance torque, an attractive solution provided by the physics-based control design methodology. Promising approaches include elimination of virtual-zero references, manipulated input decoupling, sensor replacement and disturbance input decoupling. This paper compares the performance of the physics-based control to control methods found in the literature typically including cascaded control topology and neglecting factors such as back-emf.