Bending magnetic levitation control for thin steel plate (experimental consideration using sliding mode control)

In conveyance manufacturing process of thin steel plate, since the plate always in contact with the roller, there is problem that the surface quality deteriorates over time. To solve this problem, electromagnetic levitation technologies have been studied. However, when a flexible thin steel plate with a thickness of less than 0.3 mm is to be levitated, levitation control becomes difficult because the thin plate´s flexure increased. We propose a levitation of an ultrathin steel plate that bent to an extent that does not induce plastic deformation. It has been confirmed that vibrations are suppressed and levitation performance improved. In this study, in order to examine the levitation stability and to compare the levitation performance, bending levitation experiments were carried out on the basis of the optimal control and sliding mode control theory using thin steel plate with a thickness of 0.27 mm.