Study of magnetic levitation for a 0.18-mm-thick steel plate by adopting twisting-mode control

Magnetic levitation techniques [1]-[3] have been used in various industry areas. Recently, although adopting magnetic levitation techniques in a process line for very thin steel plates is expected to maintain the high quality of the plate surfaces, the realization has not been achieved. The reason is that the control for magnetic levitation is very difficult due to the magnetic saturation and the vibration of thin steel plate [4]. However, we had already established stable magnetic levitation, guidance and conveyance control for 1.6mm-thick steel plates without any contact. Fig.1 shows the magnetic levitation system for the thin steel plate that consists of four electromagnets, four gap sensors, two sideslip sensors, and LabVIEW-PXI (DSP with A/D and D/A converters).