Experimental Study on Steel Plate Shape in Magnetic Levitation System Using Both Electromagnet and Permanent Magnet

Abstract

  In the process of manufacturing thin steel plates, the deterioration in the surface quality of steel plates is a serious problem caused by contact between the plates and rollers. To solve this problem, our research group considered non-contact suspension by using electromagnetic levitation. When the thickness of a steel plate is too thin, levitation control becomes difficult because the deflection of the steel plate leads to complex vibration. Therefore, we previously proposed adding permanent magnets to suppress the deflection. The patterns in which the magnets were arranged were too large in number to find the optimum arrangement experimentally, so we applied a genetic algorithm to search for the optimum arrangement. In the previous study, optimization was carried out to suppress the average and maximum deflection of steel plates equally, and we confirmed that the levitation performance was improved by applying an optimized arrangement of permanent magnets. In this paper, we optimized the arrangement by changing the weight factor of the average and maximum deflection with the genetic algorithm and performed a levitation experiment by using this optimized arrangement. From the results, we found that this change had a positive effect on levitation performance.