H^∞ Control of Magnetic Levitation System with Flexible Guideway and Flexible Slider

This study is concerned with a spillover problem in the magnetic levitation system. First, we show the typical spillover phenomena caused by the interaction between the control system and structure system of the magnetic levitation system. Next, applying theH^∞control theory as a mixed sensitivity problem to a magnetic levitation system, we design a control system for a system without spillover and show the experimental data obtained when using the H^∞controller. In this paper, the control performance of the mixed sensitivity problem is compared with the control performance of the robust stability problem through experiments. As a result, it has been clarified that the H^∞ controller as a mixed sensitivity problem is superior to that of a robust stability problem for disturbance attenuation. Next, we show the experimental data of more difficult magnetic levitation problems with a flexible guideway and a flexible slider. In experiments, we obtained good data of the magnetic levitation for such a system without spillover.