Robust control using linear quadratic method in hybrid-electromagnetic suspension system

Hybrid-electromagnetic suspension (EMS) system is type that vehicle levitates from guide-way. An advantage of this system is no energy consumption at nominal operating point which is maintains levitation using attraction force by permanent magnetic only. The EMS system is inherently unstable. It means active control needs to be incorporated for stable levitation. And it needs control method which is satisfied stability and robustness when disturbance is existed. This paper presents robust control using linear quadratic (LQ) method in hybrid-EMS system. We simulate dynamic characteristics using pole replacement method and LQ method. The proposed method is better dynamic response by computer simulation.