Integrated electromagnetic levitation and guidance system for SwissMetro project

Electromagnetic levitated and guided systems are commonly used in the field of people transport vehicles, tool machines, frictionless bearings and conveyor systems. In the case of low speed people transport vehicles, the electromagnetic levitation offers the advantage of a very silent motion and of a reduced maintenance of the rail. In the world there are actually two working low speed systems: the japanese HSST ( [1], [2] ) and the english BAMS ( Birmigham Airport MagLev System [3] ). In both these magnetically levitated trains the guidance force needed to keep the vehicles on the track is obtained with the levitation electromagnets, thanks to particular shapes of the rails and to a clever placement of the electromagnets with respect to the rails ( [4] ). This paper shows a simple magnetic model for the study of the levitation and guidance forces produced by an electromagnet coupled with an iron rail. The rail and electromagnet shapes taken into consideration in this paper can better refer to the japanese HSST than to the english BAMS. This paper will also deals with the study of the guidance force in the case of a vertical position control. The study shows that the guidance force can be stronger than in an open loop study.