Control of Magnetic Bearings

In this chapter, we study various aspects of the motion planning and nonlinear feedback design for a rotating shaft actuated by active magnetic bearings. The shaft is here assumed to be rigid and balanced. The magnetic bearings are made up with pairs of electromagnets, one for each direction to be controlled, possibly completed by a passive thrust. Each electromagnet produces an attractive force, whose intensity depends on the coil current, which explains why they are used by pairs in order to produce forces with both signs.