Further Results on Active Magnetic Bearing Control with Input Saturation
  We study the low-bias stabilization of active magnetic bearings (AMBs) subject to voltage saturation based on a recently proposed model for the AMB switching mode of operation. Using a forwarding-like approach, we construct a stabilizing controller of arbitrarily small amplitude and a control-Lyapunov function for the AMB dynamics. We illustrate our construction using a numerical example. 
Frederic Mazenc, Marcio S. de Queiroz, Michael Malisoff, Feng Gao