Nonlinear position-flux zero-bias control for AMB system

This paper reports on a novel nonlinear controller for a single one-degree-of-freedom (1-DOF) Active Magnetic Bearing (AMB) system. The nonlinear feedback tools such as Lyapunov based techniques, control Lyapunov functions (CLFs), and feedback passivation control are developed. The control objective is to globally stabilize the mass position of an AMB with flux feedback. The flux-based control model for an AMB system is derived due to voltage switching strategy with voltage saturation. This strategy enables the flux control under a zero-bias operation. The proposed nonlinear CLF with a zero-bias can achieve a dynamic performance superior to that of a linear controller with the zero-bias or with the classical bias operations.