State-feedback decoupling control of 5-DOF magnetic bearings based on α-order inverse system

Abstract In the face of magnetic bearing rotor system multivariable, nonlinear, strong coupling control problems, a novel control decoupling method based on inverse system state feedback decoupling theory for the five degree of freedom of active magnetic bearing is presented. It solved the problem of ignoring the limitation of control parameters in conventional control methods. In this paper, the rigid body dynamics model of magnetic suspension rotor is established and the linearization is carried out. In this study, a decoupling pseudo-linear system is constituted by cascading the α-order inverse system based on the state-feedback with the original system. Moreover, in order to improve the robustness of the whole system and reject the influence of the un-modeled dynamics, the internal model controller is designed to synthesize the whole system. Both simulations and experiments demonstrate the effectiveness in decoupling of magnetically-levitated rotor system, and the disturbance rejection of proposed control scheme can be enhanced compared with un-decoupled control schemes.