Nonlinear adaptive sliding mode control of a rigid rotor via contactless active bearing

Three-pole Active Magnetic Bearing AMB is a cost-effective method for implementing the principle of magnetic levitation in rotary devices as a bearing support. The nonlinear and unstable nature of three-pole AMB is a challenge for controller design. This study investigates the nonlinear characteristics of three-pole AMB and the design of a sliding mode controller to control AMB dynamics. The system is standardised into extended controllable canonical form, and the controller is designed. The inherent chattering of the sliding mode controller is also addressed with a solution of sliding gain adaptation. The simulation of the controller and the AMB analyses the performance of a system using the proposed controller.