Abstract—A magnetic levitation ball (MLB) is required to operate over large variations in the air gap. Specifically, it may be difficult to design a linear controller that can provide satisfactory performance, stability and disturbance rejection over a wide range of operating points. Conventional controllers with the linearisation of a nonlinear system exhibit a low-efficiency control performance. To simplify a complex control system, in this paper, we analyse the robustness and stability of disturbance for a magnetic levitation system using Jacobian linearisation from the equilibrium point, by adding one integrator in an open-loop model and servo control system design with a state observer. The experimental results show that this method can be effectively controlled by dynamic response criteria of the control system.