MODELLING OF A PLANAR ACTIVE MAGNETIC GUIDANCE SYSTEM INCLUDING HYSTERESIS EFFECTS

Modern ultra-precision techniques require a positioning uncertainty below the 10 nm range with strokes of more than 200 mm in the x-y-plane. More precise knowledge and modelling of nonlinearities and disturbing influences are necessary to compensate these effects by means of suitable control algorithms. A nonlinear state-space model of an active planar magnetic guidance system is proposed. To describe magnetic hysteresis effects appropriately, the Jiles-Atherton method is applied. The nonlinear model presented in this paper can be used to design a model-based controller for plant linearisation and hysteresis compensation.