Magnetic Propulsion Force Calculation of a 2-DoF Large Stroke Actuator for High-Precision Magnetic Levitation System

The design of high-precision magnetic levitation positioning systems requires fast electromagnetic models. Since three-dimensional finite element method (3D-FEM) is very time-consuming, in order to calculate magnetic forces, an interesting alternative is to determine the forces semi-analytically due to the high accuracy with a short calculation time. In this paper, a new compact semi-analytical equation for determining the magnetic propulsion forces of a new ironless two degrees of freedom (2-DoF) actuator for a high-precision magnetic levitation system is presented. The derived equation is based on the magnetic scalar potential and the Lorentz force law. An important result is that this new expression takes also the position dependence of the propulsion forces over the whole planar stroke into account. The calculated propulsion forces from the derived equations and the verification by 3D-FEM (Maxwell 3D) are presented in this paper as well.