A Short-Stroke Permanent Magnet Aerospace Actuator with High Force-to-Mass Ratio

High energy density rare earth permanent magnets have catalysed substantial improvements in the performance of linear actuators. The design of such a device using the 2D finite element method coupled to a particle swarm optimisation is described. A particular attribute of the design is that the pole shape has been optimised to ensure restoring magnetic forces act on the effector at zero current. A mathematical model is developed to study the dynamic performance of the device. A prototype was constructed from cobalt iron laminates and high energy product permanent magnets. Electrical winding tests and force measurements for the prototype are presented and compared with modelled values