Geometry of efficient Electromagnetic Linear actuators for flapping wing MAVs

Abstract

A constraining factor in the development of flapping wing micro air vehicles (MAVs) is the power density and efficiency of actuators. Piezoelectric and rotary electromagnetic actuators have been shown to have functional power densities but can require mechanically complex transmissions to create flapping motion. Electromagnetic Linear actuators (ELAs) have unique characteristics, allowing them to be controlled and implemented similarly to muscles but demonstrated much lower efficiency. This study presents configurations of ELA consisting of multiple coils and magnets that have the potential to improve efficiency. The use of lightweight conductors in the form of copper clad aluminium (CCA) is explored as a method to improve power density. A numerical method of optimising the geometry and mass distribution of the magnetic and conductive material is presented. The results show the power consumption of these actuators can range between 910-260 W/kg. The inclusion of an additional magnet and coil can improve efficiency by up to 3.5 times over typical flapping wing ELAs.