A simple modification to improve the immunity of linear electromagnetic actuators against disturbing magnetic field

Abstract

Linear electromagnetic actuators (LEAs), which conduct linear physical movements driven by electromagnetic force, are widely used in various applications. However, LEAs are very sensitive to magnetic fields because of their ferromagnetic materials. The failure of LEA under magnetic field interference is a potential threat to the system reliability and safety. Therefore, it is significant to reduce magnetic field interference on LEAs. In this paper, a novel method to increase the immunity of LEAs against disturbing magnetic field by simply adding two small iron legs is proposed. The iron legs change the magnetic field distribution in LEA, and significantly reduce the magnetic field interference of LEA. Compared with conventional magnetic shielding, the proposed method shows great advantages of higher failure threshold, smaller space occupation and lower material cost. Experimental tests are also performed to verify the theoretical analysis, and the results fit well, which prove the effectiveness of this method. In general, this paper provides a simple and effective method to improve the immunity of LEAs against disturbing magnetic field, and the idea can also be extended to the antimagnetic design of other similar devices.