Coil-based Electromagnetic Damper and Actuator for Vibration Suppression of Cantilever Beams

Abstract

In this study, both an eddy current coil damper and an electromagnetic actuator were developed for the vibration suppression of a cantilever beam integrated with a copper coil and a permanent magnet. The control system for the vibration suppression of the electro-magneto-mechanically coupled beam that consists of a coil attached to an aluminum beam and a permanent magnet installed below the coil was proposed. Alternatively, the conductive coil can be passively and actively used as a damper and an actuator. The effects of various coil shapes including a cylindrical tube, a square tube and a circular sheet were investigated to determine optimal vibration suppression for the cantilever beam. The frequency response function of a beam with the theoretical model of the magnetic eddy current damping system was predicted and its accuracy was compared to the experimentally measured frequency response. Also, the results of the active control with a positive position feedback method were compared with those of the passive eddy current dampers with open and closed circuits. The experimental data showed that the tube type coils had much higher vibration suppression efficiency than the sheet type coil and the active vibration control strategy can be alternatively used to improve the electromagnetic damper system.