Development And Experiment Study Of Electromagnetic Active Vibration Absorber

The development of dynamic vibration absorber has a history of nearly a hundred of years,and it is widely used in the field of automotive vibration control.The active vibration absorber can directly generate a force which is equal in magnitude but opposite in direction to the excitation force so that it can offset the influence of the excitation force to the mechanical or structural system.Therefore,active vibration absorber can damp the vibration in a wide frequency range and it has many advantages compared with the passive or semi-active vibration absorber as well.In this paper,an electromagnetic active vibration absorber was studied.Firstly,the electromagnetic force characteristics of three types of electromagnet structure were analyzed using the finite element analysis software Ansoft Maxwell.A better electromagnetic structure was obtained through the analysis and the moving iron and the fixed iron were designed based on this structure.Through the comparison between the simulation and experiment result,the moving iron and fixed iron were proved to have a better electromagnetic force characteristic that basically met the requirements.Secondly,the structure of the electromagnetic active vibration absorber was described in details.Then the modal test of the electromagnetic active vibration absorber was conducted and its vertical natural frequency was obtained.Experiment studies on the output force characteristics of the electromagnetic active vibration absorber showed that the output force of the vibration absorber was basically a harmonic force.Therefore,the electromagnetic active vibration absorber could be used to damp the vibration of mechanical or structural system which was excited by harmonic force.Finally,theoretical analysis and experimental study on vibration reduction of the electromagnetic active vibration absorber were conducted.The influence of the phase,amplitude and frequency of the output force of the vibration absorber were analyzed through theoretical derivation and experiment study.Based on the PID control method,the active vibration absorber was used to control the vibration of the cantilever beam.The study showed that the electromagnetic active vibration absorber had a significant damping ability in a wide frequency range.