Variable frequency harmonic vibration suppression using active vibration absorption

Abstract

Passive   dynamic   vibration   absorbers   have   been   extensively   used   for   harmful  vibration  attenuation  in  many  practical  engineering  systems.  The  applicability  of  these  passive  vibration  absorption  devices  is  limited  to  a  specific  narrow  operation  frequency  bandwidth.  In  this  article,  a  novel active  vibration  absorption  scheme  is  proposed  to  extend  the  vibration  suppression  capability  of  a  passive  mass-spring-damper  absorber  for  any  excitation  frequency,  including  interest  resonant  harmonic  perturbation forces.  The  central  foundations  of  a  passive  absorber  are  exploited  in  the  design stage of the presented absorption scheme. Thus, the active absorption device applies forces on the protected mechanical system that counteract the unknown perturbation forces, conserving the vibration attenuation property of the passive absorber. The perturbation force is estimated on-line using an extended state observer proposed in this work. Simulation results are included to show the efficiency of the active vibration absorption scheme to reject completely  unknown  resonant  and  chaotic  forced  vibrations  affecting  the primary mechanical system, and to prove the effectiveness of the estimation of exogenous perturbation forces.