Analytical and experimental studies on particle damper used for tremor suppression

Abstract

Tremor is an involuntary movement that makes many patients suffer, and passive absorbers used in wearable robot are proved to be effective for tremor suppression. A particle damper is a kind of a passive vibration control device taking advantage of energy dissipation and momentum exchange caused by particle collisions. To apply particle damping technology in reducing tremor amplitude in the human hand, this study establishes a mechanical model of the particle damper for tremor suppression and obtains its steady-state solutions under simplified tremor excitation. The accuracy of steady-state solutions and the particle damper effectiveness in reducing tremor is validated by numerical simulations and experimental studies. To further explore its damping mechanism, some important damper parameters are then analyzed. It is shown that increasing the particle mass leads to an increase of the particle damper performance for tremor suppression, but it has an upper limit. The provided damping of the particle damper becomes approximately independent of the tremor frequency and the tremor amplitude within a certain range, which indicates that a particle damper with reasonable design is suitable for tremor suppression.