A NOVEL ACTIVE VIBRATION ABSORPTION TECHNIQUE - DELAYED RESONATOR

A new concept of active vibration absorption for dynamic structures is presented. This new methodology, delayed resonator, originates from a proportional position feedback excitation utilized on an otherwise conventional mass-spring-damper absorber. The critical feature of the technique is utilization of a controlled time delay in the feedback loop, which is traditionally looked upon as an undesirable element in dynamic controls. The proper selection of this delay and feedback gain converts the absorber into a resonator at a desired absorption frequency-hence the name delayed resonator. Two features which make this technique unique and superior to the other state-of-the-art vibration suppression methodologies are that: (a) it removes oscillations of the primary structure for a very wide range of frequencies and (b) the tuning of the absorber is done in real time. This paper lays out the theoretical foundations for the delayed resonator and explains the control decision process for the delay and gain. Dynamic stability issues are also discussed. Simulations are presented proving the strength of the concept, and remarks on avenues for future research are given.