An Unconventional Direction for Vibration Suppression :
Delayed Feedback Vibration Absorbers

In this talk a summary of development over the last 7 years is presented. The departure point of the program is a delayed feedback control structure which sensitizes a passive vibration absorber. The new absorber is a tuned resonator and can suppress oscillations at its resonance frequency and at the point of attachment to the primary structure. It is named the "Delayed Resonator" (DR). It has decoupled control features from the primary system and shows real time tuning features. The DR can be further tuned to dual resonances, thus enabling the suppression to be effective at two distinct frequencies.

In a broader treatment the delayed feedback structure can be used as a tool for pole placement. Several research results including centrifugal vibration absorbers, optimally tuned wide-band absorbers are included along this line.

Experimental and analytical results are presented.