ABSTRACT
Vibration absorption has been a very attractive way of removing oscillations from structures under steady harmonic excitations. There are many common engineering applications yielding such undesired oscillations. The delayed resonator (DR) dynamic absorber is an unconventional vibration control approach which utilizes partial state feedback with time delay as a means of converting a passive mass-spring-damper system into an undamped real-time tunable dynamic absorber. The chapter provides the theoretical fundamentals of DR dynamic absorber, an automatic and presents robust tuning algorithm against uncertain variations in the mechanical properties. The delayed feedback for the DR can be implemented in various forms: position, velocity or acceleration. The DR can be coupled to a mechanical structure and employed as a tuned dynamic absorber to suppress the dynamic response at the location of attachment. Stability is a critical issue in any feedback control. It can be shown that increasing control gain for a given feedback delay leads to instability of the combined system.
