Online adaptation to maximize the tradeoff between tuned vibration absorbers and tuned vibration dampers

Tuned vibration absorbers and tuned vibration dampers are structurally similar, but there are significant differences in their implementation and tuning laws. Lightly damped absorbers are typically applied to primary systems experiencing tonal excitation and achieve a "near-zero" in the frequency response of the primary system. An additional resonant peak is added to the system, such, transients or a mismatch in the absorber's tuned condition may result in poor performance. In contrast, a mini-max approach is used in the design of tuned vibration dampers. The stiffness and damping are designed such that the maximum frequency response across a band of frequencies is minimized. The vibration damper is insensitive to changes in the excitation frequency, but does not generally achieve high performance, due to the added damping in the vibration damper. This paper presents a novel approach whereby the characteristics of both a vibration absorber and a vibration damper are utilized in a single device. During transients, the damping is increased with the goal of helping the system to settle quickly and to avoid operation at resonant conditions. As the vibration becomes tonal, the damping is reduced and good steady state performance is achieved.