Optimization of the frequency tracking scheme for an adaptively tuned vibration absorber

Vibration absorbers can absorb vibration energy and reduce the vibration amplitude of the primary system. With adaptive tuning, an adaptively tuned vibration absorber (ATVA) can track the dominant frequency of the external excitation, and reduce the vibration response amplitude of the primary system under variable-frequency external excitation. To realize the optimal vibration reduction performance, the 100% frequency tracking scheme of the adaptively tuned absorber must be optimized. In this regard, a dynamic model of an undamped primary system and a vibration absorber is established based on vibration absorption theory, and alternative tuning schemes for these absorbers are investigated in this paper. Using ATVA with the 100% frequency tracking scheme as a reference, a frequency tracking scheme is optimized by the segmented intercept optimization method. This optimization method continuously tunes the ratio of the absorber natural frequency and external excitation frequency to minimize the response in the variable-frequency vibration regions. Hilbert-Huang transform (HHT) time-frequency analysis is performed on the vibration response to reveal the vibration reduction mechanism of the improved vibration absorber. The vibration reduction effects are verified by comprehensive analysis results and experimental results.