Design of a self-adjusting and self-powered dynamic vibration absorber

In this study, an adaptive self-tuning base-excited resonator, which can be used as a vibration absorber system, is described. A self-powered tuning subsystem that only uses external vibration energy is designed. Hence, no electronic sensor or actuator is used and the fully mechanical system functions without an external electrical source. The system contains a lever, whose effective length can change, which in turn changes the resonance frequency of the system. When the resonance frequency matches the excitation frequency, the instant center of zero velocity of the lever coincides with the hinge attached to the base. As the excitation frequency changes, the system changes the lever ratio in such way to bring out resonance frequency to coincide with the excitation frequency to absorb excitation at the base and transfer the vibration to the main mass of the absorber. The system self-tunes to the optimum lever ratio for maximum vibration output. The equation of motion of the system is derived and the location of the instant center is calculated analytically. In addition, simulations are carried out to compare and confirm the response of the system. The numerical simulations verify that the resonance condition is achieved in the working frequency range.