Frequency adaptive piezoelectric shunt damping system for vibration suppression of precision mechanism

Based on the negative impedance converter, a frequency-adaptive simulated inductor circuit was proposed and applied to the design of piezoelectric shunt damping system to improve its multi-mode vibration suppression. With the advantage that the impedance of the inductor can vary with the vibration frequency of the structure, the shunt damping circuit always works at its resonant state in a manner analogous to a mechanical vibration absorber. To demonstrate the feasibility and effectiveness of multi-mode vibration suppressing of this piezoelectric shunt damping system, the multiple mode vibration control experiments on the actuator of a hard disk driver was performed. The results show that with the proposed frequency-adaptive piezoelectric shunt damping system, the transfer function amplitude of the first three modes of the actuator were decreased by about 8.15 dB, 12.06 dB and 2.11 dB respectively. The impact of the circuit configurations and the impedance of elements of the simulated inductor on the vibration reduction efficiency were studied.