A technique to suppress vibration using piezoelectric elements connected to a shunt circuit is called piezoelectric shunt damping. Many studies on this subject have been reported. Among them a technique called switched shunt damping exists. In switched shunt damping developed so far, a switch is placed in the shunt circuit in series to the piezoelectric element, and is used to switch the shunt circuit from an open circuit to a closed circuit. Depending on the elements used in the shunt circuit, various types of switched shunt damping exist. This paper presents a new approach for switched shunt damping on inductance. The presented shunt circuit is composed of a resistance, an inductance and a switch connected in parallel with the inductance. Thus, when the switch is open the shunt circuit becomes an LR circuit, and when the switch is closed it becomes a resistive circuit. Furthermore, switching is operated based on the charge on the piezoelectric element, so that no sensors to conduct the switching are needed. To check the performance of vibration suppression by the proposed method, numerical simulations and experiments are conducted. The results show that the presented switched shunt damping have high performance of vibration suppression.
Strain Sensing With Piezoelectric Zinc Oxide Thin Films for Vibration Suppression in Hard Disk Drives