Direct Adaptive SSDV Circuit for Piezoelectric Shunt Damping

Abstract

Piezoelectric shunt damping is widely studied to suppress vibration of thin structures via shunting an attached piezoelectric transducer with an electrical impedance. The SSDV (synchronized switch damping on voltage) technique can be used to enhance the damping effect. However, SSDV is not stable in the weak excitation. Although some adaptive SSDV circuits have been developed to tackle the stability problems, additional monitoring devices are required to feed back the vibration strength signal for adjusting the series voltage sources. We here present a new direct adaptive SSDV (DA-SSDV) method without additional excitation level monitoring module, based on the ratio of the maximum piezovoltage and the value of the series voltage sources. A compact DA-SSDV circuit is designed with low-cost off-the-shelf discrete components. The close-loop control of the series voltage sources is realized simply through a passive envelope detector and a resistive voltage divider. Experimental results show the DA-SSDV circuit avoids the stability problems and possesses a good displacement transmissibility around 6.2, a fast voltage adjustment response speed above 5 V/s and a high operation sensitivity with the open-circuit piezovoltage of 540 mV. The DA-SSDV shows great application value in the compact and low-power vibration control systems.