Semi-passive random vibration control based on statistics

This paper considers the development of an enhanced control strategy for a semi-passive piezoelectric damping device (SSD or pulse switching). Following the proposed approach, the voltage or displacement signal is analysed during a given time window and the statistically probable displacement or voltage-level threshold is determined from both the average and standard deviation of the signal during the observation period. The voltage step still occurs on a local maximum of the signal but only above the statistically defined threshold. A significant decrease in vibration energy is demonstrated experimentally and theoretically in the case of a clamped beam excited by random noise. It is shown that in the case of multimodal vibration, all of the modes are controlled and preferentially those corresponding to the highest displacement amplitudes. (C) 2007 Elsevier Ltd. All rights reserved.