Vibration control of structures with self-sensing piezoelectric actuators incorporating adaptive mechanisms

In a piezo-based self-sensing actuation (SSA) configuration,, the control signal is mixed with the signal due to mechanical response. The success of SSA relies on the extraction of that mechanical response from the mixed signal. Owing to the relatively high amplitudes of those two signals and the ambience varying property of the equivalent capacitance of the piezoelectric element, a fix designed bridge circuit in the SSA configuration would extract a corrupted mechanical response under the variation of the piezoelectric capacitance. This would degrade the system performance or even destabilize the closed loop system. In this paper, an adaptive compensation is proposed to combine with the SSA technique to develop a vibration controller that is capable of extracting, the true sensing signal due to structural deformation. The results of this study illustrate that the combined design can simultaneously suppress the structural vibration during the piezoelectric capacitance variation.