Self-sensing actuation using online capacitance measurement with application to active vibration control

Self-sensing actuation has been extensively used in vibration control of flexible structures over the last three decades. Positive position feedback controller has been commonly used in this field due to the robustness against spillover phenomena. Piezoelectric clamped capacitance is the most important parameter that affects the performance of this technique. In this study, the effect of capacitance change on performance and stability of a self-sensing system with positive position feedback controller is investigated. Based on this analysis, some modifications are suggested to increase the stability of the closed-loop system against capacitance change. An online Fourier transform–based capacitance measurement method is used, which guarantees good performance and stability of closed-loop system in the presence of capacitance change. Experimental results are also presented to show the effectiveness of this method in vibration control of cantilever beam.