Adaptive Switch Timing Control Law for Optimal Displacement Reduction via SSDI

Abstract

In the conventional implementation of synchronized switch damping (SSD), the switches are intended to occur at every displacement extrema. However, recent work reveals that switching at the vibration peaks is only optimal for displacement reduction under resonance excitation. In general, the optimal switch timing is dependent on the excitation frequency along with the electromechanical coupling and modal damping of the structure. This work seeks to develop a control framework that searches through the possible switch times to find the optimal switch time for synchronized switch damping on an inductor (SSDI) under steady state excitation. The control law does not need any knowledge of the system, only requiring the voltage of the piezo actuator to develop a displacement estimate that is minimized by adjusting the switch timing. Furthermore, the controller naturally senses changes in the excitation and adapts the switch timing to best reduce displacement under the new excitation.