Semi-active vibration control based on unsymmetrical synchronized switching damping: Circuit design

An unsymmetrical switch circuit is designed for semi-active control method based on synchronized switching damping principle of piezoelectric actuators. A bypass capacitor and an additional switch are used to realize unsymmetrical bipolar voltage. The control logic of the switches is introduced in detail and the switched voltages, which directly influence the control performance, are derived as functions of the vibration amplitude and the outputs of the voltage sources. Experiments were carried out to verify the designed circuit and the theoretical results of the switched voltage. For simplification of experimental conditions, the beam is fully clamped and the voltage is fully generated by the voltage source. The influence of the voltage source and bypass capacitor on the actuator was investigated. Experimental results show that the circuit leakage is a critical factor to the amplification of actuator voltage. The voltage ratio increases with increasing bypass capacitance, but its increasing rate decreases.