Enhanced synchronized switch damping control to cancel out the beating phenomenon

Synchronized Switch Damping control is one of the most interesting solutions for vibration suppression proposed in the last years. It is based on the electromechanical coupling provided by piezoelectric actuators. By connecting the piezoelectric actuator to a shunting circuit (typically a RL one) and properly switching between open and closed circuit, an equivalent hysteresis cycle is created and the structure energy is dissipated. It is known that, in order to maximize the damping effect the resistance of the circuit must be reduced. Anyway, as shown in literature, this effect is limited by the presence of a beating effect when the resistance is lower than a certain threshold. The aim of this paper is to analyse the beating phenomenon in order to propose new solutions to cancel it. The paper will show some innovative solutions modifying the shunting circuit to avoid the beating phenomenon and thus increase the control performance. These solutions will be described from a theoretical point of view and then tested to demonstrate their effect.