Energy regenerative active vibration control of cantilever beam using piezoelectric actuator and class d amplifier

Abstract

Active vibration control usually reduces vibration amplitude and mechanical energy of vibrating structure. In the situation, actuator of active vibration control system must re- move energy from vibrating structure. However, the consideration is inconsistent with a common knowledge of active vibration control, active vibration control system needs external power supply to drive actuator. To find an answer to the inconsistency, power flow in an active vibration control system of a SDOF oscillator using a piezoelectric ac- Tuator has been investigated by authors analytically. The piezoelectric actuator is used because it has little internal loss and it makes easy to understand essentials of power flow in the active vibration control system. The investigation shows that the actuator is not consuming power from external source but removing and regenerating energy from the SDOF oscillator. Power consumption of the system is caused by energy loss of the amplifier to drive the actuator. The result implies that an energy regenerative active vibration control system can be realized by reducing energy loss of the amplifier. The energy loss can be reduced by using class D amplifier, high efficient amplifier based on switching operation of semiconductor devices, instead of conventional linear amplifier. The validity of energy regenerative active vibration control system using class D ampli- fier is shown by a numerical simulation. An advantage of proposing method compared to other energy regenerative vibration control methods and semi-active methods is that proposing method can use any controller used in ordinary active vibration control and can achieve the same control performance because difference between ordinary active vibration control methods and proposing method is only type of amplifier. In this pa- per, the validity and the advantage are confirmed by experimental comparison of power flow and control performance of two active vibration control systems using a conven- Tional linear amplifier and a class D amplifier with the same controller and the same actuator.