Design and Test of a Piezoelectric Inertial Mass Actuator for Active Vibration Control

摘要

Active control of vibrations can outperform passive systems in certain applications, e.g. when broadband damping is requested or when several orders of a periodic disturbance have to be cancelled. To generate dynamic forces for the active control system, inertial mass actuators are frequently used. Mainly, they comprise a force generating element driving a single-degree-of-freedom oscillator which is coupled to the structure to be controlled. Thus, those actuators can also be used for retrofitting of existing structures or for prototyping purposes. In this paper, a design for an inertial mass actuator utilizing piezoceramic actuators is studied. Since those actuators integrate both stiffness and force generation into one element, this enables more compact and mechanically robust designs. With respect to the future integration into industrial applications, standard multilayer piezoelectric actuators are considered to decrease the costs of the system and allow for a high reliability. Usually, an inertial mass actuator should possess a low resonance frequency in order to enable operation over a broad frequency range. Since the stiffness of piezoelectric multilayer actuators is rather high, a lever mechanism is designed which transforms the stiffness of the piezoelectric element into the desired range. An analytical model of the inertial mass actuator is derived and parameter studies are performed to investigate the characteristics of the design. A prototype is set up and the main parameters like resonance and block force are experimentally validated. Finally, the integration of the actuator into an active vibration control system for a lightweight structure is described.