Dynamic Analysis of a Buckling-Type Amplification Mechanism to Maximize the Power Output by Varying the Load Impedance and Control Timing

Abstract

Due to the limited displacement of piezoelectric stack actuators, common practice is to use some form of displacement amplification mechanism. This paper focuses on an externally leveraged mechanism that utilized a buckling motion to achieve large amplification ratios within a single stage. This mechanism interfaces with a sinusoidal gear track that acts as the load. The dynamics of the system are derived and are shown to be fifth order. Due to the significantly nonlinear amplification caused by the buckling phenomenon and the gear, the dynamics are run in simulation to gain insight into the performance of the actuator. There is shown to be an optimal speed at which to run the actuator to maximize the possible power output. Furthermore, due to the simple binary control significant benefits are achieved by varying the control timing based on the velocity to ensure the force and velocity of the output are in phase. Copyright © 2012 by ASME.