Self-excited vibratory system for a flutter mechanism

Abstract

This paper describes theory and experimental verification of a self-excited vibratory system which can excite lower mode of the original passive system of a flutter wing mechanism as a hypothetical model of insect wings. In order to realize a self-excitation system of natural mode of vibration, we proposed two kinds of positive velocity feedback with nonlinear negative damping: Van der Pol (VDP) type and negative Coulomb friction (NCF) type. In order to drive only the lower mode, a low pass filter and cross feedback methods were proposed. It was found that the analytical results were in good agreement with the experimental ones, and that the NCF type can excite the limit cycle motion more rapidly than the VDP type. Robustness of the self-excited flutter motion to the change of mass parameter was also demonstrated.