Dynamic behavior of LIPCA and modification of a four-bar linkage for mimicking insect flapping frequency

Abstract

This paper describes an approach to increase the flapping frequency of a previously developed flapper actuated by Lightweight PiezoComposite Actuator (LIPCA) to mimic the flapping frequency of Allomyrina Dichotoma of which flapping frequency is typically 30Hz. To achieve this purpose, the dynamic characteristics of the LIPCA and modification of a four-bar linkage have been studied. The parametric study showed that an appropriate combination of linkage lengths can provide a better moment transmission for a given flapping angle amplification, thus the flapping frequency could be increased. A newly designed four-bar linkage system was fabricated based on the parametric study and then tested to verify the possibility. The test results showed that the optimal flapping frequency of the modified flapper was measured to be about 15 Hz, which is about 50% increases compared to that of the previous flapper. The modified flapper could also produce 3.02 gram force in vertical direction with 97 degree of flapping angle at the optimal frequency.