Effects of a Single Moving Mass on the Dynamics of a Samara-Inspired Vehicle

Abstract

Nature has often been used as a source of inspiration for dynamics. The simple yet elegant design of the single-winged samara seed has been theorized as a form of evolution that has enabled the distribution of large seeds to greater distances in the presence of prevalent wind conditions resulting from the characteristic stable autorotation that slows vertical descent. This behavior has interested engineers and technologists alike in application areas that include sensor network distribution over large areas as well as precision package-drop operations. While past biomimetic samara-inspired vehicle designs have focused on the use of wing flaps, wingtip rudders, and propellers, this work explores for the first time the use of a single moving mass actuator as a potential means of control without external actuating surfaces. A six degree of freedom time-varying triple-mass rigid body model was derived for a samara-inspired vehicle with a moving mass actuator on a linear rail to assess the possible use of moving mass control in future samara autorotating wing vehicle design. For the model, blade element theory was used to define the forces and moments used for the equations of motion. The results of four case studies demonstrated an ability to laterally displace the samara as well as affect the biased direction of the displacement that shows promise for future vehicle design.