Meeting Abstract
Flying snakes of genus Chrysopelea are able to glide by flattening their entire body and using it as a morphing wing. The most prominent feature of the snake’s gliding behavior is undulation, in which the snake assumes an S-shaped configuration and sends high-amplitude traveling waves posteriorly down the body. The role of this highly dynamic postural reconfiguration in the snake’s control system is unknown; in particular, how the snake remains stable in the pitch, roll, and yaw directions is not understood. Because undulation periodically redistributes mass and aerodynamic forces, and therefore provides ‘averaged’ bilateral symmetry, it has been suggested that undulation is required for stability. Here, we investigated the fundamental dynamics and stability characteristics of an airborne flying snake by developing a series of theoretical n-chain multi-body models. The models were simulated in 3D under the action of gravity and aerodynamic forces using experimentally obtained lift and drag coefficients. Linearization of the equations of motion about their equilibrium solutions showed controllability of those solutions, and stable glide trajectories of the nonlinear equations were found with a closed-loop control. Our results show that it is possible for a chain of snake-like airfoils with sufficient number of links to be controlled to move through the air while maintaining a static configuration. This theoretical modeling suggests that undulation is not strictly necessary for flying snakes to maintain stability while gliding. Partially supported by NSF 1351322.
