Meeting Abstract
As sidewinders move, only some portions of the snake are in contact with the ground at any time. This changing contact pattern can be modeled as vertical wave coupled to the lateral wave. The result is a sideways motion that causes a broad animal profile along the direction of movement and potentially makes obstacle negotiation more difficult than other modes of undulatory locomotion. Biological experiments revealed that the sidewinder is able to squeeze its body, which we hypothesize is achieved by increasing the amplitude of the horizontal wave, to move past rigidly-anchored vertical posts placed in their path. To test our hypothesis, we created a sidewinding robot from 14 alternating horizontally-and vertically-actuated servo motors connected with 3D printed brackets. The horizontal motors commanded a sinusoidally-varying lateral wave and the sinusoidally-driven vertical motors created a changing contact pattern. We implemented a controller and contact sensing capabilities on our robot, the robot responds to contact by increasing its horizontal amplitude for one full cycle. We positioned the robot at the same initial condition relative to the post for 30 trials each with and without the controller. Without control, the robot was always unsuccessful as its tail end gets caught and the robot spins around the post. With the controller, the robot was able to pull its tail end towards its head to successfully squeeze past 80% of the trials.
