Evolution, Robustness, and Adaptation of Sidewinding Locomotion of Simulated Snake-Like Robot

Inspired by the efficient method of locomotion of the rattlesnake Crotalus cerastes, the objective of this work is automatic design through ge- netic programming, of the fastest possible (sidewinding) locomotion of simu- lated limbless, wheelless snake-like robot (Snakebot). The realism of simula- tion is ensured by employing the Open Dynamics Engine (ODE), which facili- tates implementation of all physical forces, resulting from the actuators, joints constrains, frictions, gravity, and collisions. Empirically obtained results dem- onstrate the emergence of sidewinding locomotion from relatively simple mo- tion patterns of morphological segments. Robustness of the sidewinding Snake- bot, considered as ability to retain its velocity when situated in unanticipated environment, is illustrated by the ease with which Snakebot overcomes various types of obstacles such as a pile of or burial under boxes, rugged terrain and small walls. The ability of Snakebot to adapt to partial damage by gradually improving its velocity characteristics is discussed. Discovering compensatory locomotion traits, Snakebot recovers completely from single damage and recov- ers a major extent of its original velocity when more significant damage is in- flicted. Contributing to the better understanding of sidewinding locomotion, this work could be considered as a step towards building real Snakebots, which are able to perform robustly in difficult environments.