Evolution of side-winding locomotion of simulated limbless, wheelless robots

Abstract

Inspired by the efficient method of locomotion of the rattlesnake Crotalus cerastes, the objective of this work was the automatic design through genetic programming of the fastest possible, side-winding locomotion of simulated limbless, wheelless artifacts. The realism of the simulation is ensured by employing open dynamics engine (ODE), which allows accounting for all the physical forces resulting from the actuators (muscles), friction, gravity, collisions, and joint constraints. The empirically obtained results demonstrate that the complex side-winding locomotion emerges from relatively simple motion patterns of morphological segments (vertebrae). The robustness of automatically evolved locomotion is verified by (i) the reasonable performance degradation when partial damage to the artifact is inflicted, and (ii) the ability to tackle obstacles. Contributing to the better understanding of the unique, side-winding locomotion, this work could be considered as a step toward building real limbless, wheelless robots, featuring unique engineering characteristics, which are able to perform robustly in difficult environments.