Numerical Simulation of the Motion of a Snake Robot

Authors: Aksel Transeth (NTNU,SINTEF), Remco Leine

The aim of this joint research project is to numerically simulate the snake robot “Aiko”, developed at the Norwegian University of Science and Technology (NTNU)/SINTEF Advanced Robotics Laboratory. The snake robot is a wheel-less robot consisting of 11 cylindrical links and 10 Kardan-joints. Snakes utilize irregularities in the terrain, such as rocks and vegetation, for faster and more efficient locomotion. This motivates the study of a snake robot which is not only in unilateral contact with the ground but which can also be in contact with obstacles. A non-smooth 3-D mathematical model of the snake robot is developed and experimentally validated. The model is based on the framework of non-smooth dynamics and convex analysis that allows us to easily and systematically incorporate unilateral contact forces and friction forces based on Coulomb’s law of dry friction.  A back-to-back comparison between numerical simulations and experimental results is presented. Simulation and experimental results for the serpentine motion patterns lateral undulation and sidewinding as well as obstacle-aided locomotion are presented. Furthermore, it is shown that the snake robot is able to move forward faster and more robustly by exploiting obstacles.

Simulation results (left) and experimental results (right) of the sidewinding motion pattern.

Simulation results (bottom) and experimental validation (top) of obstacle-aided locomotion.