An Implicit Model for Snake Robot Locomotion and Gait Optimization

Abstract

The present study aims to develop dynamic models suitable for the analysis and design of robotic snakes. Specifically, this research presents an implicit model with a high degree of design flexibility, namely the ability to change the number of links and to vary friction in the model formulation. The implicit model is validated numerically by comparison to an explicit model with small number of links. The validated implicit model is then used to establish the optimal gait for a six-link snake robot to achieve locomotion with minimal power consumption. An iterative search is conducted over a range of operational parameters — amplitude of angular displacement inputs at each joint, relative phase lag between the sinusoidal displacement inputs at the joints, and frequency of sine-wave input — to determine the optimally efficient gait. Results indicate that, for a particular forward velocity, an optimal gait exists that minimizes power consumption. This optimal solution is validated experimentally via tests performed on a six-link snake robot.