Using a co-evolutionary approach to automatically generate vertical undulation and lateral rolling motions for snake-like modular robot

This paper explores the use of evolutionary algorithm approach to automatically design and optimize the snake-like modular robot to acquire with the vertical undulation locomotion and lateral rolling moving behaviour. A hybridized Genetic Programming and self-adaptive Differential Evolution algorithm is implemented in this work to simultaneously co-evolve both the morphology and controller of the snake-like modular robot throughout the artificial evolutionary process. This paper also illustrates on how the overall structure and control strategy of the snake-like modular robot is being designed in order for the snake-like modular robot to perform the particular locomotion. Moreover, different fitness functions had also been modelled for each locomotion experiment in computing the performance score of the snake-like modular robot. Interestingly, it was found out that the snake-like modular robot can actually travel for longer distance using vertical undulation locomotion. It was also found out that the rolling movement of the snake-like modular robot can be achieved by motors attached only in pitch and yaw axis. In conclusion, promising results were obtained in this work showing that the co-evolving evolutionary algorithm illustrated in this work is feasible to be implemented to automatically design and optimize the modular robot to evolve with various locomotion capabilities.