Hierarchical and modular fuzzy architecture for multiple mobile robots

Implementation of autonomous behaviours in mobile robots, using fuzzy logic control, requires formulation of rules that are collectively responsible for necessary levels of intelligence. This collection of rules can be conveniently decomposed and effectively implemented as a hierarchy of fuzzy behaviours. For this purpose, a hierarchical approach to the incremental design of complex robot behaviours based on fuzzy logic is proposed, since the primitive behaviours of individual robots have different aims and this may cause conflict. Some of these behaviours are competitive and some of them are cooperative. This paper also proposes a new behaviour coordination system between the competitive and cooperative methodologies with the aim of taking the advantages of robustness and optimised robot trajectories from both approaches. Simulated and real experiments have been conducted on a team of mobile robots performing a proof-of-concept dynamic target tracking task. The results show an improvement in the overall group performance even in cluttered environment.