The pros and cons of flocking in the long-range "migration" of mobile robot swarms

In this paper, we study how flocking affects the accuracy and speed of individuals in long-range "migration". Specifically, we extend a behavior that can generate self-organized flocking in a swarm of robots to follow a homing direction sensed through the magnetic field of the Earth and evaluate how the final points reached by the flock are scattered in space and how the speed of the flock is affected. We propose that four factors influence the performance of migration, in the proposed behavior, namely: (1) averaging through heading alignment behavior, (2) disturbances caused by proximal control behavior, (3) noise in sensing the homing direction, and (4) differences in the characteristics of the individuals. Systematic experiments are conducted to evaluate the effects of these factors using both physical and simulated robots. The results show that although flocking reduces the speed of an individual, it increases the accuracy of "migration" for flocks that are larger than a certain size. (C) 2010 Elsevier B.V. All rights reserved.