Taking swarms to the field: A framework for underwater mission planning

Large scale missions in unpredictable and unstable underwater environments are beyond the capabilities of a single intelligent and complex robot. Relying on one robot is far from optimal as loss of the unit means failure of the whole mission. On the contrary, robotic swarms depend on large numbers of simple, cheap, and error-prone robots that exhibit global desirable features like fault-tolerance, scalability, and robustness. The study of underwater robotic swarms from the overall mission-planning perspective has been very limited. Planning specific parts of a mission has mostly been the focus of previous research. We propose a general framework for designing and planning underwater swarm missions. We break a typical mission down into its primary constituents and study the requirements for each sub-mission separately. Initially, the swarm self-organizes to form a shape that maximizes residual energy and minimizes water resistance during transport towards the target. This is followed by path planning and shape maintenance, in which the swarm strives to maintain its collective shape and move in cohesion on a collectively-selected path. Next, another self-organization phase takes place to optimize mission-core accomplishment at the target. Remaining phases, in the back trip, are the counterparts of the first two. Related work in each phase is presented and discussed and future work is also highlighted.