Incremental mission allocation to a large team of robots

In the MARTHA project, a large number of robots in a harbour are given the global task of transporting containers from one area to another. The global decision-making process of allocating robots to those predefined tasks can be viewed as a scheduling and resource allocation problem, which is addressed here in a centralised way. Imprecision of temporal constraints makes it meaningless to search for a strict optimal schedule. The authors' approach interleaves task allocation and execution, scheduling in a sliding short-term horizon, as the execution process runs, and providing near-optimal solutions. For large applications the complexity of temporal management is a crucial issue. The authors present a graph decomposition technique, leading to nearly-constant time temporal propagation, without any loss of information.