Scheduling for multi-robot routing with blocking and enabling constraints

Abstract

This paper considers the problem of servicing a set of locations by a fleet of robots so as to minimize overall makespan. Although motivated by a specific real-world, multi-robot drilling and fastening application, the problem also arises in a range of other multi-robot domains where service start times are subject to precedence constraints and robots must be routed in space and time to avoid collisions. We formalize this general problem and analyze its complexity. We develop a heuristic local search procedure for solving it and analyze its performance on a set of synthetically generated problem instances, some of which capture the specific structure of the motivating drilling and fastening application, and others that generalize to other application settings. We provide a differential analysis of our local search procedure and a comparison to other approaches to demonstrate the efficacy of the proposed heuristic.