Multi-Vehicle Charge Scheduling and Routing with a Mobile Charging Host

Teams of unmanned (aerial and/or ground) vehicles offer opportunities to extend mission or task capabilities and safety within resource constrained environments. For large scale missions, covering large areas and/or a long span of time, these teams are limited by the individual vehicle's range. To extend the overall team range in situations where fixed refueling/recharging stations are not feasible or cost effective, we propose incorporating a mobile charging host vehicle into the team of unmanned vehicles. We build on variants of the vehicle routing problem to pose the corresponding charge scheduling and routing problem. Therein, we update the mission plan for worker vehicles by incorporating rendezvous with a mobile charging host in order to optimize total team energy utilization, while minimizing mission delay and accounting for variable power charging protocols. Compared to a rule-based charge scheduler, our proposed optimization scheme realizes up to an 8% reduction in energy consumption and upwards of a 60% reduction in mission delay.