Rendezvous Scheduling for Charging Coordination Between Aerial Robot - Mobile Ground Robot.

This paper studies the problem of rendezvous scheduling between an energy-limited aerial robot (AR) and a mobile ground robot (MGR). If the AR cannot complete its mission in a single sortie, it has to recharge at scheduled locations and times with the MGR acting as a mobile charging station. Differing from previous work, the visit order of the waypoints is assumed to be determined a priori using one of the available algorithms for pathfinding or area coverage. We consider two alternative cases depending on whether the AR can land prior to the arrival of the MGR or it has to hover in the air and wait for its arrival. Our approach to each is motivated by the principle of optimality - namely the corresponding constrained optimization problem is decomposed into smaller problems whose solutions are then integrated together. Their solutions are found from a binary search tree of charge selections that evolves iteratively using a tree sort algorithm. The advantage of this approach is that as the focus is on the scheduling aspect, the algorithm becomes relatively more tractable and realistically applicable. Our simulation results demonstrate that the optimal rendezvous schedule can be determined in realizable time even for large-scale missions.