Multi-node Mobile Charging Scheduling with Deadline Constraints

In this work, we study the mobile charger scheduling problem for multi-node charging with deadline constraints. In that, we aim at scheduling the charger to maximize the effective charging utility in dealing with the mismatch between time and spatial constraints. The local charging spots selection and globe traveling path should be jointly optimized, which is APX-hard. Nevertheless, our problem becomes much more complex with deadline constraints. To handle aforementioned challenges, we combine the spatial and temporal relevancy into a bipartite graph, and incorporate the multi-charging strategy instead of serving nodes strictly by the non-soft charging demands. We formulate the effective charging utility maximization problem into a monotone submodular function maximization subjected to a partition matroid constraint, and propose a simple but effective 1/2-approximation greedy algorithm. The results show that our scheme outperforms Early Deadline First (EDF) by 37.5%.