Wireless power transfer has given a promising alternative to replenish battery-powered wireless sensor networks (WSNs). We can employ mobile vehicles, robots, or unmanned aerial vehicle as mobile chargers to wirelessly charge sensor nodes. Most of previous works either assume that a mobile charger can charge only one sensor node at a time, or optimize for charging delay, radiation safety, etc. In this paper, we consider a fundamental problem: given one mobile charger that can charge multiple sensor nodes simultaneously, how we can schedule it to charge a given WSN to maximize the energy usage effectiveness (EUE)? We propose a novel charging paradigm, Overlapped Mobile Charging (OMC), the first of its kind to the best of our knowledge. Firstly, OMC clusters sensor nodes into multiple non-overlapped sets using k-means evaluated by the Davies–Bouldin Index, such that the sensor nodes in each set have similar recharging cycles. Secondly, for each set of sensor nodes, OMC further divides them into multiple overlapped groups, and charges each group at different locations for different time durations to make sure that each overlapped sensor node just receives its required energy from multiple charging locations. Simulations confirm the advantages of OMC in terms of EUE.

无线电力传输为补充电池供电的无线传感器网络 (WSN) 提供了一个有前途的替代方案。我们可以使用移动车辆、机器人或无人机作为移动充电器，为传感器节点无线充电。以往的大部分工作要么假设移动充电器一次只能为一个传感器节点充电，要么针对充电延迟、辐射安全等进行优化。在本文中，我们考虑一个基本问题：给定一个可以为多个传感器充电的移动充电器节点同时进行，我们如何安排它为给定的 WSN 充电以最大化能源使用效率 (EUE)？我们提出了一种新颖的充电模式，重叠移动充电 (OMC)，据我们所知，这是同类中的第一个。首先，OMC 使用由 Davies–Bouldin 指数评估的 k-means 将传感器节点聚类成多个非重叠组，这样每个组中的传感器节点都具有相似的充电周期。其次，对于每组传感器节点，OMC进一步将它们分成多个重叠的组，并在不同的位置为每个组充电不同的持续时间，以确保每个重叠的传感器节点仅从多个充电位置接收到其所需的能量。仿真证实了 OMC 在 EUE 方面的优势。并在不同的位置为每个组充电不同的持续时间，以确保每个重叠的传感器节点仅从多个充电位置接收所需的能量。仿真证实了 OMC 在 EUE 方面的优势。并在不同的位置为每个组充电不同的持续时间，以确保每个重叠的传感器节点仅从多个充电位置接收所需的能量。仿真证实了 OMC 在 EUE 方面的优势。