A Residual-Energy-Boundary-Estimation-based Charging Scheduling Scheme in Wireless Rechargeable Sensor Network

The emerging wireless power transfer technology provides a promising approach to address the energy problem in wireless sensor networks. Researchers construct the wireless rechargeable sensor networks (WRSN) by introducing mobile chargers (MC) with high capacity to replenish energy-hungry sensors. Most of the current studies on WRSN focus on scheduling the charging order of sensors based on the advised residual energies of sensors. However, the advised energies are obsolete when MC charge nodes, because of various energy consumption rates of sensors and travel latency of MC. As a result, the charging schedule algorithm may have a bad performance. Aiming to address this problem, this paper proposes a charging scheduling algorithm in WRSN based on the estimation of the residual energy boundary of the sensor node. In the proposed scheme, we first estimate the residual energy boundaries of each sensor to select the energy-critical sensors precisely. Then, we calculate the remain working time of the selected sensors. Thus, we convert the charging scheduling problem to a Vehicle Routing Problem with Time Deadline (VRPTD) and solve it by using the push-forward insertion algorithm. The simulation results show our proposed algorithm performs well under different network sizes.