Wireless rechargeable sensor networks (WRSNs) have the potential to significantly enhance the efficiency of existing transportation systems and are rapidly becoming a key element of intelligent transportation systems (ITSs). The use of wireless charging (WC) with unmanned aerial vehicles (UAVs) is an innovative approach for supplying power for WRSNs. This strategy allows the ongoing deployment of WRSNs to previously unreachable sites and decreases the maintenance requirements for continuous WC networks. UAVs, however, have a short battery life and should return to their base stations on a regular basis for recharging. Furthermore, battery capacity constraints in these devices restrict their capability to power sensor networks across a vast region. To accommodate the limits of UAVs in the development of the UAV-based WRSNs charging scheme, we propose a consistent and cost-aware energy procurement framework for a UAV powered concurrently by laser beams emitted by locally deployed laser beam directors (LBDs) and local renewable energy (RE) sources. The UAV intends to reduce its total energy cost for a given operation cycle by optimizing the quantities of energy acquired from its internal battery and laser beams at each time period. Furthermore, we estimate the amount of extra RE that can be used to power the sensors in WRSNs using wireless power transfer (WPT) technology.
