Abstract: With the widespread application of wireless rechargeable devices,wireless power transfer technology has become a key enabler for enhancing device battery life.However,most existing research focuses on optimizing charging efficiency,charging costs,and other charging-related performance metrics.Task-driven charging scheduling has received limited attention.In addition,the majority of charging systems assume homogeneity either in chargers or rechargeable devices,and there is a lack of focus on charging scheduling for mobile rechargeable devices.Considering the heterogeneity of rechargeable devices in real-world scena-rios,this paper proposes a heterogeneous wireless charging model and formalizes the problem of minimizing the maximum return-to-work time of mobile rechargeable devices in heterogeneous wireless rechargeable sensor networks.Initially,it studies the simplified problem of minimizing the maximum return-to-work time under the assumption of ignoring device movement time and energy consumption,and proposes an approximation algorithm.To address the more challenging problem of minimizing the maximum return-to-work time,this paper proposes a heuristic algorithm based on the idea of this approximate algorithm for this problem.The results of extensive simulation and field experiments demonstrate that the proposed algorithm has significant advantages over other algorithms.The proposed algorithm can reduce at most 38.78% maximum return-to-work time of devices comparing with the benchmark algorithms.

Key words: Wireless rechargeable sensor network,Mobile rechargeable devices,Charging scheduling,Heterogeneous wireless charging,Heuristic algorithm