Adaptive Charging With Beam Steering

Abstract

With the maturation of wireless power transfer technology, Wireless Rechargeable Sensor Networks (WRSNs) have been able to provide a continuous energy supply by scheduling a Mobile Charger (MC). However, traditional charging modes suffer from fixed charging areas that lack the ability to adapt to variable sensor distributions. This inflexibility yields a gap between energy supply and utilization, resulting in relatively low charging efficiency. To address this issue, we propose an adaptive charging mode that utilizes beam steering to dynamically adjust the charging area, thereby catering to different sensor distributions encountered during the charging process. First, we build a dual-symmetric steering charging model to describe the characteristics of dynamic beam steering, enabling precise manipulation of the charging area. Then, we develop a charging power discretization based on steering angle and charging distance to obtain a finite feasible charging strategy set for MC. We reformalize charging utility maximization under energy constraints as a submodular function maximization problem, and propose an approximate algorithm to solve it. Lastly, simulations and field experiments demonstrate that our scheme outperforms other algorithms by 43.9% on average.