Placing Directional Wireless Chargers With Limited Mobility

This paper studies the problem of (?)lacing directional w(?)reless chargers with (?)imited m(?)bili(?)y(PILOT),that is,given directional wireless chargers with limited mobility and a set of static rechargeable devices on the 2D plane,determine the deployment po-sition,staying position and direction of the charger,and charging time to maximize the overall charging utility of the all devices.In order to solve PILOT,an algorithm with an approximate ratio of(1/2-?)is proposed here.Firstly,a solution to approximate the nonlinear charging power of a wireless charger is proposed,that is,the charging power of the charger is approximated as a piecewise constant function.This scheme can transform the continuous staying position and direction of the charger into a lim-ited discrete area.Secondly,a geometric method was proposed to further reduce the infinite solution space of candidate deployment locations to a limited space without degrading performance,and convert PILOT to mixed integer nonlinear programming problem(MINLP).Finally,a greedy algorithm based on linear programming is used to solve the MINLP.Simulation and field experimental results show that our algorithm is at least 23.11%higher than the performance of the five comparison algorithms.