Energy-efficient Velocity Control for Massive Numbers of Rotary-Wing UAVs: A Mean Field Game Approach

When a disaster happens in a metropolitan area, wireless communication systems in the area are highly affected, degrading the efficiency of the search and rescue (SAR) mission. An emergency wireless network must he deployed quickly and efficiently to preserve human lives. Teams of low-altitude rotary-wing unmanned aerial vehicles (UAVs) are useful as on-demand temporal wireless networks because they are generally faster to deploy, flexible to reconfigure, and able to provide good communication services with short line-of-sight links. However, rotary-wing UAVs' limited on-board batteries require that they need to recharge and reconfigure frequently during a mission. Therefore, we formulate the velocity control problem for massive numbers of rotary-wing UAVs as a Schrodinger bridge problem which can describe the frequent reconfiguration of UAVs. Then we transform it into a mean field game and solve it with the G-prox primal dual hybrid gradient (PDHG) method. Finally, we show the efficiency of our algorithm and analyze the influence of wind dynamics with numerical results.