I. Introduction
Many unmanned aerial vehicles (UAVs) are essential in mission-critical applications, for covering wide disaster sites in emergency cellular networks [1] and for delivering heavy payload in rescue mission and firefighting scenarios [2], [3]. These applications are real-time, and do not tolerate remote control delays from a central controller. Besides, they necessitate reliable control under uncertainty such as wind perturbations, making pre-programed offline control algorithms ill-suited. In view of this, in this paper we focus on the problem of controlling a large number of UAVs in a distributed and online way, so as to achieve 1) the fastest travel from a source to a destination, while jointly minimizing 2) motion energy, and 3) inter-UAV collision, under wind dynamics.