  A system of cooperative unmanned aerial vehicles (UAVs) is a group of agents
interacting with each other and the surrounding environment to achieve a
specific task. In contrast with a single UAV, UAV swarms are expected to
benefit efficiency, flexibility, accuracy, robustness, and reliability.
However, the provision of external communications potentially exposes them to
an additional layer of faults, failures, uncertainties, and cyber-attacks and
can contribute to the propagation of error from one component to other
components in a network. Also, other challenges such as complex nonlinear
dynamic of UAVs, collision avoidance, velocity matching, and cohesion should be
addressed adequately. The main applications of cooperative UAVs are border
patrol; search and rescue; surveillance; mapping; military. Challenges to be
addressed in decision and control in cooperative systems may include the
complex nonlinear dynamic of UAVs, collision avoidance, velocity matching, and
cohesion. In this paper, emerging topics in the field of cooperative UAVs
control and their associated practical approaches are reviewed.
