Task assignment algorithms for unmanned aerial vehicle networks: A comprehensive survey

Unmanned aerial vehicles (UAVs) have significant prospects in a plethora of public and civic spheres. Recently, UAVs have focused primarily on applications where human presence is either impossible or hazardous. A swarm of small UAVs can cooperatively complete operations more proficiently and economically than a single large UAV. However, many issues must be resolved before stable and reliable multi-UAV networks can be realized. Task assignment in fleets of UAVs is concerned with cooperative decision-making and control. UAVs possess various functional abilities and kinematic constraints while carrying limited resources onboard. UAVs are nominated to execute multiple sequential tasks supportively on numerous ground targets. The prime objective of task assignment is to minimalize the task accomplishment time and UAV energy consumption. To date, several task assignment algorithms have been designed for UAV networks, and they are comprehensively surveyed in this paper in terms of their main ideas, operational features, advantages, and limitations. These task assignment algorithms are then compared in terms of their significant characteristics and performance factors. To the best of the authors' knowledge, no survey on task assignment techniques for different UAV missions currently exists in the literature. We also discuss open issues and challenges and then suggest projections for task assignment algorithms concerning possible future directions.