A Review of Recent Advances in Coordination between Unmanned Aerial and Ground Vehicles

Coordination between unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) has received increasing attention in recent years. The list of successful applications of UAV-UGV coordination systems is growing and demonstrates that UAV-UGV coordination can provide real-world solutions that other types of coordination cannot offer. This paper systematically reviews the advances in UAV-UGV coordination systems during the period of 2015-2020 and offers a comprehensive investigation and analysis of the recent research. First, the essential elements in the UAV-UGV coordination systems are analyzed, and four key functional roles are identified. The close collaboration among functional roles can achieve the UAV-UGV coordination on perception, task, and motion. From the perspective of functional roles, UAV-UGV coordination systems can be further classified into eight categories. The functional-role-based category provides novel insights into analyzing various patterns of UAV-UGV coordination. This paper also discusses the challenges related to UAV-UGV coordination.