Reachability-Based Safety and Goal Satisfaction of Unmanned Aerial Platoons on Air Highways
For UAV traffic management, this work provides a structured approach to guarantee safety and goal satisfaction in large multi-agent systems, though it is incremental as it combines existing methods (fast marching, Hamilton-Jacobi reachability) in a new application context.
The paper proposes organizing UAVs into platoons on air highways to enable tractable safety and goal satisfaction guarantees. Using Hamilton-Jacobi reachability, they guarantee safety for one breach per vehicle per altitude range, and demonstrate the concept in simulations.
Recently, there has been immense interest in using unmanned aerial vehicles (UAVs) for civilian operations. As a result, unmanned aerial systems traffic management is needed to ensure the safety and goal satisfaction of potentially thousands of UAVs flying simultaneously. Currently, the analysis of large multi-agent systems cannot tractably provide these guarantees if the agents' set of maneuvers is unrestricted. In this paper, platoons of UAVs flying on air highways is proposed to impose an airspace structure that allows for tractable analysis. For the air highway placement problem, the fast marching method is used to produce a sequence of air highways that minimizes the cost of flying from an origin to any destination. The placement of air highways can be updated in real-time to accommodate sudden airspace changes. Within platoons traveling on air highways, each vehicle is modeled as a hybrid system. Using Hamilton-Jacobi reachability, safety and goal satisfaction are guaranteed for all mode transitions. For a single altitude range, the proposed approach guarantees safety for one safety breach per vehicle, in the unlikely event of multiple safety breaches, safety can be guaranteed over multiple altitude ranges. We demonstrate the platooning concept through simulations of three representative scenarios.