Optimized Landing of Drones in the Context of Congested Air Traffic and Limited Vertiports

Drone fleet operators must be able to land the whole fleet in short notice. In practical operations, landing spots are usually much fewer than airborne drones. When many drones gravitate toward the limited landing spots simultaneously, congestion management becomes a challenge. This paper characterizes the fleet landing problem using mixed integer programming techniques and proposes a series of computational enhancements to reduce the solution time from hours to seconds. The solution algorithms are implemented in a software prototype for traffic management, and are thoroughly validated via extensive numerical examples and field simulations. For a fleet of 18 drones navigating at the same altitude layer within a 4-square kilometer area, all routing and trajectory computations can be completed in less than 5 seconds, and the entire fleet is able to complete landing at three pre-planned landing spots within about 3 minutes. Therefore, the models and algorithms are suitable for practical use.