2 1/2 D conflict resolution maneuvers for ATMS

This work is motivated by the current trend in the aviation community to move towards decentralized air traffic management systems (ATMS), in which the aircraft operate in "free flight" mode instead of following prespecified "freeways in the sky". Automatic conflict resolution strategies are an integral part of the free flight setting. Given the nature of the problem, the limited sensing capabilities, and the complex aircraft dynamics and constraints, it is very hard to solve the conflict resolution problem in its full generality. Indeed, the appropriate solution should be safe (collisions never occur), live (destinations are always reached), and flyable (dynamic constraints on accelerations and velocities are satisfied). This paper explores the use of distributed motion planning for multiple aircraft using vector field techniques. The coordination between aircraft is achieved using a series of horizontal and vertical planar avoidance maneuvers, resulting in 2 1/2 D solutions. The switching nature of the proposed solution makes it natural to model and analyze the resolution protocols using hybrid systems techniques.