Mixed Integer Nonlinear Programming for Aircraft Conflict Avoidance by Applying Velocity and Altitude Changes

The maneuvers of aircraft conflict avoidance are studied for air traffic management systems. In the scenario, aircraft are considered to operate flight within a shared airspace and cannot violate the minimum safe separation that they must keep in flight in order to avoid various possible conflicts. This paper proposes a formulation of the conflict avoidance problem as a mixed integer nonlinear programming (MINLP) with the maneuver that aircraft are allowed to change velocity and altitude to maintain the separation. Numerical experiments are performed to demonstrate the validity of the proposed MINLP model by comparison with the previous conflict avoidance model with only velocity change, and the illustration indicated a significant improvement in the efficiency of the conflict resolution as well as the magnitude of velocity variation. The optimal solutions of the problem are easily obtained by using global optimization solver in a shorter computational time even for large-scale aircraft.