Aircraft Conflict Resolution with an Arrival Time Constraint

Abstract

A conflict resolution maneuver consists of two phases: avoidance and recovery. The goal of the avoidance maneuver is to increase the miss distance until it meets the separation standard, while the recovery maneuver seeks to merge with the nominal trajectory that was interrupted by the avoidance maneuver. Determination of the recovery maneuver can be non-trivial if there is an arrival time constraint at a downstream waypoint, because the conflict avoidance maneuver generally introduces a time delay. An analytical treatment of the integrated conflict resolution (avoidance plus recovery) problem has been developed, building on a Geometric Optimization approach for solving the conflict avoidance problem. A family of solutions for conflict resolution with an arrival time constraint has been generated and presented. Of particular interest is a special conflict avoidance solution, called the Delay Compensated solution. This solution avoids the conflict by blending a heading change with a speed change in such a way that the delay introduced by the path stretching is exactly cancelled out by the increased speed; hence the corresponding recovery maneuver is executed at the nominal speed. Unlike the standard speed and heading change avoidance solutions, which are often limited by aircraft performance, the Delay Compensated solutions remain feasible even for very demanding constraints on arrival time.