Automated return-to-route maneuvers for unmanned aircraft systems

Motivated by the onboard pilots' responsibility and capability to safely return to a cleared route as soon as a resolution advisory is over, this paper first presents a simple framework to integrate a return-to-route system with a collision avoidance system, in which the automation problem for return-to-route maneuvers is formulated. A method, based on the Analytical Hierarchy Process for multi-criteria decision-making problems, is then proposed for this automation task. In order to evaluate its effectiveness, the proposed method along with a low-fidelity synthetic environment is modeled in Simulink^® for fast-time simulations. A simulation trial with 1606 encounter samples and three candidates is used to illustrate the exceptional encounters where an automation function may fail to return to the cleared route in a reasonable time. The simulation results show that the proposed method is able to handle these exceptional encounters.