Autonomous unmanned aircraft collision avoidance system based on geometric intersection

Abstract

Autonomous Unmanned Aerial Vehicles (UAVs) are envisioned as an integral part of future urban civil and military applications. Large and small scale UAVs will perform large variety of autonomous tasks. However, the capability of UAVs to navigate completely autonomous in real environment is still in its infancy. Autonomous collision avoidance is a necessary step toward this goal. This paper introduces a new collision avoidance approach based on geometrical intersection method for the estimation of collision risk. The approach forms the last line of defense against air-to-air collisions. When a UAV encounters other aircraft that is estimated to approach closer than the minimum safety margin, the resolution unit will be activated in which the direction commands of each UAV in a conflict will be generated, leading to cooperative maneuvering. UAVs flying in a shared airspace are assumed to be linked by real time data bases to share the information of each other and to send and receive the commanded trajectory maneuvering to apply. The proposed approach acts as a control command filter that issues the safest turn and altitude commands, based on collision potential metric, taking into account the minimum possible flight plan change among the solution set.