Collision Avoidance System for Unmanned Aerial Vehicle (UAV)

Abstract

A collision avoidance flight guidance and control is developed to be implemented in a small UAV system. The obstacle avoidance system is designed to be an integral part of the autonomous flight control system, such that the UAV has ability to manage its maneuvers and flight trajectory during particular missions. The avoidance system has to be able to adjust the flight path in case potential collision with other flying vehicles is detected. The algorithm principally works by compute new waypoints at each time step for correcting the original ones. In the proposed approach, once a potential flight path conflict (collision) is detected, an ellipsoid zone is attributed to the conflicting vehicle. Then the UAV system will compute new trajectory avoiding the conflicting flight path by determining contact points on the boundary of the moving ellipsoid at each particular time steps. The contact points computation considers the relative positions and velocity vectors between the UAV and the conflicted fying vehicle. Based on the obtained avoiding waypoints, a flight guidance and a flight control systems are designed to steer the UAV following the suggested path. The controller principally works by driving the cross-track and course angle errors of the UAV flight, relative to the desired path, to zero, through performing Bank to Turn (BTT) maneuvers. The system generates corrective commands, based on the error information, and transforms it into a heading change via roll maneuver. The roll maneuver controller is designed using LQR technique such that it can provide an appropriate roll dynamics of the UAV. Simulation results will be presented and analyzed to investigate the performance of the proposed system.