3D Obstacle Avoidance System Using Ellipsoid Geometry

This paper presents the development of a 3D obstacle avoidance algorithm for Unmanned Aerial Vehicle (UAV) system. The avoidance algorithm works by generating avoiding waypoints, within the original predefined waypoints, when the vehicle faces obstacles obstructing its flightpath. The proposed approach bases its algorithm on the utilization of ellipsoid geometry for defining a restricted zone containing the obstacle. Once the restricted ellipsoid zone has already been established, the algorithm computes the locations of new waypoints on the edge of the ellipsoid. These new waypoints represent the contact points between the ellipsoid and planes the normal vector of which are determined form the vehicle velocity vector. The geometry and dimension of the ellipsoid are determined using the known information about the size of obstacle which is assumed to be available, either from mission database or predicted from UAV's ground detection system. At this stage, the algorithm computation is implemented in MATLAB environment and then evaluated for a couple of cases representing some situations when an UAV has to avoid obstacles during its flight to a predefined destination. This algorithm then can be integrated into a waypoint following system and/or guidance system of UAV.