Comparison of 3D path-following algorithms for unmanned aerial vehicles

Unmanned Aerial Vehicle (UAV) development is a field with rising interest in recent years. One of its essential part is the autopilot, responsible for keeping the aircraft in desired flight conditions and for executing navigation tasks. Among the navigation tasks, one that stands out is the pathfollowing operation, which guarantees that the aircraft follows a predefined trajectory. The literature presents a variety of approaches with this function, based in geometric and control techniques; however, compared only for the 2D scenario. Therefore, the main purpose of this paper is to perform a comparison in the 3D scenario of the path-following algorithms Lookahead, Non-Linear Guidance Law (NLGL), Pure Pursuit and Line-of-Sight (PLOS) and Vector Field, regarding accuracy and computational cost. The simulation results of straight lines trajectories show that PLOS and Lookahead present lower errors and lower computational cost than NLGL and Vector Field, thus being more adequate.