Development of Sliding-Mode Landing Controller using Cooperative Relative Localization with Pattern Generation

In this paper, we develop a landing controller based on sliding-mode control law for landing a UAV on a moving ship using relative estimates in GPS-denied environments with range-only measurements. Precise knowledge of relative position, orientation and velocity is required to accurately land an Unmanned Aerial Vehicle (UAV) onto the surface of a moving platform. Although vision-based techniques have been used to previously solve such problems, they fail in dark or hostile weather conditions and also a line of sight is required with the landing platform at all times. Cooperation among different Unmanned Vehicles (UVs) have been introduced to aid the estimation process. We also investigate how different trajectories followed by supporting vehicles effect the localization accuracy. A Matlab/Simulink simulator has been created and exhaustive simulations have been performed that demonstrates the effect of these trajectories on localization accuracy.