Autopilot fusion with external pilot inputs for enhancing flight safety of UAVs

This paper presents a method for fusing the control inputs of the external manual pilot with the autopilot commands to enhance the manual flight safety of UAVs (Unmanned Aerial Vehicles). The fusion restricts the pilot from taking the UAV into unrecoverable flight regimes by limiting the roll angles to certain limits while allowing full control authority if the UAV remains inside the limits. Outside the limits the robust adaptive autonomous control ensures the stability of the system. The scheme was tested in a high fidelity nonlinear hardware in the loop simulation for the King Saud University testbed UAV to show the effectiveness of the scheme.