FLIGHT TRAJECTORY CONTROL BASED ON REQUIRED RATE OF CHANGE IN FLYING DIRECTION FOR FIXED-WING UAVS

摘要

The paper proposes a flight trajectory control for fixed-wing UAVs of high maneuverabilityto a given (or desired) trajectory in the three-dimensional space. Inorder to let the UAV follow the desired trajectory, the controller determines a vectorof required rate of change in flying direction (RRCFD), which is perpendicularto that direction. The bank angle and the pitch rate command are then obtained tomeet the RRCFD and to avoid unnecessary rolling maneuvers. The features of theproposed control are as follows: 1) The position, the flying direction, and its rate ofchange of the UAV are all controlled closely to those of the desired trajectory, andlarge control errors, due to some disturbances or other, smoothly decrease towardzero. 2) The control system can incorporate any existing attitude and velocity controller,which makes the proposed control easy to apply. Numerical simulationsillustrate the effectiveness of the proposed control.