VTOL Control of Tailsitter UAV Under Crosswind Disturbances

To solve the problem of crosswind disturbances and thrust boundedness for tailsitter vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) control, this paper presents a control method by taking advantage of the aircraft's rolling freedom to decrease the crosswind disturbances and relax the restriction on maximum thrust. First, a mathematical model was constructed to illustrate the relationship of wind direction, aircraft attitude and disturbance force. Next, a new attitude extraction algorithm using wind direction was designed based on the traditional backstepping control method. And the control input was limited by saturated function method to solve the problem of thrust boundedness. Finally, a position controller for tailsitter aircraft was designed with simulation showing its effectiveness.