Optimization and Trajectory Tracking of Deep Stall Landing for a Variable Forward-swept Wing UAV

This paper presents a trajectory optimization and robust trajectory tracking of deep stall landing for a variable forward-swept wing unmanned aerial vehicle (UAV). Firstly, the longitudinal dynamics model of a variable forward-swept wing UAV is established, and the aerodynamic parameters in a wide-range angle of attack (AOA) are obtained using computational fluid dynamics (CFD). Then, considering multiple running and terminal constraints of UAV deep stall landing, Radau pseudo spectrum method is adopted to generate optimal landing trajectory. Furthermore, to cope with the nonlinear and uncertain aerodynamic parameter at high AOA, a robust trajectory tracking controller is designed via combining feedback linearization and extended state observer (ESO). Finally, nonlinear numerical simulation is conducted to verify the proposed method. The simulation results demonstrate that the control accuracy of the designed controller under various disturbances can meet the landing requirements.