Trajectory Optimization And Control Of Perching Maneuvers For Morphing Aircraft

Perching maneuvers is inspired by the landing process of birds in nature.Aircraft pull up the angle of attack(AOA)quickly to produce high drag to decelerate rapidly and finally achieving landing accurately.There is a problem of conventional perching maneuver that elevator is in low aerodynamic efficiency and can’t control the attitude efficiently due to the low speed and high AOA in the later phase.Therefor we manufacture a UAV which can change the position of wing to aid perching maneuver.Modeling and trajectory optimization of the morphing UAV’s longitudinal motion was studied in this paper.Firstly,the indoor flight experiment was carried out,and the flight data was obtained by the motion capture system.Based on the experimental data and flat plate theory of aerodynamic,the aerodynamic model of morphing UAV is built.Based on this,the longitudinal dynamic model is built.Secondly,using GPOPS optimization tool to design the trajectory of the UAV model.The optimization results show that,compared with conventional fixed wing UAVs,variant parts can significantly improve the UAV attitude control efficiency and maneuverability.According to this,a time-varying optimal controller is designed to track the optimal trajectory of the aircraft.The simulation results show that the aircraft can track the trajectory effectively when it deviates from the initial position moderately.Lastly,the indoor flight experiment platform is built,and a closed-loop control system is designed included the hardware and software architecture.The experimental results show that the closed-loop control can land more precisely than the open-loop,at the same time the variant components can control the aircraft’s attitude effectively.