Design And Flight Control Of Hand-launched Fixed-wing UAV

Hand-launched fixed-wing UAV with the advantages of low cost,portability and high mobility have played an increasingly important role.Besides,disturbance from hand throwing is quite inevitable,and it is a big challenge to achieve stable flight control.Thus,we designed a hand-launched fixed-wing unmanned aerial vehicle(UAV)with high performance in portability,lightweight and maneuverability,established UAV dynamics model,developed the flight control system,and realizes the smooth hand-launched flight.The main research work of this paper is as follows:In view of the low take-off speed of the hand-launched UAV when it is thrown,the UAV is required to be lighter in weight and larger in thrust.The overall design requirements,aerodynamic layout,power system and wing type are determined.The lift-drag aerodynamic characteristics of airfoil and wing are calculated using simulation software.Based on the modular design idea,the structural design of wing,fuselage and nose,tail beam and tail fin is completed,forming the overall structure diagram.Taking the designed hand-launched fixed-wing UAV as the research object,the dynamic model of the UAV system is established,and the gravity,aerodynamic force,thrust with their related torque are deduced,and the kinetic equations of the system are obtained.On this basis,the simulation model of system dynamic is built,and the flight dynamic characteristics of the UAV are revealed,which laid the foundation for the design of the control system and the analysis of dynamic characteristics of the UAV.Aiming at the complex problems such as large disturbance in the hand-launched process and multi-loop motion coupling control,a system-decomposition-based robust control method is proposed to reduce the control complexity of the UAV system by decomposing the complex flight system into a group of simple subsystems with disturbances:roll-yaw subsystem,pitch-altitude subsystem and airspeed subsystem;Besides,to improve the tracking performance and robustness to disturbances,an extended state observer(ESO)based robust control method is proposed for each subsystem.Finally,a simulation platform for hand-launched UAV is built,and the influence of different initial speed and initial attitudes of the UAV on the take-off process is analyzed,which provides theoretical guidance for the hand-launched take-off of the UAV.The performance of the designed UAV and control system is verified by actual hardware equipment.Flight experiments show that the UAV can achieve stable hand-launched flight,route flight,dive pull up guidance and glide landing under wind disturbance.The cruising speed of the UAV is 70km/h,the maximum flight speed can reach 100km/h,and the maximum flight altitude is more than 300 m.Figures 54,tables 11,references 81...