Research On The Overall Design And Flight Control Technology Of A High Subsonic UAV

Turbine based combined-cycle(TBCC)is a research hotspot in the field of aviation.Based on the design of a low-speed TBCC combined dynamic flight test platform,this paper studies the overall design and flight control technology of a high-subsonic UAV..The main contents and achievements of this paper are as follows.Firstly,the overall aerodynamic layout of the UAV is determined according to the mission requirements of demonstrating safe and reliable low-speed takeoff and landing performance and high subsonic flight capability.In order to improve the aerodynamic efficiency and reduce the weight of the structure,the wing body fusion design is adopted.The shape of the wing is trapezoidal with no flat tail layout.In order to ensure good lateral stability,the double-vertical tail layout is adopted.Secondly,according to the known dynamic system parameters,the weight distribution of each subsystem and the maximum take-off weight of UAV are estimated.The feasible range of thrust-to-weight ratio and wing load was analyzed based on the constraint conditions such as designed cruising speed,take-off and landing runway length and stall speed,and the thrust-to-weight ratio and wing load of UAV were preliminarily estimated.CATIA is used to create the aerodynamic shape of UAV for CFD calculation,and the lift-drag characteristics and stability of UAV objects are analyzed according to aerodynamic calculation results.Thirdly,for the landing phase of the UAV,plan the landing trajectory and design the landing plan.Using the principle of total energy control,the longitudinal control law of landing is designed.The attitude inner loop adopts traditional PD control.The outer ring is used for speed and height control,which realizes the coordinated control of elevator and throttle.Realized accurate control of landing.Considering the uncertainties of the model,the key parameters of the UAV model are deflected.The simulation results of the parameter delamination show that the algorithm has certain robustness during the landing of the drone.Again,to improve the reliability of the flight control system,according to the principle of hardware reliability design,design UAV avionics system architecture.The redundancy of attitude sensor and actuator is designed.The selection and performance test of avionics are carried out.At the same time,the power supply demand of the whole machine is analyzed,and the power supply scheme is given.Finally,based on the flight simulation software FlightGear,the XML script file is used for secondary development,and the AC3D model for demonstration and verification of the drone is established to realize the real motion effects of the rudder surface,landing gear and other components.The visual display module of the model is created.Using UDP network communication mode and serial port communication mode,combined with FlightGear’s variable transmission protocol,realize FlightGear communication with flight control hardware and UAV dynamic model.Built a real-time semi-physical simulation platform for drones.