Design And Experimental Research Of Long-endurance And Light Remote Sensing Fixed-wing UAV

Recently,aviation equipment and sensor technologies have continuously developed and optimized.Low-altitude remote sensing with UAV has been applied to a variety of fields in military and civilian use due to its advantages such as high spatial resolution,low cost,and high efficiency.It has become an intelligent unmanned system for human beings to perceive complex environmental factors with unlimited potential and promising research value.At present,small remote sensing drone is still restricted by endurance and flight control system.A long-endurance battery-powered light flying-wing UAV was developed for remote sensing in this research from the practical application perspective,which aimed to improve the endurance when carrying fixed load,and provide some reference and theoretical foundation for the design and control strategy research of small fixed-wing UAVs.The main research contents of this paper are as follows:1.The layout form and structural parameters of the UAV were designed based on the design index and performance requirements.The physical model of the drone was established.The parameters of the winglet type and the sweep angle were optimized through comprehensive tests.CFD（Computational fluid dynamics）was utilized to obtain the aerodynamic characteristics and theoretical endurance time.ANSYS was employed to acquire the force distribution in cruise state.The simulation results indicate that the structure,material,and performance of the UAV are suitable for remote sensing.2.The force model,dynamics and kinematics model of the UAV were derived.The aerodynamic coefficients were gained based on CFD simulations.The parameters of the propulsion system components（motor,servo motor,battery,and propeller）were identified by experimental tests.The simulation model,environment model and visualization model were established based on Simulink and then differences between linear model and nonlinear model were analyzed.3.The overall control strategy of the drone was presented.The stability controller was established based on cascade PID method and the parameters were tuned.On the basis of the stability controller,the path following controller and path management controller were designed by vector field guidance law and L1 guidance law.The simulation results indicate that the designed controllers have exciting performance and robustness under turbulent conditions.4.The PX4-based flight control system was developed,and the peripheral avionic devices and remote sensing system based on Pixhawk were established.The attitude control,altitude control,yaw angle control and flight endurance of the UAV were verified by flight tests.The test results indicate that the flight control design methods are stable and effective.The controller can meet the functional requirements of flight control and remote sensing of the UAV,which verifies the effectiveness of the control strategy.