Study On Approach Radar Guides Unmanned Aerial Vehicle Autonomous Landing Simulation

Approach radar guides the UAV autonomous landing is one of the main UAV landing ways, due to the approach radar to guides the UAV autonomous landing in the guiding process, only measure the UAV’s position parameters in the air, but can not measure the flight attitude, and UAV’s posture during landing process and touch earth, also the vertical velocity are critical to the safety of the UAV autonomous landing, Based on the approach radar guides the UAV autonomous landing process simulation, and analysis of the simulation results, study on the variation of the UAV flight parameters in the autonomous landing process to improve UAV autonomous landing’s safety and accuracy, the contents as follow.First analysis of UAV autonomous landing process, the main process includes level flight segment, down segment, leveled segment, and to analyze the aerodynamic characteristics of the various stages, summarizes the calculation of aerodynamic forces and moments calculated formula and aerodynamic coefficients, the composition and meaning of pneumatic torque coefficient, analyzed and finishing UAV’s structural parameters and aerodynamic parameters that are used in simulation calculations, getting completely UAV’s data for simulating.Second established a complete nonlinear mathematical model of UAV six degrees of freedom, and describe common coordinate system and the coordinate transformation equations of motion were introduced. Determined the calculation method for solving nonlinear equations of motion of the UAV that is standard of fourth-order Runge-Kutta method, analyzed and verified the reliability and accuracy of the method. Longitudinal control of the UAV and lateral control were analyzed, designed UAV longitudinal and lateral control loop, through Matlab/Simulink simulation modeling verifying the accuracy of the designed control system and the calculation method’s reliable used in simulation.Then by calculating gets the UAV’s initial parameters, simulating and analyzing radar guides UAV autonomous landing, obtained the UAV’s pitch angle, pitch angular velocity, angle of attack, vertical speed, flight path’s changed rule in landing, and detailed analysis the variation to identify the position of the mutation and the maximum amount of change in these parameters.Finally, obtained a UAV’s autonomous landing performance including flight, landing time, vertical speed, touchdown attitude and determine the landing process’s dangerous position through analyzing of approach guiding radar guides UAV autonomous landing.