The Research Of UAV Fast-Landing Control Technology

The landing process of the UAV is the most complex and pivotal stage of the flying process,it is necessary to ensure the safety and high accuracy,so the UAV landing control technology becomes a pivotal technology and research keynote of the UAV flight control field;many advanced landing control technologies have come out.This paper presents a kind of fast landing control technology which based on the steep gliding angle under this background.The fast landing mode has the superiorities of shorter landing distance and time and it also has a higher landing accuracy when compared to the usual landing mode that based on the shallow gliding angle.In this paper,after the UAV six freedom models is established according to the aerodynamics and Newton kinematics theory of rigid body first,then the pneumatic performances,maneuver performances,control performances and modality performances are researched.The track line is divided according to the analysis results of the UAV performances,including steep gliding fast pulling-up and ending gliding track line,and then the design results are given.According to the quests of the 3D track line,the longitudinal controller with C* controller as inner loop,height and height rate controller as outer loop are designed by using robust servo,L1 adaptive theory and classic control theory,they realize the accurate tracking of the height profile.Then the controller whose inner lop is roll angle controller and outer loop is cornering controller is designed to realize the accurate tracking of the track line,the safety and accuracy are also ensured.To evaluate the robustness of the controller,the robustness of control system is evaluated by using the multivariable system evaluating method which based on the system return difference matrix and inverse return difference matrix minimum singular value.The results show that the controllers which designed in the paper have good robustness and meet the quest of UAV fast landing.Finally,the fast landing system is established by using the MATLAB/Simulink block,the integrated simulations of standard state,parameter uncertainty and atmosphere disturbance is completed under the nonlinear environment.The results show that the control system can guide the UAV landing safety with high landing accuracy when the UAV is disturbed.