Research On UAV Delivery Flight Positioning Based On Beidou System

Terminal distribution is an important part in express business.This thesis,taking the application of UAV in terminal distribution as an opportunity,constructs an express system based on UAV,and analyses the role of each link in the system,highlights the roles of navigation positioning and path planning in the intelligent UAV delivery system,and then studies the navigation and path planning.Firstly,this thesis studies the use of China's autonomous satellite positioning system(Beidou navigation satellite positioning system)to solve the navigation and positioning problem in UAV delivery.This thesis studies the composition and evolution process of Beidou navigation satellite positioning system.In acccording to the principle of satellite positioning,analyzes the effects of satellite orbit,atomic clock accuracy,ionospheric delay and multipath effect on the positioning accuracy of Beidou navigation satellite,and measures the positioning accuracy of Beidou navigation satellite through Lab VIEW program.Analyzes the inadequacy of positioning accuracy in UAV delivery,then studies differential positioning to improve it.By introducing the principle of differential positioning and the methods of coordinate acquisition of reference station,and comparing the real-time measurement value,long-time average value and differential positioning value of measured points by experimental means,it is verified that differential positioning can significantly improve the positioning accuracy of Beidou satellite and meet the requirements of positioning accuracy of UAV delivery system.The hardware system is composed of positioner,serial port and computer.Through Lab VIEW programming platform,this thesis studies the software design method of calling Baidu Map by Lab VIEW and compiles the software.The software and hardware system for collecting and displaying positioning information is composed,it realizes the combination of abstract longitude and latitude information and specific map,and the more intuitive display of UAV flight position.Secondly,satellite navigation is an important part of UAV delivery flight positioning,but in order to achieve intelligent control of UAV delivery,it is necessary to plan the flight route of UAV.There are many kinds of planning algorithms,but the traditional planning algorithms will face new problems in the practical flight control field.This thesis improves the calculation process of A* algorithm by adding the restriction of turning angle and elevation angle to the extension of A* algorithm points,combining with UAV communication status,no-fly zones,terrains and other model settings,optimizes the planning time and shortens the path planning time.The simulation results of MATLAB show that the restriction of extended points improves the efficiency of path planning.