Research And Design Of A Fixed-point Autonomous Landing System For A Four-rotor Aircraft

The application of UAV is very promising,and there are many problems need to be solved.In this paper,the qundrotor as a representative of UAVs.And a auxiliary landing system is studied and devised.Firstly,the paper studies the global satellite navigation system,analyzes its error,and proposes a "relative positioning" method to make the positioning accuracy within2 meters.In order to make the positioning more accurate,we also use visual position and design a visual position target.There are three states of this target that can be applied to different lighting conditions.According to the characteristics of the target,a specific algorithm is designed,which makes the target can be accurately identified under the conditions of sufficient light in the daytime or low light at night.Then the four-rotor aircraft is analyzed and modeled.According to the theoretical guidance,build a four-rotor aircraft based on "Pixhawk",which is open source flight controller.In addition,the ground control system of the four rotor vehicle is designed to control the qundrotor auto land.Finally,the whole platform is tested.The test results show that the system designed in this paper can make the autonomous landing accuracy of UAV reach within 0.5m.