A Vision-based Guidance System For UAV Autonomous Landing Using Line Extraction Of Runway

Autonomous landing and recovery of UAV is an important link in the development,production and operation of UAV.It is the most dangerous and complex phase of flight.The vision-based navigate has many advantages such as passive measurement,low cost,high accuracy,and anti-interference.It has been paid more and more attention in recent years.The commonly typical Pn P algorithm need accurate point cooperation marks,which extraction accuracy and robustness are low.So difficulties in application.Runway and runway plane line features are the most significant and reliable features,so the study of the position and attitude estimation algorithm based on runway features and runway plane features have practical value and wide application prospect.So this paper studies the Core technology of the vision-based landing method using the feature of runway for UAV,and has done a lot of experiments on the engineering application.1.A new algorithm based on LSD(Line Segment Detector)algorithm is proposed,which is based on the characteristics of runway edge feature and runway plan feature.In this method,the LSD algorithm is the core,and the geometric and gray features of runway features are combined to establish the recognition model.The robustness and practicality of the method has been proven by experimental results.2.Because of the real-time requirements of pose measurement,the feature tracking method based on one dimension method is proposed for the linear features.In a large number of experiments,the method is proved to have the advantages of small calculation,strong adaptability and tracking stability.3.This paper further studies the pose estimation method based on the position and pose estimation method:For the estimation problem of pose and attitude of fixed-wing UAVs in the terminal landing stage,two landing method using different features is proposed.Based on the structured line features of runway,the all method using runway edge and a single vertical to the edge of the cooperation symbol line constitutes a with parallel and perpendicular,location known structured line configuration,to calculate the UAV to all parts of the pose parameters(yaw,pitch angle,roll angle,vertical distance,horizontal distance and height).4.Based on the runway edge line features,part method,which using only runway edge to calculate the four important pose parameters(yaw,pitch angle,lateral offset and height).5.The experiment system of UAV Ground assistant ground verification is designed,and the experimental platform is built.The experimental results are simulated and the landing process is simulated.The accuracy of this method is verified.6.According to the actual needs,this method has been validated by three-dimensional visual simulation system.It can validate the accuracy of this method and test the real-time performance.