Design And Research Of Autonomous Take-off And Landing Aircraft And Polar Ice-based Buoy Landing Platform

In recent years,major countries in the world have strengthened their research on polar expedition equipment,and the corresponding monitoring technology has also developed rapidly.However,most of the monitoring methods are still based on remote sensing satellites,which obtain large-scale polar ocean,sea ice,and ice and snow data,and there is a lack of environmental data for small-scale on-site fixed-point observations.Since most of our country's scientific research activities in the polar regions are carried out in the summer,and the scope of personnel activities is also restricted by geographical factors,long-term and large-scale monitoring of the polar environment cannot be carried out.With the improvement of the intelligent degree of small aircraft,it is widely used in all walks of life.In polar scientific research,the application of UAV is more and more,and researchers often use it to take polar environment images.Therefore,it is very promising to design an automatic integrated buoy which can control the UAV to measure the air environment data within 10 meters(low altitude)under the condition of unmanned monitoring,and can simultaneously measure the parameters of ice,snow depth or sea water.This project designs and develops a sea ice buoy for UAV.The buoy is equipped with an UAV equipped with environmental detection sensors.When the weather meets the flight conditions,the UAV flies out of the buoy to detect environmental data such as temperature,humidity,wind speed and direction at a certain height.After the measurement,the UAV flies back and lands in the buoy,and the charging device is configured in the buoy to supplement power for the UAV.The buoy is equipped with various kinds of sensors,and the lower part of the buoy is equipped with sensors for the underwater marine environment,which can measure the seawater temperature,salinity,chlorophyll concentration,oxygen saturation and other parameters.As the buoy drifts with the sea ice,it is difficult for the UAV to land on the moving buoy from autonomous takeoff to the end of detection.In view of this problem,this paper uses the autonomous landing method of mobile target based on visual navigation to solve the problem.The main work of this paper is as follows:Firstly,for the X-shaped quadrotor aircraft carried by the buoy,the power system of the UAV is designed,and the mathematical model of the UAV is established.The overall design of sea ice buoy,hardware design of UAV,hardware design of flight control system and visual navigation system are completed.Then,the Apriltag code is selected as a specific landing marker,the target recognition and tracking positioning algorithm is studied,the camera modeling is carried out,the relative pose between the camera and the landing marker is obtained through the PnP equation,and the CMT algorithm is proposed to optimize the image processing process.The attitude controller and position controller of UAV are designed by PID control.The simulation results show that the PID control system has fast response and no static error.The autonomous landing mode assisted by unmanned ground station is selected,and the autonomous landing strategy of UAV is formulated accordingly.Finally,the simulation tests of the whole system are carried out in the simulation software,and the real landing experiments of the moving target are carried out in the indoor and outdoor.Through the simulation and experiment,we can get the conclusion: For moving targets,it only takes 50 seconds for UAV to land from the altitude of 10 m,and the landing accuracy can reach ± 0.25 m.The visual navigation autonomous landing system designed is reasonable and feasible,and the stability and real-time performance meet the requirements.