Research On The Key Technology Of UAV’s Indoor Autonomous Positioning And Crossing Through Multiple Gates

With the rapid development of drone technology,drones can be used in search and rescue,aerial photography,transportation,and many other military and civilian fields.Due to its simple structure,the quadrotor has attracted widespread attention from scientific researchers.In many application scenarios,quadrotors need to perform autonomous navigation,autonomous obstacle avoidance and other tasks in a complex and challenging environment.UAVs autonomously traversing multiple gates has attracted more and more attention in UAV competitions at home and abroad,and they have been used as a competition subject to test the intelligence and autonomy of participating UAVs.The experimental scenario designed in this paper is as follows:The quadrotor needs to traverse 3 gates autonomously indoors,and a rotating obstacle is added in the middle of one of the gates,and the UAV needs to cross the rotating obstacle at a suitable speed.To complete the above design scenarios,the following three problems need to be studied and solved.This article first studies and solves the problem of estimating the position and attitude of the quadrotor in the room.In a GPS denied environment,the quadrotor needs to process the surrounding environment information through its own sensors to estimate its own pose information.In this paper,the binocular vision sensor is used to complete the real-time estimation of the UAV’s pose through the visual SLAM algorithm,and it is verified on the test data.Then study the control problem of UAV crossing multiple gates.Crossing the door gate involves the position control of the drone,and crossing the rotating obstacle involves the speed control of the drone.This paper first analyzes and establishes the kinematics model of the quadrotor,uses simplified strategies for the non-linear kinematics model of the quadrotor,and completes the position and attitude control of the quadrotor through the cascade PID controller,and completes the verification in experimental experiments.Finally,the target detection of the rectangular gate and the rotating obstacle is completed,and the position of the target relative to the UAV is calculated,and then the best crossing waypoint and crossing speed of the UAV are calculated.In this paper,the UAV platform is equipped with a monocular color camera,and a series of methods such as color feature extraction,video stabilization,noise reduction processing,morphological processing,contour screening and moving target detection are used to complete door frame target detection and rotating arm rotation angular velocity calculation,Quadcopter’s expected crossing waypoint and speed calculation,and complete the real experiment.After many experiments,the above-mentioned related algorithms used in this paper correspond to the designed experimental scene.The limit crossing time is about 44 seconds and the maximum angular velocity of the rotating arm that can be traversed is about 140 o/s.The autonomous traversing of multiple gates by drones involves multiple fields such as visual image processing,visual autonomous positioning,automatic drone control and so on.UAV has better intelligence and autonomy when facing complex environments,and can better complete tasks.