Design And Implementation Of UAV Landing Control System Based On PX4

With the rapid development of drone technology,drones have become closely related to people’s lives.As an excellent open source flight control software,PX4 has also developed drones based on it.With the rapid development of artificial intelligence,computer vision and microcomputers,people have increasingly higher requirements for the accuracy and intelligence of drones.At present,most domestic drone landing technologies use the GPS positioning method.The path planning is to manually set a series of path points,and there is poor landing accuracy(the GPS landing accuracy is generally around 5m).Manually setting path points is cumbersome and flying Control hardware has the disadvantage of poor computing performance.In order to solve the above problems,this paper designs a PX4-based drone takeoff and landing control system software based on computer vision to locate and land,and automatically generates paths based on the graph structure.This software runs on an onboard computer and communicates with the pixhawk2.1 platform equipped with flight control software PX4.This paper first analyzes the needs of the PX4 based UAV landing control system functions,mainly introduces the communication function based on MAVLink protocol,visual positioning function,landing logic function and path transmission function.The communication functions based on the MAVLlink protocol mainly include an on-board computer to read messages and an on-board computer to send messages.The visual positioning function mainly includes a configuration camera function,an image processing and recognition function,a distance calculation function,and a coordinate calculation function.The landing logic function mainly includes the landing logic design for target detection failure and the landing logic design for successful target detection.The path sending function includes an on-board computer switching flight control flight mode function and an on-board computer sending path function to the flight control.According to the needs analysis,this paper adopts a modular approach to the overall and detailed design of the PX4 UAV landing control system software.This software includes detailed design and implementation of communication module based on MAVLlink protocol,vision positioning module,landing logic module and path sending module.Finally,the functions and performance of communication based on MAVLlink protocol,visual positioning module,landing logic module and path sending module are tested respectively.The test results show that the PX4 drone takeoff and landing control system designed in this paper can make the UAV carry out the flight mission according to the path sent by the onboard computer,and the visual positioning method is used to make the UAV accurately land on the target board when landing.