Research On Obstacle Avoidance Technology Of Plant Protection UAV Based On Millimeter Wave

In recent years,in the area of pest control,the application of "Plant protection UAV" have been used widely.But,the environment of farming is very complex and changeful,especially in the case of low visible moment.If people just rely on eyes observation to control the Plant protection UAV,there will be lots of limitations and much dangerous.So,the realization of Autonomous avoidance obstacles for Plant protection UAV,would improve the safety of operating it significantly.Thus,obstacle detection is one of the key issues in using of Plant protection UAV.the main works in this Paper as bellow:1.Millimeter-wave radar obstacle detection algorithm designThis Paper,took the advantage of characteristic which Millimeter-wave radar detect the echo center could be changed in the range of obstacle size,designed the obstacle detecting algorithm based on Millimeter-wave radar.This algorithm main included 4 parts:The front distance detection algorithm,the lateral distance detection algorithm,width detection algorithm and the obstacle hazard level ranking algorithm.2.Plant protection UAV flight system of avoidance obstacleThis system was mainly composed by self-designed obstacle detection sensor,main control module and plant protection UAV platform.Obstacle detection sensor was based on the deep integration of millimeter wave radar and STM32F745 embedded board;The plant protection UAV platform adopted the W730S multi-rotor plant protection UAV developed by Hangzhou Waobot technology.The main control module adopted AAEON’s pico-cv01 industrial computer.3.Design of obstacle avoidance flight software for plant protection UAVThis software was divided into two parts:obstacle detection sensor software design and main control module software design.The design part of obstacle detection sensor software analyzed the overall software flow,obstacle parameter extraction process,and the hazard level ranking process.The main control module software included parameter setting and self-checking software,it described using timer to control the time interval of obstacle detection and monitor the abnormal overtime,described the obstacle avoidance action parameters setting and software flow as well.4.Obstacle avoidance flight scene analysisThis paper analyzed the scene of interference to the obstacle detection on the ground(or plant crop top),the scene of large width of obstacle avoidance,the scene of blind area brought by obstacle avoidance sensor,and the scene of the most dangerous obstacle switching.5.Obstacle avoidance flight feasibility and error verificationIn this paper,Static and dynamic experiments were designed to verify the accuracy of obstacle detection and the effectiveness of the obstacle avoidance flight test system,the experiment result shows that:the front distance detection accuracy is±115mm,the lateral distance detection accuracy is±195mm,the width detection accuracy is ±235mm.And successfully implemented flying around the obstacle with avoidance,this prove the effectiveness of obstacle avoidance technology for plant protection UAV which based on Millimeter-wave radar.