Application Of Millimeter Wave In Obstacle Avoidance Of Plant Protection UAV

With the rapid development of industrialization and informatization,UAV is more and more prevalent used in agricultural development.However,our country has a vast territory and complex geographic environment,so it is very limited to rely on pilots to control UAV to achieve plant protection operations,and it is prone to crash risks.Therefore,in order to better serve agriculture,improve the efficiency of plant protection operations,and reduce the difficulties of ground personnel,it is necessary to use obstacle avoidance technology on plant protection drones.The technology of autonomous obstacle avoidance is of great significance to plant protection drones and personnel safety.The main work of this paper:(1)Design of algorithm for detecting obstacles by millimeter waveAiming at the problem of UAV obstacle avoidance,this paper uses millimeter wave Doppler frequency shift characteristics to detect the change of the return waveform on obstacles and designs an obstacle detection algorithm based on millimeter waves.The algorithm calculates the data mainly according to the relative distance and angle between radar and obstacle.It mainly includes the horizontal distance detection algorithm,the longitudinal distance detection algorithm,the obstacle width detection algorithm,the danger sorting detection algorithm,and the obstacle avoidance strategy of the obstacle avoidance algorithm in the millimeter wave radar.The flight scenes of various obstacles encountered by the plant protection UAV in farmland are analyzed in detail by these algorithms and given flight scenarios in different obstacle scenarios,so that the plant protection drone can deal with most of the obstacles in the farmland and ensure the stability and safety of plant protection operations.(2)Design of the Barrier Protection System for the Plant Protection UAVThe obstacle avoidance system of plant protection UAV is consisting of millimeter wave radar hardware design and millimeter wave radar software design.The hardware design of millimeter-wave radar for the desired experimental target,the millimeter-wave radar components are selected.The operational control module,power module and storage module of radar are designed,and the corresponding circuit schematic diagram is formulated,and the data transmission protocol is formulated.The millimeter wave radar software design contains the module host computer software design and the obstacle avoidance algorithm software design.The upper computer software design part includes the maximum minimum detection distance setting,sensitivity setting,transmission protocol,etc.The software design part of the obstacle avoidance algorithm analyzes the overall software process,obstacle parameter extraction,analysis and application,and hazard ranking.(3)Experimental results and error analysisThe feasibility of the obstacle avoidance algorithm and the safety of plant protection operations were verified in static and dynamic scenarios.The transverse distance detection algorithm,longitudinal distance detection algorithm and obstacle width detection algorithm are experimented,respectively.The experimental results show that the obstacle detection algorithm designed in this paper can achieve the actual operation requirements and expected goals,accurately detect obstacles,and plan new routes to avoid obstacles and fly around.Prove the feasibility of millimeter wave in the application of obstacle avoidance in plant protection drones.