Experimental Study On Main Spray Performance Of Single Rotor Plant Protection UAV

The operation efficiency and reliability of plant protection Unmanned Aerial Vehicle(UAV)can be improved effectively.Because of its high distance from crops during ope ration,droplet deposition is affected by the interaction of air flow and external wind in the rotor rotor.According to the problem of unstable working width caused by wind field during application of UAV,the optimal structure layout of UAV spraying is determined,the theoretical simulation and simulation analysis are combined by CFD method,and the test bench which can be used for indoor droplet collection is designed.the effect of product uniformity,establish a regression model between the parameters and the effective spray amplitude,and determine the optimal parameter combination suitable for LTH-100 single rotor UAV operations.In order to lay the foundation for the research of the wind field below the UAV,and provide help and guidance for the single rotor UAV nozzle configuration and operation route planning.The main research contents are as follows:(1)Test of nozzle spacing in front,middle and rear position and Y direction of spray rod in X direction,respectively,determine the optimal spray rod position and nozzle spacing according to droplet deposition,deposition uniformity and deposition density,and lay the foundation for effective spray amplitude study;By judging the droplet trajectory,calculating the horizontal displacement of droplet under the wind field to obtain the theo retical width of effective spray amplitude,selecting Solidworks software to establish the physical model of single rotor plant protection UAV,simulating the wind field under the rotor,exploring the influence law of parameter change on wind field and effective spray amplitude,and determining the main influencing factors of effective spray amplitude under wind field.To provide the basis for the study of effective spray amplitude;(2)Design the test bed which can be used for indoor droplet collection,use droplet density determination method to evaluate the effective spray amplitude,select a device which can be applied to indoor simulated UAV flight state for droplet collection.By placing the speed-regulating conveyor under the lift able UAV test-bed for droplet collection,the test-bed can achieve 2.0m~4.0m lifting,and the adjustable speed range of speed-re gulating conveyor is 2.0-6.0m/s;(3)Based on the study of the theoretical width of the effective spray amplitude,the flight altitude,flight velocity,lateral wind angle and external wind speed were selected as the test factors,and the indoor and outdoor multi-factor tests were carried out with the effective spray amplitude and droplet deposition uniformity as the test evaluation indexes 6.0m/s,UAV When the flight speed is 2.0m/s,effective spraying 7.5m for single rot or UAV.The results show that under the premise of satisfying the operational efficiency of UAV,the operation under this parameter can spray amplitude and droplet deposition uniformity,and can provide guidance for the actual trajectory planning of UAV.