| Aviation plant protection technology occupies a prominent position in modern intelligent big agriculture due to its flexible and convenient flight operations and high operation efficiency.However,problems such as drift and deposition effects are still not obvious in the operation process.Therefore,this article takes the drone structure as the entry point,and on the premise of meeting the standards for plant protection equipment spraying,theoretically analyzes the deposition relationship of the droplets through the wind field distribution of the drone.Based on computer fluid dynamics,the wind field under the drone's rotor is simulated and analyzed.In this wind field,the influence of the rotor field of the quadrotor plant protection UAV on the droplet deposition effect under different operating parameters was studied to obtain the optimal operating parameters for spraying effects.It lays the foundation for optimizing the spraying of multi-rotor drones,improves the deposition effect of fog droplets on the surface of crops,and provides support for the research of precise application technology.The main research contents are as follows:(1)Theoretical analysis and simulation of spray deposition on rotor wind field distribution.The aerodynamics theory is used to analyze the formation characteristics of UAV wind field and the change law of wind field speed.Combined with the characteristics of wind field,further analyze the settlement process of fog droplets in the air flow field,and clarify the wind field under the rotor and other different effects The change law under force provides theoretical support for analyzing the distribution law of rotor wind field based on CFD numerical simulation.Based on the theory,using the Solidworks Flow Simulation fluid dynamics simulation sub-module software,the finite element analysis and design of the four,six,and eight rotor UAVs are performed.The wind field below the rotors is simulated,and a multi-rotor plant protection drone is established.The relationship between the numerical simulation function of the wind field and the number of rotors and the wheelbase provides a model basis for the droplet deposition effect under the wind field.(2)Design and Research of Multi-rotor Plant Protection UAV Test Bench.According to the simulation results of simulated drone rotors and the test results of the droplet deposition effect,a visualized multi-rotor plant protection drone test platform wasdesigned.The test bed can realize the control and monitoring of different operating parameters of the drone,ensuring the drone.Altitude,rotor speed,and pressure can be monitored to achieve a high degree of coordination between pesticide spraying,droplet collection,and droplet deposition effect detection during plant protection operations;after the test,the test platform can perform remote control and real-time processing and storage of test data.(3)Verification of wind field distribution based on test bench and experimental research on the effect of mist droplet deposition.Based on the simulation results of the rotor drone,a three-factor multi-level mixed-horizon orthogonal test design was carried out,and a four-rotor plant protection drone was subjected to a wind quantification test,a mechanical performance test,and a spray operation test.Factors such as flight altitude,rotor speed,and rotor wheelbase have a significant effect on the evaluation index of droplet deposition,affecting the primary and secondary order: rotor speed>rotor wheelbase> flight height.When the four-rotor plant protection UAV operating parameter combination is: flight height is 1.5m,rotor speed is 2000 r / min,and rotor pitch is 610 mm,after the spray test is performed,the evaluation index of the droplet is: deposition amount 1370 ml,coefficient of variation is 40.1%,The drift rate is 15.8%,and the spraying effect is the best at this time. |
PDF Full Text Request