Study On Plant Variables UAV Variable Spraying System

In recent years,drones have become more and more widely used in the field of plant protection.Agricultural plant protection UAVs have more significant advantages in terms of convenience and spray efficiency.At present,most drone spraying systems use quantitative spraying,and the uniformity of spraying needs to be improved.Therefore,the key principles and techniques involved in variable spraying are studied in detail in this paper.The main tasks of this article are:(1)Variable Sprinkler System Algorithm DesignIn order to achieve automatic automatic regulation of spray flow for the purpose of focusing on the relationship between aircraft flight speed and spray flow.According to the influence of speed on spray uniformity,a control algorithm to improve spray uniformity of plant protection UAV was proposed.The algorithm decides whether to use the PID or the integral PD flow control algorithm by judging the threshold to improve the coverage of the variable system and adjust the parameters by ZN method.(2)variable spraying system hardware and software platform designIn order to improve the performance of the agricultural plant protection UAV spraying system,the hardware core embedded board of the spraying system is designed.The components of the centrifugal spray head,water pump,flowmeter and electronic governor are used to form the variable spraying system of the plant protection UAV to complete the experimental platform Hardware building work.The software design of the variable spraying system is divided into four parts,namely,the self-checking part before flying,obtaining the speed part,the flowmeter collecting part and the pulse width modulation part.Pre-flight self-test Responsible for the detection of the entire spray system in the sub-function module before take-off in the running state.Multithreading and software timers are used to ensure real-time acquisition of real-time aircraft speed and flow meters.The pulse width modulation program outputs the pulse width modulation signals of different duty cycles to adjust the spray flow of the centrifugal nozzle.And completed the spray settings software interface and functional design.For different crops need different spraying indicators to write the spray parameter setting software to solve the problem of the manual gear shifting of the splitter-type plant protection UAV.(3)Variable spray feasibility and coverage verification testFrom 0m/s to 5m/s drone flight speed,a verification experiment of the variable spray system was designed.The effect of the spraying operation was analyzed by the droplet image information of the water sensitive paper.The experimental results showed that the coverage rate of the plant protection drone spray adjusted by the flow PID increased as the speed increased from 0 m/s to 5 m/s.Between 27.81% and 32.86%;the spray system designed for this study meets the requirements for ultra-low volume spraying.At the same time,it is verified that the PID flow control algorithm is feasible.The variable spray system achieves the function of automatic adjustment of the spray flow rate with the flight speed,improves the overall uniformity of spraying,and can meet the basic requirements for small-area operations.