Development And Experimental Investigation Of Real-time Detection System Of Droplets Deposition

In recent years,agricultural informationization and automation are the key direction of development in China while sensor technology and wireless communication technology develop rapidly.Based on capacitive sensor and wireless communication technology,a real-time acquisition system for droplet deposition was designed to obtain the droplet deposition after the spray operation.The working principle of the real-time acquisition system of droplet deposition was discussed and analyzed.The selection of main sensors,system node design and software design tasks were carried out.The influence of chemical liquid type,concentration and nozzle type on the relationship between droplet deposition and voltage was studied.That can provide a basis for the quality evaluation of spraying,which help to optimize the parameters of spray operation and improve the operation effect.This study on real-time acquisition system have an important influence for the development of intelligent agriculture.The main research work carried out includes:(1)The overall scheme of the droplet deposition acquisition system based on the capacitive sensor was designed to realize the real-time collection task of spraying.The droplet deposition acquisition system mainly includes information collection nodes and aggregation node.The data collection node includes temperature and humidity information collection,droplet deposition collection and GPS information collection,which can obtain temperature,humidity,deposition,and positional information data.The aggregation node includes a storage module and a display module,which can implements parsing and storing data sent by the collection node.(2)Complete the main sensor selection of the system: DS18B20 temperature sensor,DHT11 humidity sensor,ATK-NEO-M8 N GPS module and capacitive sensor;STM32F407 is selected as the core data processing chip of the aggregation node,which realize data receiving and sending,and parsing the working state data of each module.Droplet deposition collection node was designed based on the CC2530 to realize data collection and transmission.Combining hardware selection and software writing completed the design of the droplet deposition collection system;Complete the design of drop deposition node task and temperature and humidity node task;Complete the design of the communication task between the sensor node and the aggregation node is completed based on the ZigBee;Complete the design of GPS information collection tasks,data storage tasks,and abnormal alarm tasks for each module.(3)Carry out laboratory tests using the above designed droplet deposition acquisition system,and then design the deposition measurement algorithm based on the results of experiments.Experiments were carried out using different nozzles(ST110-01,ST110-015,ST110-02 and ST110-03),different solutions(water,emulsifiable concentrates(EC),suspension concentrates(SC)and aqueous solutions(AS)).The deposition-voltage model was established according to experimental data regression analysis for completing the algorithm design.The result show that the regression equations of the voltage output by the capacitive sensor and the droplet deposition were established for the four solutions of water,EC,SC and AS,the correlation coefficient of the four regression equations was around 0.95.It provided the basis for later algorithm design and system application.(4)The hardware working conditions of the droplet deposition collection system and the experimental error test was carry out.The test result proved that the system can complete the realtime data collection and data transmission.According to comparing the data using the weighing method with the data collected by the droplet deposition acquisition system,the result was got: when selecting the glyphosate(AS)as the spray solution,the error is the smallest,at about 8%;when selecting atrazine(SC)as the solution,the relative error is slightly larger.The main reason is that the error of the deposition detection algorithm(when the solvent is difficult to dissolve in water,select the deposition detection algorithm of water for measurement)and the measurement error work together,and the error reaches about 12%.The final analysis results show that the average error of the deposition detection algorithm is about 10%.So deposition detection algorithm can stably and accurately reflect the quality of spray and meet the needs of actual agricultural work...