Design Of Intermittent Spraying Control System For Maize Self- Propelled Sprayer At Seedling Stage

For a long time,the effective method to prevent pests and diseases in agriculture is to spray pesticides on crops.However,compared with other developed countries,the backwardness of pesticide application technology in our country leads to a large amount of waste of pesticides.The lower utilization rate of pesticides not only raises the cost of controlling diseases and insect pests,but also destroys the ecological environment.Especially for the field planting of maize crops in Xinjiang,the application area is large and the amount of medicine used is large.In order to improve the utilization rate of pesticide in our area,the application of variable pesticide application technology was put forward.Taking maize plants in seedling stage as the research object,a set of intermittent pesticide application control system suitable for self-propelled spraying machine was designed in order to improve the pesticide application effect and reduce pesticide pollution.The main research contents of this paper are as follows:(1)From the perspective of applicator and applicator technology,the research status of intermittent applicator control system at home and abroad was reviewed.By comparing the literature results of detection sensor of the object and combining with the characteristics of the object of this study,the ultrasonic sensor was selected to perceive maize plants in seedling stage.According to the design purpose and requirement of the system,the technical route is determined.(2)Set up the intermittent application control hardware system: designed the intermittent application hydraulic circuit,and determined the hydraulic component parameters;The electric control system based on PLC is developed,the external circuit of PLC and the drive circuit of solenoid valve are planned.(3)The system pressure control model and flow control model were constructed,and the variable control model of intermittent spraying was established based on the ultrasonic detection height of crops.The pressure stabilization control algorithm based on PID was studied and the model simulation analysis was completed.(4)Designed the system control software based on PLC,and completed the upper computer software development.(5)The test bed of intermittent pesticide application control system was built.The test results of intermittent pesticide application platform in seedling stage showed that the performance of intermittent pesticide application control system was good,the accuracy error of flow control was within ±5.57%,and the relative error of pressure closed-loop control was within ±4.71%,which met the operation requirements.