Design And Research Of Spray System For Plant Protection

With the development of the modern agricultural mechanization and the demand for precision agriculture, the requirement of pesticide application technology is also increasing;however, there is a considerable disadvantage in the traditional spraying technology. So there is a tendency for pesticide application technology to develop a new type of plant protection spraying machinery which could meet the requirement of modern agriculture. Based on looking up many kinds of plant protection spraying machinery at home and abroad, it designs a spraying system for plant protection, with the integration of modern computer control and agricultural machinery. The system can adjust automatically or manually the volume of spray according to requirement, achieve the variable needs of spraying and make the spraying significantly improved.Firstly, It designed the overall structure of plant protection spraying system, analyzed the solution of this system, and built a model of spraying device, thus summarized that the main control parameters of spraying system are the motor speed, valve's flow and capacity of the fan, and built the main framework of spraying system.Secondly, In order to achieve variable spraying, the system adopted the method of pulse-duration modulation (PDM). In view of the system being mainly for the control of DC motor, this paper studied and analysized the D/C speed control system, and further discussed its stability, combining with modern PID control technology to achieve the purpose of precision spraying,which included increasing PID control algorithm and degree of expansion of the critical ratio of translation.Then, In order to achieve the automatic and manual adjustment of control volume, change the spraying amount, and reduce the impact of natural environment, adjusted the controlled source by making use of the MCU technology. So it can change the spraying mode according to different crops information, and achive spraying on-demand. It described the MCU system and peripheral circuits, which included power system, D/A transfer module, keystroke module, and communication module between the master and slave machine etc, and designed related software.Finally, It conducted an indoor and outdoor experiment for the plant protection spraying device, and made a comparsion with conventional sprayer. Tests have shown that the designed spraying system has greatly improved in the spraying's effect and homogeneity which not less than percent of 4.2. Meanwhile,the droplet diameter which changed between 13μm～90μm and flow which changed between 440mL/min～660mL/min could be controlled. Furthmore, the system is stable and reliable, which met the design requirement.The system can change droplet and spraying amount according to different spraying targets, thus saved up pesticide effectively, and reduced the pollution on agricultural ecological environment. The research of this project provided a practice basis for intelligent spraying and precision agriculture...