Research And Development Of Precision Fertilizer Proportioning Control System

Irrigate water shortage in China and serious pollution of chemical fertilize.In order to maintain the sustainable development of agriculture,the research on the control and management technology of irrigation fertilization has been paid more and more attention.With the rapid development of science and technology,more new technologies have been widely used in agricultural irrigation and fertilization.At home and abroad,the control and management techniques of agricultural irrigation fertilization have been studied.However,compared with foreign excellent technology,the domestic research started late and the technology is relatively backward,and there is a large gap.Although foreign equipment is relatively mature,due to differences in crop growth factors,climatic environment and soil conditions,it is difficult to meet the actual needs of China.Moreover,there are few studies on the precise proportion of water and fertilizer in China,and most of the equipment has low accuracy and the system is expensive.Therefore,it is necessary to design a set of reasonable and inexpensive water fertilizer precision matching control system to meet the social needs.This study through the system structure,matching method,the control algorithm,software and hardware design,such as research,design a set of precise proportioning control system,water through nutrient solution proportion deployment and the concentration of a solution of water ratio of precision,makes a basis of solution for the crop growth,to improve the quality,yield,and to save energy and protect the environment.The main work and results are as follows.(1)System demand analysis and overall design.In view of the user requirement analysis,made clear the system applied to a single glass greenhouse soilless cultivation crop production,need to set four necessary for crop nutrient solution for proportional allocation,and to set the concentration ratio of precision irrigation water,mother liquor and concentration error must not exceed 5%,system still need to have regular quantitative irrigation and wireless remote control,and other functions.According to the demand analysis,this paper designed the human-computer interaction module,the mother liquid mixing device and the ratio of irrigation water three function modules,respectively set up fat absorption pump,vacuum pump solution flow mathematical model of water flow sensor and solution of water flow,the mathematical model established the nutrient solution mixing method and the ratio of sewage sludge concentration ratios.(2)Fuzzy PID control algorithm research.Based on the establishment of the sewage sludge concentration ratio method,this paper designs the precision ratio of water control system of fuzzy PID controller,will has a good robustness and high reliability PID algorithm combined with the traditional intelligent control method,based on the theory of input and output fuzzy variables and their domains of design,defines the membership function of fuzzy subset,design the fuzzy controller control rules,established the fuzzy method,the fuzzy PID controller output direct effect to the fat absorption pump control modules,realization parameters online adjustment,ensure the accuracy and stability of the preparation.(3)System hardware design.According to system function demand analysis,to determine the various pipe diameter selection and succession,determine the fat absorption pump,vacuum pump,flow sensor,and solenoid valves,and other important components selection,selected HMI panel as the human-computer interaction module,control in the mother liquor in the deployment of equipment and the ratio of irrigation water data acquisition and control unit selects STM32F103 microcontroller,between the equipment modules through three CC2530 module for wireless communication.The circuit of power supply module,wireless communication module circuit,serial communication module circuit and actuator drive circuit are designed.(4)System software design.A software design according to the system function module,CC2530 modules completed the ZigBee wireless communication software design,human-computer interaction module completed the HMI screen control in the software design and realize the function of serial communication,serial interface driver software design,mother liquor mixing equipment module and the ratio of irrigation water in the module completed the STM32 MCU software design.(5)System performance test analysis.By experimental test shows that the precision ratio of water stable control system module are able to work effectively,the mother liquor blending equipment can according to pre-established nutrient solution mixing proportion of precise allocation,the deployment of error less than 5% of all stripes,irrigation equipment can be set according to the concentration ratio of sewage sludge to mother liquor and the ratio of water to the stability of the irrigation water,and the concentration ratio of error is not more than 5%,meet the requirements of actual control.Friendly human-computer interaction interface module system easy to operate,can real-time display the various parameters of the water solution and working condition of each device module can satisfy the precision ratio of water in the actual production needs.To sum up,the nutrient solution ratio and the precise matching method of water and fertilizer,as well as the research and development process of the fuzzy PID controller and the precise matching control system of water fertilizer,have provided a new thinking and positive reference value for the research on the integrated irrigation technology of water and fertilizer.