Research And Development Of Water And Fertilizer Integration System Based On Internet Of Things

From 2004 to 2017,the Central Committee of the Communist Party of China issued the Central Document No.1 successively,emphasizing the importance of efficient agriculture in the development of socialist modernization,and strengthening reform and innovation to build agricultural modernization.The integrated system of water and fertilizer can realize precise fertilization of various types of crops in large and medium-sized agricultural parks,save labor and time,improve fertilizer utilization rate and improve environmental pollution caused by agriculture.At present,the fertilization control strategy of domestic integrated system of water and fertilizer is mainly based on conductivity EC and PH regulation.The fertilization mode is single,the price is expensive,and most of them need manual duty.Therefore,it is necessary to design an integrated system of water and fertilizer based on multiple fertilization strategies of Internet of Things to meet the social needs.This paper studies the system from the aspects of hardware and software system structure and intelligent algorithm,designs an integrated system of water and fertilizer based on the Internet of Things,and puts forward three fertilization modes:EC fertilization,flow fertilization and irrigation.The operation principle of water and fertilizer integration system was analyzed,and the overall structure of water and fertilizer integration was designed according to fertilization mode.A fuzzy-PID controller based on traditional PID control and fuzzy control is designed.The principle of the system is analyzed,and the system is built.The first-order linear lag mathematical model is established by preliminary test of the constant pressure water supply system to adjust the inlet pressure and flow rate.The simulation results show that the overshoot and the steady-state time of the fuzzy PID control are obviously improved compared with the traditional PID control,and the feasibility of the algorithm is verified.Based on the stability of PLC control,SMART S7-200 small-scale PLC produced by Siemens is selected.Fuzzy PID controller for EC regulation and PWM controller for flow regulation are designed based on PLC platform.The concentration of water and fertilizer is adjusted by using Venturi jet mixer,and the touch screen is used for operation and real-time monitoring.At the same time,it expands the transmission equipment of 4G wireless network,realizes remote monitoring by using micro-message program,and guarantees the safe operation of the system.Experiments show that the EC overshoot of water and fertilizer is less than 2%in EC fertilizer blending,and the system is stable within 60 S with high steady-state accuracy.When adjusting the flow rate,the error of fertilizer blending is less than 3%,which meets the requirements of system design.