Research On Water And Fertilizer Precision Control System

At this stage,Chinese agricultural water and fertilizer irrigation methods should be flood irrigation,and the main application of fertilizers is coarse.The backward irrigation methods have caused serious damage to the ecological environment.Under the premise of continuous advancement and development of modern agricultural technology,combined with the actual situation of my country’s agricultural development,improving the utilization of agricultural water and fertilizer and the accuracy of fertilization have become research hotspots.Relying on greenhouse agriculture,this paper studies the precise coupling of water and fertilizer and the conditions of water and fertilizer irrigation in greenhouses,and designs a set of precise water and fertilizer control systems with the advantages of low cost,high precision,easy operation,and remote control in combination with related technologies of the Internet of Things.The specific research content includes the following four parts:(1)In order to study the factors affecting the coupling effect of water and fertilizer in the pipeline,this paper carries out a numerical simulation study on the effect of the three factors of fertilizer angle,fertilizer pipe diameter and water-fertilizer injection rate in the water-fertilizer coupling process based on the theory of computational fluid dynamics.The results and data analysis of the influence of different factors provide a theoretical basis for the subsequent design of system control schemes and fertilizer pipelines.The results show that the ratio of water and fertilizer injection rates has a greater impact on the coupling effect of water and fertilizer.At the same time,combined with the analysis of user needs,determine the overall design plan of the water and fertilizer precision control system,including the system control principle,control mode and control process,and make a feasibility analysis of the plan.(2)In order to realize the precise control of the ratio of water and fertilizer,based on the detailed analysis of the characteristics of agricultural water and fertilizer irrigation,this paper designs a PID water and fertilizer control model based on PSO and BP neural network optimization.System simulation is carried out through MATLAB.Compared with the traditional PID model,the improved PID model has better performance in regulating time and overshoot control.(3)According to the overall design plan of the system,design and implement the water and fertilizer precision control system.The system is composed of upper computer and lower computer.The host computer uses the Media Tek MT8753 development board as the main controller,which is equipped with the Android operating system and uses the Java language to develop system applications for outputting control instructions and realization of the water and fertilizer irrigation process(pipe wetting,simultaneous application of water and fertilizer,and pipe cleaning)data visualization.The lower computer uses the STM32 development board as the core,which is used to control the flow sensor to collect the speed of water and fertilizer in the pipeline and the speed of the water pump,and communicate with the upper computer through Wi Fi communication for data interaction.At the same time,this article also designs and develops data communication protocols and mobile apps to facilitate remote control by users.(4)In order to verify the actual performance of the water and fertilizer precision control system,this paper built the fertilizer pipeline and system circuit in the laboratory,and analyzed the system communication reliability,sensor data,PWM duty cycle and fertilizer absorption speed relationship,and system control effect The system function test was carried out.The test results show that the system can realize real-time regulation of the water and fertilizer irrigation process and precise control of the water and fertilizer ratio.Comprehensive analysis shows that the system conforms to the new agricultural concept of precise control and has certain engineering application value.