Research And Application Of Fuzzy Control Method For Agricultural Greenhouse Based On PLC

In recent years,with the development of advanced control technology and intelligent control equipment,China's agricultural greenhouse industry is developing rapidly.However,the greenhouse crops tend to be diversified and can not be treated with a unified control model,and the model composed of a series of indicators,such as temperature,humidity and light intensity,is a complex nonlinear model,and it is difficult to establish an effective and clear model.Therefore,the environmental control level of greenhouse is always in the stage of manual control and simple automatic control,and the level of intelligence and electrification is low.This paper starts with two aspects: control platform and control technology.In order to ensure the stability and reliability of greenhouse control platform,programmable logic control is adopted.The controller PLC(Programmable Logic Controller S7-300)is used as the core,the fuzzy pid control technology is applied to improve the control effect of the greenhouse control system,and the configuration interface is made to debug and simulate the whole system operation logic,which verifies the feasibility of the design.The main contents of the study are as follows:(1)Based on the application background of Sui Yuan Glass greenhouse in Anhui Agricultural University,the control requirements,control structure and equipment selection of the greenhouse are studied,and the overall system scheme is designed,including the selection scheme and layout scheme of the multi-point sensor,Executive control scheme?(2)In view of the application background of agricultural greenhouse,the paper compares pid control with fuzzy pid control,proves that fuzzy pid control is better,designs fuzzy pid control strategy and establishes fuzzy control rules by using experience knowledge.The pid parameters are adjusted in real time by fuzzy reasoning,and the data collected by each sensor are fused to optimize the decision output signal to ensure the accuracy and real-time performance of the system?(3)The greenhouse control system is designed by using PLC control core.Firstly,the hardware configuration of PLC is carried out,then the PLC is programmedand debugged by using STEP7 software.Finally,the actuator and sensor are wired.The configuration interface is designed with Kingview software,and the logic and feasibility of the system are verified.