Research On Temperature And Humidity Intelligent Control System Of Agricultural Products Baking

Baking is an important part of the agricultural production process. With theincreasing obviousness of the trend of China’s agricultural planting scale, specialization,modernization, curing barn baking is more and more common. This research will focus on the keytechnology of baking——temperature and humidity control in baking room. Difficulty of controllies in time-varying, hysteresis, coupling characteristics of temperature and humidity. On the basisof full understanding of agricultural baking process, this project designed intelligent controlalgorithm with the combination of fuzzy-PID and fuzzy decoupling. and this research achieves aprecise control of the temperature and humidity in the baking room by way of languageprogramming of LabVIEW (virtual instrument technology).Centering on research contents, the main work can be seen from the following:1. Research of curing barn. Based on the fact of tobacco demonstration bases in the areas ofSheqi county, Nanyang city, Henan province, this research aims at knowing the present situation,demanding situation of curing barn, and the significance of temperature and humidity control, andunderstanding main technical means of temperature and humidity control. And then, this projectmay find the improvement direction, and clarify the approach of system design.2. The general design plan of control system. this thesis analyzes temperature and humiditycharacteristics of controlled object curing barn. According to object properties, the general designplan of control system is chosen. After that, this research builds overall designs based on themodular, such as data collection, data processing, man-machine interaction, key informationdisplaying, etc.3. Research and design of intelligent control algorithm. On the basis of temperature andhumidity change characteristics in the process of baking, this project chooses to use the fuzzy PID.Based on PID control experiences, this research designs fuzzy control query table, and a fuzzymembership grade function is chosen and its algorithm fixed.This research adopt fuzzy decouplingmethod to reduce the coupling effect, and fixes fuzzy decoupling coefficient of the lookup tableand makes up for temperature and humidity control.4. The hardware design of control system. According to the need of the control system, thisproject designs on-site data collection and processing circuit, execution circuit,and other peripheral circuits,and gives the selection and configuration of equipment.5. Software implementation of control system. Based on the virtual instrument LABVIEW,this project performs concrete implementations, algorithm implementation, User interface (UI),etc. on control system of temperature and humidity, and compiles the fuzzy adaptive PID controland fuzzy decoupling rules of procedure.(1) Based on Matlab, concrete realization of adaptive fuzzy PID algorithm and fuzzydecoupling compensation. Temperature and humidity control meets the accuracy requirement ofthe baking process.(2) Based on LabVIEW, concrete realization of some functions, such as bake the objectselection, setting and displaying of temperature and humidity, temperature tracking curvedisplaying, current work status displaying, and so on.6. System simulation and experiment. It turns out that fuzzy adaptive PID control algorithmand fuzzy decoupling compensation method improve adaptive capacity and control precision oftraditional PID algorithm by simulated test and analysis of simulation result.