Research On The Control Model And Control System Of Moisture Content Of Grain Discharged From Mixed Flow Drying Towe

In response to the issue of high moisture content after corn harvest,which is not conducive to safe storage,in order to achieve the national safe storage goal of keeping the moisture content of corn after drying at 13%～14%,a research on the control model and control system for the moisture content of mixed flow drying tower grain has been carried out.By analyzing the basic theory of drying towers and drying mathematical models,a BP neural network model and a PSO-BP neural network model were established.Based on the drying mathematical model and control algorithm,combined with neural network,a mixed flow drying tower control system was designed.The data was uploaded to the corn moisture content monitoring system through hardware data acquisition and wireless transmission modules,and precise control of the drying process was achieved through control software and control algorithms.The main research content is as follows:(1)Elaborated on the principle of corn drying,analyzed the form of moisture content,drying process of each drying stage,and drying mathematical model,and simulated and analyzed the factors affecting the moisture content of corn through Matlab.(2)In order to control the moisture content of corn out of the machine,the moisture content of corn in the machine,the temperature of corn in the machine,the temperature of hot air in the three drying sections,and the wind speed of hot air in the three drying sections are taken as the input,and the rotation speed of grain discharging motor is taken as the prediction output.A BP neural network model is built.Combined with particle swarm optimization,a PSO-BP neural network model is built.(3)Based on the PSO-BP neural network prediction model and combined with the Page drying mathematical model,a drying tower model predictive control(Model Predictive Control,MPC)was designed.By transmitting the MPC optimal control signal to the grain discharge speed motor frequency converter to control the motor frequency,and combining with the PID control algorithm to accurately control the drying hot air temperature of the three drying stages,a control model for the moisture content of the corn output from the drying tower is constructed.(4)Design the software and hardware of the mixed flow grain drying tower control system,collect the hot air temperature and corn moisture content during the drying process of the drying tower through hardware modules,and upload the data to the corn moisture content monitoring system through communication modules.By controlling and adjusting the hot air temperature and grain discharge motor through control models and algorithms,precise control of the moisture content of corn drying machine is achieved.