Feature Extraction Of Storage Grain Nephogram And Application Of Supervision Method

As an intermediate process between the two links of grain production and circulation,grain reserves are an important basis for adjusting the relationship between grain supply and stabilizing the grain market.Therefore,ensuring the security of grain reserves is one of the keys to maintaining national food security.At present,the supervision and inspection techniques adopted by China to ensure the security of grain reserves are mostly manual investigations,this method requires a lot of time and personnel to participate,and it is difficult for supervisors to obtain historical and warehousing information of grain depots in a timely and accurate manner.Therefore,in order to reduce the dependence of supervision and auditing technology on human resources and improve its technical level,it has great significance to study the modern basic state detection and supervision technology of grain storage.Based on the evolution law of historical grain temperature data of granary,this paper explores the characteristic quantity that can reflect the basic state of grain storage,and on this basis,designs the grain storage supervision system,achieves the analysis and judgment of the basic state of grain storage,finally,the reliability of the system is verified by the actual grain temperature data.The main research contents of this paper are as follows:(1)From the two perspectives of quality and quantity,the basic state of grain storage grain is divided into: empty granary status,half granary status,new grain status,outbound status,condensation status,and fever status.(2)According to the spatial distribution law of grain temperature,from the variation of each layer,the coefficient of the fitting function of grain temperature,the isotherm curvature of grain temperature nephogram,three angles to analyze the evolution law of it and propose a condensation prediction model based on grain desorption CAE equation.Through the analysis of historical grain temperature data,it is found that variance and coefficient variation of the grain temperature fitting function can effectively distinguish the basic state of the granary;the curvature of the grain temperature nephogram isotherm can reflect the change of the temperature field in the grain bulk in a certain extent.The condensation time and condensation area predicted by the condensation prediction model are in line with the actual experience of granary storage.(3)From the grain temperature prediction model,the correlation coefficient and autocorrelation coefficient between the difference section of the grain bulk,and the ratio of the circumference of the multi-isothermal line,three aspects to analyze the the changes of the grain temperature data over time.It is found that the grain temperature prediction model added the linear term can reflect the linear growth trend of grain temperature caused by long term grain storage;the autocorrelation coefficient of the difference inner layer and section of the grain bulk and the ratio of the length of the isotherm can effectively distinguish the basic grain storage status.(4)Based on the evolution law of historical grain temperature,the storage grain supervision system was designed and implemented by Lab VIEW.The system has six basic modules includes database connection module,data cleaning module,data analysis module,nephogram display module,file saving module.The implementation methods and principles of each module are briefly described.Finally,the reliability of the system is verified by the historical grain temperature data of the real granary.