Research And Development Of Intelligent Control Expert System Of Storing Grain Mechanical Ventilation

China is a huge agricultural country, and the national economic system is based on Grain. Although the total grain output is up to 5 hundred million tons every year, only 80 percent of them is used rationally. The main reason for loses in the course of storing the grain is that most of grain wares out and becomes bad. Researching for many years, domestic and international experts have come to the conclusion that the most suitable method of reducing loses is ventilating the barn on time to guarante the storing condition. But so far there has not been a socialized, intelligent, automatic and modern safe security system of storing grain.This thesis has constructed sophisticated automatic control system for grain barn ventilation according to "technical regulation of storing grain mechanical ventilation". Furthermore, we have established expert system of storing grain mechanical ventilation.The main contents are described in the following.1. According to the on-the-spot condition, we have finished the design of control system hardware which can control the three centrifugal fans at the bottom of the barn, the four exile fans on the top of that, three automatic ventilative doors on the edge of respective centrifugal fan, four automatic ventilative windows on the edge of respective exile fan, the other four which is distributed on the both side of the barn, so that six ventilative aims and nine ventilative ways claimed by Techinal Regulation of Storing Grain Ventilation can be realized.2. The software of control system has been exploited to aim at diversity of ventilative aims. The software realizes the following three functions: the realization of PLC wireless communication, ventilative controller and hareware diagnosis.3. Temperature of each cable point in the grain barn is obtained from the database of grain status. Inserting function referring to three-dimensional serendipity eight-node linear cell is built to show the grain temperature distribution in the form of three-dimentional colorful nephogram just like the result of the finite element analysis, which perfectly combines computer graphics with grain status inspection system. By three-dimentional colorful nephogram, the managers of the barns can master the varietyof the grain temperature, discover the fault on time, and take action against all kinds of fault as soon as possible.4. Expert system of storing mechanical ventilation has been built. The expert system consists of grain status fault diagnosis expert system and mechanical ventilative controlling expert system. Expert system is basically made up of fact base, kownledge base, reasoning mechanism, interpreting mechanism and human-machine interface. In the expert system the data of grain status from fact base are collected and made the statistics. The results of statistics will be taken out to match with regulations in the knowledge base. If the matching regulation is found, the only reasoning solution will be available for sure. Interpreting mechanism will provide the reasoning track and explanation of the very reasoning regulation. Human-machine interface mainly provide the interface between users and knowledge base plus inperpret mechanism.