The Design And Research Of Intelligent Grain Situation Monitoring System In Grain Depot

Grain is an important national strategic commodity, is also the fundamental reliance of human survival, the security of grain storage is very important. In order to decrease the loss of grain in storage because of grain interior heating and mildew, it is necessary to examine various physical variables of grain in storage in real-time, and then estimates the situation of stored grain based on the data measured so that can eliminate the hidden dangers as soon as possible. At present, domestic grain situation monitoring system has the disadvantages of single function, low universality and poor extensibility, which is difficult to provide detailed and accurately comprehensive analytical report and scientific decision-making support. This system had shortages of complex route, low cost performance, difficult maintenance, less secure, therefore, it is phasing out.Combining with the one wire technology and fuzzy reasoning technology in view of the existing problems in the grain situation monitoring system, the author designed a intelligent grain situation monitoring system in grain depot, which is consist of communication host, monitoring and control extension, acquisition terminal, ventilation control, data analysis of grain condition. Specific features are as follows:(1) The system supports wireless data aggregation and transmission, which in the wireless transmission mode is flexible to organize network and easy to wiring. The designed measurement and control extension has the relay forwarding function, and can make the system realize the long-distance data communication of several kilometers.(2) The system supports two working mode. One is real-time detection mode: the communication host gives introductions to the measurement and control extension. The measurement and control extension executes the introductions, starts the data acquisition operation of sensor. After that, the measurement and control extension sends the collected data to the host, then the host uploads the data to the upper computer; the other is inspection mode:the host starts automatic timing check and sends the collection command at regular intervals to the extension, after the extension sending the sensor data to the host, the host stores the data in SD card, then the upper computer will extract the history data. If it cannot extract the data timely, the data will be updated continually in SD card.(3) The system supports the function of multi-data acquisition and ventilation. The measurement and control extension takes the microcontroller ATmega128 as the core components, which can be mounted many kinds of sensors, such as temperature sensor, humidity sensor, moisture sensor and material level sensor. If the upper computer judges the situation of temperature or humidity abnormal, by the host, the instruction to "open the window for ventilation" is sent to the ventilation control panel. The ventilation panel can open field equipment and open the ventilation windows by setting the relay.(4) For the problem, that is only relying on the single grain data, the situation of grain storage cannot be measured comprehensively. The evaluation model of grain quality, which is designed based on BP neural network, can make a fuzzy treatment to the data of temperature, humidity and moisture, and provide a more complete and accurate the evaluation of grain situation.The grain monitoring system designed in this thesis has been widely used in many domestic granaries, can the real-time monitoring and effective evaluation to the grain security situation inside the grain depot, overall functions have got the user’s recognition.