Grain Drying Control System Based On Total Weight Detection Research

Grain problem is the foundation of the national livelihood,the relationship between theglobal strategic cooperation, not only political problems but also economic problems, it’s theroot of it governance who lived in ages past. Grain drying automation is an important guaranteeof rich harvest of grain, also is the important embodiment of modern agricultural production.The research of this paper put the circulation of grain dryer as the object to research anddevelop the automatic control system, the automatic control system in addition to the simplecontrol part of the ordinary dryer, also real time test some influence drying processparameters,including the grain moisture detection, temperature detection, furnace temperaturedetection, hot air detection and exhaust gas temperature and humidity detection. The real-timedetection provide theoretical basis for the control theory, drying model real-time feedback thedegree of drying grain, effectively ensure the quality of drying grain, the whole system have thecharacteristics of automation, intelligent and accurate, it’s a leading of dryer control system atpresent. The main content of this paper is as follows:(1)This paper expounds the development present situation at home and abroad anddevelopment trend of grain drier, introduced the development process of grain drying controlsystem at home and abroad at the same time, introduced the dynamic to the development ofdrying machine control, and combining the current problems existing in the drying machinecontrol to put porward the research content and the practical significance of this paper.(2)Expounds the drying principle, the principle of total weight method of grain moisturedetection, principle of control system, etc., For continuous dryer drying process, conduct thetheoretical calculation of grain temperature, moisture and drying time and dynamic simulationof the process.(3)The hardware design of the control system, one of the part is with the single chipprocessor as the core of the hardware design for total weight detection of grain moisture，it canreal-time detect grain moisture and weight; the other part is the hardware connection among theman-machine interface and PLC and control cabinet, through real-time monitoring the touchscreen for drying in the process of grain moisture, the hot air temperature and the exhaust gastemperature and humidity, PLC realize the automatic control to the dryer.(4)The software design of the control system, including program design and thecommunication connection three parts. Touch screen interface with MCU communication to accomplish the data transmission and analysis of moisture detection; the touch screen and PLCestablishes communication to control the hot blast stove and the machine of discharge grain, thetouch screen and temperature and humidity sensor establishes communication to collecttemperature and humidity data.(5)The experimental calibration of weight testing grain moisture, through the calibration ofthe weighing sensor, build relations between the sensor and the weighing system, fitting therelationship between the frequency and the moisture, it can detect the grain weight and the grainreal-time moisture that in the dryer fast and accurately.(6)The research and development of automatic control system,will be developed by theautomatic control system of circulation of grain dryers as test object, the scene of the experimenton all hardware and software debugging operation, complete each sensor data collection, tocomplete a set with the drying machine form a complete set of automatic control system of graindrying real-time automatic control, so as to improve the efficiency of the grain drying, real-timedisplay of grain moisture and system operation condition, and to control the whole dryingprocess.