Research And Design On The Grain Flowmeter

Mankind completely enters the information age in the 21st century. Technologies of sensors, communications and computer are the three mainstays of information industry. With the expansion of domain and space of human exploration, the variety of electronic information needed by human keeps increasing. It's urgently needed to increase the speed of transmitting information and strengthen the capability of processing information. As the antenna that is used to detect nature, sensor is the interface between the studied object and the information system, and also the window for the system to perceive, acquire and detect the information. Grain flowmeter play a very important role in the agricultural production process, but the related research is still relatively backward and the application is not popularized.Through working principle analysis of grain flowmeter, targeting at the disperse feature of grains and based on the Coriolis Force theory, one grain flowmeter measuring device was designed to convert the torque information of the rotating measuring axis to voltage signal and being capable of measuring and displaying the grain flux. The sensing mechanism scheme of the sensor was decided based on analysis and comparison, the parts were designed and the 3-D effect map was obtained.The sensing device for torque and vilocity measurement was studied in this paper, after comparison of several common torque sensors, the resistance responding torque sensor was selected and computation was carried; one digital velocity sensor was selected to obtain the velocity signal on the rotating measuring axis, combining with the sensor structure, the suitable motor and signal guidance device of flow-collection ring was selected.As for the hardware of the signal receiving system, the peripheral circuit with 89C51 micro controller as the core was designed, which include the corresponding signal amplifying module, A / D conversion module, the LED display module, as well as stabilized voltage supply, oscillation circuit, reset circuit and so on. Then the external circuit was designed using Protel; the software program was written using C Language and debugged under the uVision3 development platform,and simulation was carried using Proteus; Finally, the flowmeter was calibrated in static states and the error source was.By using the designed grain flowmeter, the high-precision and on-line measurement of grain flow was achieved. What's more, the measuring range can be adjusted by changing its velocity to suit different needs of measurement.