Development Of Data Processing System For Impact-based Grain Flow Sensor Based On DSP

That grain combine is working while obtaining flow information in real time is an important part of obtaining the information of crop yield distribution.Data processing system was developed based on TMS320F2812 chip.A core unit of the yield monitor system is the grain flow sensor.However,the vibration noise could affect the grain flow sensor obtaining the information enormously.An experimental platform was produced based on John Deere-3080A combine that grain flow sensor with double parallel beams was installed on.Research on the methods of data processing was carried out in view of the influence of vibration interference.The main results and conclusions were as follows:(1)The hardware of data processing system was designed with TMS320F2812 as the main chip,including signal conditioning circuit,minimum system circuit,external expansion memory circuit,and serial communication circuit.Signal conditioning circuit could realize the amplification and offset of weak signal.Minimum system circuit could realize data acquisition and processing.External expansion memory circuit could achieve the expansion of data and code storage capacity.Serial communication circuit could realize that lower machine can send the data processing results reflecting flow information to upper monitor.(2)The software of data processing system was designed with TMS320F2812 as the main chip,including DSP chip initialization program,ADC module sampling program,data processing program,and serial communication program.It could realize data acquisition and processing and display the result on the upper monitor finally.(3)Vibration interference elimination for the flow sensor with dual parallel beams was studied.The filter coefficients were obtained by the software MATLAB.The output signals of the two parallel beams were processed by low pass filter for 80Hz and then were processed by the method of adaptive interference cancellation.The experimental results showed that when the combine was vibrating with maximum amplitude in 0 angle position,data processing result was 0.0022V.And,the validity of the vibration interference cancellation method was verified.