Test And Research Of Microwave Yield Monitoring Sensor Based On CAN Bus

Yield monitoring sensors play an important role in agricultural production.Accurate yield measurement can draw attention to low-yield areas and verify the application effects of planting management techniques.The traditional method of measuring production is to weigh with a platform scale,which is not accurate enough and the error is relatively large.At present,there are three commonly used output monitoring sensors: impulse type,radiation type and volume type.In the process of output monitoring,the impulse type and volume type have large errors and cannot meet the requirements of precision agriculture.The radiation type is harmful to the human body,difficult to operate,and is subject to more constraints and is rarely used.Compared with the previous ones,A method of production measurement.The microwave yield monitoring sensor adopts a non-contact method of production measurement.It relies on the microwave module installed on the combine to emit microwaves to the grain outlet,which is reflected by the crop and then received by the sensor to obtain the frequency difference,and then perform data processing and analysis.,And then get the yield of the crop.Aiming at the current problems of low field production measurement methods,high price,complex structure,and relatively large errors,this paper consults the current research status of production measurement accuracy of production monitoring sensors at home and abroad,and proposes a microwave production monitoring sensor based on CAN bus.The frequency difference between the transmitted wave and the echo is used to measure its production measurement accuracy.The specific research work in this paper is as follows:1.Through the frequency information covered in the echo signal of the microwave output monitoring sensor,the calculation relationship between speed and frequency is obtained,and the speed is tested by the sensor,and different microwave signal spectrum analysis algorithms are compared and analyzed to determine and Use the Zoom-FFT analysis algorithm to calculate the zoom-FFT refined frequency spectrum to obtain the speed,study the factors that affect the movement speed during the monitoring process,and verify the measurement accuracy of the sensor.2.Monitor the output through the bench test,use the data acquisition instrument to collect the echo signal of the microwave Doppler,analyze the waveform characteristics of the signal,and determine the appropriate installation location through the algorithm analysis and comparison.Establish the linear relationship between the power spectrum density and the falling flow rate of soybeans,perform linear fitting to obtain the relationship between the falling flow rate of soybeans and the power spectrum density,control the falling flow rate of soybeans on the test bench,and obtain the power spectrum density by calculating the echo signal.The power spectrum density of is substituted into the relationship between the soybean falling flow rate and the power spectrum density to obtain the measured value of the soybean falling flow rate.Comparing the measured value with the actual value,the average error rate is 5.915%.3.Conduct field harvest experiments at Zhaoguang Farm,install the microwave yield monitoring sensor production measurement system on the combine harvester,record the yield data,process the yield data and GNSS data through Matlab software,and plot the yield with longitude and latitude Trend chart,by observing the yield trend chart,you can directly see the yield distribution of soybeans and corn.