Design And Test Of Granular Fertilizer Metering Device For Rape Direct Seeder

For purpose of solving the problem of granular fertilizer real-time detection in fertilization operation of rape direct seeding machine,the research on granular fertilizer discharge and application counting device of rape direct seeding machine was carried out.Based on the idea of shunt multi-channel parallel detection,a set of granular fertilizer discharge and application counting device of rape direct seeding machine was designed by using photoelectric detection method,and bench test and field test were carried out,which provides a feasible method for realizing real-time detection of granular fertilizer discharge and application.The main research contents and conclusions are as follows:(1)The overall scheme design of granular fertilizer discharge and application counting device of rape direct seeding machine was carried out.In order to solve the problem of high-throughput granular fertilizer real-time detection,based on the analysis of the research status of granular fertilizer sensing and detection system at home and abroad,combined with the needs of granular fertilizer real-time detection,the idea of shunt multi-channel parallel detection was proposed.The infrared detection method and led silicon photodiode detection method were compared and analyzed,and the real-time detection scheme of granular fertilizer discharge and application based on thin surface light and no blind area parallel sensing was optimized.Therefore,the installation position relationship and key parameters of the sensor module were determined.On this basis,the number of shunt channels was calculated to be 8 through theoretical analysis,that is,the shunt detection form of "one to eight" wasadopted.(2)Design of key structural parameters of sensing device.The application frequency of granular fertilizer in rape direct seeding machine can reach 500 Hz,which makes it difficult to detect granular fertilizer in real time.Aiming at the problems of large flow and disorder of granular fertilizer,the key parameters of uniform fertilizer structure and diversion structure were designed.Edem simulation and bench test were carried out to verify the shunting uniformity and anti blocking performance of uniform fertilizer structure and shunting structure.Edem simulation results is 0 ° ～ 5 °,the consistency variation coefficient of granular fertilizer discharge in each channel is not more than 5.78%,and there is no blockage.The bench test results show that when the inclination angle is 0 ° ～ 5 °,the use of uniform fertilizer structure reduces the coefficient of variation of pipeline displacement consistency from 15.94% to 8.46%.The uniform fertilizer structure has an obvious effect on improving the shunt uniformity of the sensing device without blockage.(3)Design of for sensing device.A multi-channel signal acquisition and processing system composed of signal sensing module,signal conditioning circuit,power supply module,main controller and OLED display module is designed.The signal sensing module is composed of LED lamp and silicon photodiode to obtain the original signal of particle fertilizer falling.A signal conditioning circuit composed of filter circuit,two-stage amplification circuit,half wave rectification circuit,voltage comparison circuit and photoelectric coupling circuit is designed.Eight original signals are conditioned into square wave pulse signals and input into is used as the main controller,and the external interrupt function of the single chip microcomputer is used to count the pulse signal of granular fertilizer.The detection information is displayed in real time by using OLED display screen.(4)Bench test and field test of sensing device.Through the bench test and field test of the sensing device,the reliability,accuracy and stability of the sensing device in the operation process are verified.The bench test shows that when the fertilizer discharge frequency is 500 Hz,the detection accuracy is not less than 85.6%;The field experiment shows that the detection accuracy is not less than 84.1% at the fertilizer discharge frequency of 500 Hz.In the bench test and field test,the sensing device works normally,runs stably,and there is no blockage in the device.