Design And Experimental Research Of Spoon Type Potato Precision Seed Metering Device With Three Claw And Reseeding System

Aiming at the problems of high missing rate and high multiple rate of potato seed metering device,this paper improved the fluidity of potato seed and the ability of seed spoon to take seeds as the goal,designed a spoon type potato precision seed metering device with three claw,and added the seeding detection and reseeding system.The combination of agricultural machinery and agronomy,comprehensively used theoretical analysis,structural design,intelligent control,discrete element simulation,bench and field experiments,etc.The purpose was to improve the seeding quality of potato seed metering device.Specific research contents and conclusions were as follows:（1）Determination of material properties of potato seed.Potato seed（Xindaping）were widely planted in northwest as research objects.Respectively used metric method,measuring bottle method,normal pressure constant temperature drying method,natural accumulation method,measured the three-axis size,mass,density,water content,natural angle of slope.Built slant instrument to measure static rubber coefficient and rolling stability angle.Provided theoretical basis for structure design and simulation analysis of precision seed metering device.（2）Structure design of spoon type potato precision seed metering device with three claw.Explained and analyzed their structural composition and working principle,completed structural design and theoretical analysis of key components,determined their main parameters.The taking seed principle and stability principle of the three-claw seed spoon and the common bowl-shaped seed spoon were compared and analyzed,Established mathematical model of the three-claw seed spoon about taking seed space and stress,the key factors affecting the seeding performance were determined to be the length of three-claw（w）,the three-claw bottom center distance（d）,the inclination angle of three-claw（θ）.（3）Discrete element simulation analysis of spoon type potato precision seed metering device with three claw.Created discrete element models of the seed metering device and potato seed,used the EDEM simulation software for single-factor test.Explored the effects of the three-claw bottom center distance（d）,the spoons distance（L₂）,and the separator heights（I）on the seeding performance.The quadratic orthogonal regression rotation combined test was carried out and test results were optimized:the length of three-claw（w）was 38.04 mm,the three-claw bottom center distance（d）was 16.00mm,the inclination angle of three-claw（θ）was 29.07°,and the driving wheel speed（n）was 53.05r/min.Through the speed changing simulation at different speeds,Contrast analysis of the effects of variable speed on the seeding performance,provided theoretical basis for the design of the reseeding system.The movement area and law of potato seed in the process of seed taking were analyzed,it was determined that the factors affecting the seeding performance.Through discrete element and finite element coupling,the three-claw seed spoon was accurately loaded,the strength and stiffness analysis of the three-claw seed spoon under optimal parameter conditions were completed,its strength and stiffness were determined to meet the requirements.（4）Design of seeding detection and reseeding system.Determined the structure,working principle and overall plan of the system.The hardware part mainly included power supply module,sensor module,single chip microcomputer module,execution module,liquid crystal display module and alarm module.The software part mainly included the main program,the display program,the data processing program,the reseeding program,the sound alarm program and the serial communication program.（5）Performance test of seed metering device and reseeding system.Through the bench test to verify the reliability of the simulation optimization results,and the accuracy test of detection module was carried out to ensure the accuracy of subsequent bench test.The performance comparison test of seed metering device with or without seeding detection and reseeding system was carried out,the results showed that the seed metering device installed with the system was compared with that without the system,The qualified rate was significantly increased and the missing rate was significantly reduced.The field test was carried out on the spoon type potato precision seed metering device with three claw,the results showed that it was within the operating speed range of 2～6km/h,the qualified rate was higher than 80%,the missing rate and multiple rate were less than12%,the variation coefficient of the seed spacing was less than 30%,which could meet the precision of potato technical requirements.