Design And Experiment Of Automatic Seedling Feeding Mechanism Of Vegetable Pot Transplanting Machine

As the country with the largest vegetable production in the world,vegetable industry has become the economic pillar industry in rural areas of China.At the same time,most of the vegetable planting in China is mainly manual,with low production efficiency.Mechanized transplanting can greatly improve the production efficiency of vegetables and reduce the labor cost.The seedling picking mechanism of the automatic vegetable transplanter developed by our group has been at the leading level in China after years of research,but the automatic seedling feeding mechanism used in conjunction with it is complicated in structure and easily causes the phenomenon of jamming,which makes the transplanting efficiency low.Therefore,in view of the above problems,a simple and reliable seedling feeding mechanism is designed,which can cooperate with the seedling picking mechanism and seedling planting mechanism of the automatic vegetable transplanter,thus realizing the full automation of vegetable transplanting and improving the transplanting efficiency:（1）Based on the size of the selected cavity seedling tray and the motion mechanism of the matching seedling picking mechanism,the design requirements of the seedling feeding mechanism are proposed,and the design scheme of the transverse seedling feeding mechanism and the longitudinal seedling feeding mechanism are determined.A multi-link mechanism is adopted as the longitudinal seedling feeding mechanism,in which a four-rod mechanism is adopted as the longitudinal conveying mechanism and a combination of cam linkage and incomplete gear mechanism is adopted as the longitudinal driving mechanism;a double screw shaft assembly is selected as the transverse seedling feeding mechanism.（2）The mechanism parameters of the longitudinal conveying mechanism were firstly determined by using genetic algorithm to invert the mechanism parameters through the longitudinal seedling feeding trajectory;the longitudinal conveying mechanism auxiliary analysis software was developed based on Matlab software,and the inverse mechanism parameters were further optimized through human-computer interaction,and the design parameters of the longitudinal conveying mechanism were obtained:L₁=20 mm,L₂=40.7 mm,L₃=52 mm,L₄=66.67 mm,L₅=103.2 mm,β=113.8°,γ=11.1°.The design scheme and related dimensional parameters of the longitudinal drive mechanism,the one-way control assembly and the platen assembly were determined,and the related design parameters of the double helix shaft were determined.（3）The 3D model was established,and the virtual assembly of the seedling feeding mechanism was carried out.Then the 3D model of the seedling feeding mechanism was imported into Adams for simulation and analysis,and the simulation and theoretical trajectories of the longitudinal seedling feeding mechanism were compared,and the speed and displacement curves of the longitudinal seedling feeding point and the accuracy of the transverse seedling feeding were analyzed to verify the rationality and reliability of the design of the seedling feeding mechanism.（4）The processing,assembly and commissioning of the automatic seedling feeding mechanism of the vegetable pot seedling transplanting machine and the prototype test were completed.The longitudinal seedling feeding mechanism was tested in idling to obtain the actual seedling feeding trajectory,and the longitudinal seedling feeding trajectory was compared with the theoretical and simulated trajectory to verify the reasonableness of the longitudinal seedling feeding mechanism design.The accuracy of the seedling feeding mechanism was verified by measuring the accuracy of transverse and longitudinal seedling feeding,and the obtained seedling.