Design And Key Technology Research Of Hand-held Vegetable Tray Seedling Automatic Transplanting Machine

At present,China's vegetables production are first seeded in the tray and then transplanted.It is an urgent need for agricultural production and an inevitable trend of future development to develop a hand-planted vegetable tray seedling automatic transplanting machine which is suitable for operation in the facility to realize mechanized transplanting of vegetables,reduce labor intensity and improve transplanting efficiency and quality.The transplant of vegetables in China is mainly carried out by artificial and semi-automatic transplanting.The artificial transplanting efficiency is low,the labor intensity is large,and the transplanting effect is poor.The semi-automatic transplanter only replaces the artificial planting action and still requires a large amount of labor.In view of the domestic research,based on seedlings physical characteristics,a two-row hand-planted vegetable tray seedling automatic transplanting machine with small volume,small turning radius,light and easy operation was designed,and key technical research and performance test were carried out.The main contents and results of this paper are as follows:(1)Through the action requirements and process analysis of transplanting seedlings,the overall design scheme of the hand-planted vegetable tray seedling automatic transplanting machine was determined,and the structure and working process of the automatic transplanting machine were expounded.The design of the chassis structure is carried out to realize the design goal of adjustable adjustable planting distance of 400-600 mm and width of 900-1200 mm.The hydraulic system of the chassis was designed,and based on AMESim for hydraulic system simulation analysis,the design goal of lifting 150 mm in the chassis for 30 s is achieved.The transmission system was designed and calculated,the design goal of 40-60 plants/line/minute planting frequency and 200mm-500 mm planting distance is achieved.(2)The design of the picking seedling mechanism was carried out,the structure of the picking seedling mechanism is explained,and determine the working mode of picking the whole row of seedlings and casting seedlings at the same time.ADAMS and MATLAB/SIMULINK is used to carry out mechanical and pneumatic joint simulation of the picking seedling mechanism.The effect of laterally moving cylinder bore,spring diameter,wire diameter,effective number of turns and other parameters was analyzed on fast and accurate cast seedlings,and select appropriate mechanism parameters.(3)The design of picking seedling end effector was carried out,the structure and working mode of the picking seedling end effector were explained.The mathematical model of the picking seedling end effector was established.Combined with the mechanical characteristics of the seedlings and the distribution characteristics of the root,the structural parameters of the picking seedling end effector were optimized,and the virtual prototype model was established in RecurDyn.The mechanical properties of the carcass were measured by experiments,and the experimental data were processed to obtain the physical property parameters of the particles.The carcass particle model was established in EDEM.The EDEM-RecurDyn coupling simulation was used to extract the picking end effector for insertion,gripping and lifting.The influence of insertion depth and initial insertion depth on the picking seedling effect was analyzed,and a set of mechanism parameters and action sequence matching of the picking seedling end effector which can achieve better seeding effect were optimized.(4)The high-speed camera test of the seedling movement precision was carried out on the prototype.When the picking seedling end effector move to casting points,the maximum rebound amplitude of the middle picking seedling end effector is 2.7mm,which is 0.106 s from the impact rebound to the static stability,and verifies the correctness of the theoretical analysis.The shortest total time of picking seedlings was 2.416 s,and the theoretical maximum picking seedling rate was 74 plants/min,which met the design requirements.The picking seedling performance test was carried out.Under the three picking seedling speeds of 16 times/min,20 times/min and 24 times/min,the success rate of seedlings was greater than 95%.The whole machine performance test of the transplanter was carried out,when working at 40 plants/line/minute,50 plants/line/minute,and 60 plants/line/minute,the transplanting success rate was greater than 90%,and the variation coefficient of plant distance was less than 5%,and the upright rate of planting is more than 95%,which can meet the transplanting requirements.