Design And Test Of Automatic Picking And Throwing Device Of Pepper Transplanter

China is the world’s largest producer,consumer and exporter of pepper.However,as the low level of transplanting mechanization,pepper transplanting method like manual operation or semi-automatic is still used as a common way which couldn’t avoid the deficiencies such as high labor intensity,high injury rate and low efficiency.The domestic market provided automatic transplanting machines with few types,high prices and complex structures,and the theoretical research on seedling picking and throwing technology are usually insufficient.Defects such as low success rate,high seedling injury rate,and poor stability seriously affected the quality of transplanting.Aiming at solving the problem of high seedling injury rate and poor stability of traditional pepper transplanting machine,an automatic device for seeding picking and throwing based on the joint structure of the clip and puncture was proposed in the research.At the same time,a pneumatic drive system was designed based on the operation type of whole row seeding picking and interval seeding throwing.Mechanical properties of pepper plug seedlings with good growth and suitable transplanting condition were tested,according to which the theoretical analysis and structural design of the device were carried out.The operating form of the mechanism was determined and the key operating parameters were optimized with the help of computer simulation analysis and test verification.Finally,sufficient theoretical evidence was provided for the mechanized transplanting of peppers.The main contents and results are as follows:(1)Research on physical and mechanical properties of pepper plug seedling.The physical and mechanical properties of the substrate and stem of pepper seedling were studied and analyzed,which could not only provide theoretical basis but also offer reference for the key parameters setting of simulation analysis.(2)Design of seedling automatic picking and throwing device and pneumatic system.An automatic device for seeding picking and throwing based on the joint structure of the clip and puncture was proposed,and the structure and working principle of it was analyzed.The kinematics and dynamics models of end-effector were established.A 3D model established by Solid Works was used to test the interference of the device and analyze the movement trajectory of the end-effector with ADAMS.(3)Simulation and analysis of the automatic picking and throwing device.Fluid SIM-P3.6 was used to simulate the response time sequence of pneumatic actuator.The DEM-MFBD co-simulation was carried out to analyze the process of transplanting.The mechanism of plug seedling damage and the effect of key factors on the success rate were revealed,which provides a basis for further optimization of key parameters of end-effector in seedling picking process;By finite element simulation,the structure of the finger was optimized and the best material of cushion gasket was determined.(4)Optimization of end-effector key parameters Based on the theoretical analysis and simulation optimization results,the test bed of automatic seeding device was built.Aiming at the success rate of seedlings picking and the loss rate of substrate,the single factor test and analysis were carried out on the key factors such as needle interval,needle insertion stroke and needle insertion angle.Combined with the results of single factor test,the orthogonal test,variance analysis and response surface analysis were carried out,which concluded that the influences of each factor on the success rate of seedling picking were,in descending order,the needle interval,the needle insertion stroke and the needle insertion angle.The influences on the pot loss rate were,in descending order,the needle insertion angle,the needle interval and the needle insertion stroke.Through response surface analysis and multi-objective optimization,the optimal parameters were obtained as follows: needle interval as 12.25 mm,needle insertion angle as 50.37°,needle insertion stroke as 14.21 mm.(5)Verification and analysis of field test.Field test based on the rounded best parameters illustrated that the seedling success rate and substrate loss rate were respectively 97.86% and2.19%,which well satisfied the requirements for pepper plug transplanting.