Design And Analysis Of A Four-clip Type Pot Seedling Transplanting And Picking Device

At present,most of the domestic research on automatic transplanters are still at the semi-mechanical level,and manpower is still required to take seedlings and throw seedlings.The labor intensity is high and the transplanting efficiency is low,which greatly affects the promotion of seedling transplanting agricultural technology It is necessary to study the mechanization of transplanting machine to take seedlings and throw seedlings.The gripping device of the transplanter is an end effector that directly participates in gripping pot seedlings during the operation,and its structure and size affect the efficiency of trapping seedlings and the damage to pot seedlings when taking seedlings.Therefore,it is particularly important to design a gripping device with high gripping efficiency,low damage to pot seedlings,and stable working performance,for improving the automation of transplanting operations,reducing the labor intensity of transplanting operations,and improving the success rate of transplanting.This subject is mainly studied from the following aspects:(1)In order to design the gripping device more in line with the actual requirements of crop transplanting in Xinjiang,this paper studies the influencing factors of the compression resistance of processed tomatoes in Xinjiang.Analysis by multi-group orthogonal test: the following factors have an effect on the stress resistance of pot seedling substrate and the optimal combination of factors,The ratio of the plug seedling substrate(peat: vermiculite:perlite),the moisture content of the substrate and the clamping angle of the transplanter clamping device and the pot seedling substrate and the amount of change in the clamping angle.It provides a theoretical basis for the cultivation of plug seedlings and provides a reference for the subsequent design research of the gripping device.(2)By analyzing the size of the tomato seedling substrate,we can know the maximum clamping angle when clamping the finger into the hole.According to the effect of different compression speeds on the substrate gripping and the mechanical properties of the matrix under 2mm/s compression speed,the mechanical properties were tested.Through a comparative experiment,the relationship between the pressure resistance and the amount of deformation of the pot seedling substrate is affected by the compression speed during gripping,the compression speed suitable for picking pot seedlings is analyzed and selected.And through the analysis of the starting point,yield point,and breaking point of the mechanical properties of the pot seedling substrate at a compression speed of 2mm/s,the appropriate gripping force of the pot seedlings was studied.(3)Through the analysis of the needs of the transplanting device gripping device,combined with the agronomic requirements of the plug seedling seedling,the pot seedling transplanting device gripping device is designed.Determine its characteristic parameters and requirements,materials,driving methods,and design the overall system of the clamping device,so that the four-clamp-type pot seedling transplanting and clamping device,the operation principle and function meet the requirements.(4)In order to improve the success rate of transplanting pot seedlings and reduce the damage to the substrate by the clamping device,the center distance of the clips was used asthe optimization index and the clamping angle was used as the evaluation index.An optimization model of the end-effector actuator was established,and the mechanical parameters were completed using Matlab software,optimization.Through the design of the key components of the clamping device,it can be known that the thickness of the clip is 1mm,the upper side of the trapezoidal clip at the end of the clamping finger is 12 mm long,the bottom is 6mm,and the clamping depth is 26~29mm;the length of the frame is 79.2mm And the frame is symmetrical structure;the diameter of the driving rod is 5mm;the H,"+"-shaped connector to adapt to the movement mode;and the four-wire two-phase 57HB113-401 A stepper motor is selected as the power source.(5)Using solid works,a three-dimensional model of each part of the four-clip type pot seedling transplanting and clamping device is established,and the virtual prototype of the clamping device is assembled and interference inspection is performed.The motion analysis of the gripping device’s movement path through ADAMS shows that the gripping device’s movement is smooth and without impact.Then,the kinematics analysis and dynamic simulation verification of the gripping device are performed,and the simulation analysis shows that: During the process of clamping the seedlings,the displacement of the driving rod of the seedlings from the fully opened state is 2.90~3.18 mm,the displacement of the driving rod after clamping the finger to contact the seedling substrate is between 0.32 and 0.60 mm,and the moving speed of the driving rod may be 3 to 5 mm/s,and the relationship curve between the clamping angle and the contact force in the closed motion state verified that the change in the clamping angle is(2~3)°,which is a reasonable value for the change in the clamping angle.Suitable for picking and picking force.Further,the finite element analysis software ANSYS was used to analyze the stress and strain of the gripping device,which verified the feasibility of the design strength.