Design And Experiment Of Automatic Transplanting Machine Picking Device For Pepper Seedlings

Pepper seedlings are mainly planted by seedling transplanting,and it has been the trend to have automatic transplanting machines perform this process.The efficiency and quality of seedling transplanting are determined by the key mechanisms of the transplanter,such as the tray loading mechanism,tray feeding mechanism and seedling picking mechanism.Most of the domestic transplanters are still at the stage of semi-automatic manual tray loading,which has the problems of low operational consistency and high labor cost,while the stem clamping mechanism faces the problem of stalk damage to cavity seedlings.In order to solve the above problems,this paper designs a seedling picking device for automatic transplanting machine of pepper seedlings,which mainly contains key mechanisms and control systems such as upper tray mechanism,tray feeding mechanism and seedling picking mechanism.Based on the agronomic requirements of pepper seedling transplanting,the Japanese Ichinoseki 2ZY-2A transplanter chassis was selected,and the automatic transplanter for pepper seedlings was designed on the basis of the transplanter chassis,which mainly realized the functions of tray loading,tray feeding,seedling picking,seedling dropping,hole tray retrieval,linear driving,transplanting and soil mulching.The main research work and research results of this paper are as follows:(1)According to the selected tray size(530×280(5 rows×10 columns))and chassis,the overall scheme of the automatic seedling picking device was established,the 3D modeling of the tray loading mechanism,tray feeding mechanism and seedling picking mechanism was completed,and the working principle analysis and virtual assembly were carried out,and the automatic seedling picking device met the requirements of automatic transplanting of pepper seedlings.(2)Based on a review of the literature on the mechanical properties of pepper seedling stalk compression,it was concluded that the compressive strength in the range of 0.63-2.27 MPa and50% stalk compression ratio were the evaluation indicators for the elastic deformation stage of the stalk,providing a theoretical basis for the design of the two clamping mechanisms.The motion law of the motor screw type clamping mechanism is derived through motion simulation,and the clamping control strategy is formulated based on the motion relationship between the movement distance of the screw nut,the angle of rotation of the clamping piece and the movement distance of the end of the clamping piece.Through mechanical analysis,the spring stiffness coefficient of the electric actuator type clamping mechanism is 18.19N/mm,and the stress and deformation analysis of the clamping plate and the clamping plate fixed block is carried out by the finite element software ANSYS,and the maximum stress of the clamping plate is 60.49 Mpa,and the maximum overall deformation is 0.86 mm,and the maximum stress of the clamping plate fixed block is 1.624 Mpa,and the maximum overall deformation is small.The design strength was verified to be feasible.Compared with the test results of the motorized screw type clamping mechanism,the stalk compression ratio of the electric pusher type clamping mechanism is slightly lower than 15%,and the requirements for mechanism motion control and manufacturing cost are low,and the overall seedling picking effect is better.(3)Combined with the operational requirements of the device,the action logic of the seedling picking device and the flow analysis of the control system are studied,and a human-machine interactive control system of the seedling picking device based on FX3u-32 MT and Lab VIEW is developed and designed,which can realize the core functions of automatic tray loading,automatic tray feeding,automatic seedling picking and casting,speed regulation of the seedling picking mechanism and speed regulation of the tray feeding mechanism,etc.The seedling picking device can meet different transplanting requirements by adjusting the parameters.(4)Experiments were conducted to optimize the working parameters of the fetching device,and the test results showed that as the fetching efficiency increases,the fetching success rate and casting success rate of the fetching device decreases.When the seedling extraction efficiency was54 plants-min-1,the average seedling extraction success rate reached 97.36% and the seedling casting success rate reached 95.56%,which could better meet the requirements of pepper seedling transplanting.The research work in this paper provides a theoretical basis and reference for the design of a fully automatic transplanter for chili seedlings.