Design And Experimental Study On Automatic Feeding Device Of Lettuce Transplanter

At present,most of the small transplanters which are suitable for the current situation of transplanting operation in our country use manual operation in the feeding process,which has high operation cost and low operation efficiency,so it is urgent to use machinery instead of manual operation to improve the production mechanization.In this paper,the design of the automatic feeding device of the lettuce transplanter is completed.The device uses the gantry type transplanting arm to grab and disperse the lettuce seedlings from the densely planted tray and feed them into the rotating feeding cup,which lays the foundation for improving the efficiency of the transplanter.The main contents of this paper are as follows:(1)Research progress of transplanter and its key components at home and abroad.Referring to the relevant literature of the feeding device,studying and analyzing the structural characteristics of several typical feeding devices,considering the working environment and conditions of the transplanter in outdoor operation,giving up the use of pneumatic power and choosing the power to drive the feeding claw to complete the operation,according to the size and expected effect of the seedling in the hole tray,the feeding claw is designed as a two finger grasping structure,and the weight of the seedling,the moisture content of the substrate,etc The physical characteristics were measured to lay a foundation for the design of the feeding claw.(2)Determine the overall structure of automatic feeding device of lettuce transplanter.Determine the overall structure scheme of the automatic feeding device of the lettuce transplanter,use Solid Works 3D software to model the whole machine and complete the selection and verification of the key components and driving elements of the feeding device,including: the design of the driving components and the selection of the driving motor;the design of the feeding claw and its opening and closing guiding components.Finally,the prototype is processed and assembled for performance test.(3)The driving and control system design of automatic feeding device of lettuce transplanter was completed.Using Siemens The S7-200 PLC is used as the control host to complete the selection of hardware and software for the control system of the automatic feeding device of the transplanter,and to complete the preparation and debugging of the control program of the whole machine,It does not affect the operation effect.(4)The experimental research on automatic feeding device of lettuce transplanter was carried out.In this paper,8 × 16(128 points)pot lettuce was used as the experimental object.The single factor experiments were carried out to determine the range of the factors,which were the key parameters affecting the operation performance of the automatic feeding device of the lettuce transplanter,including the moisture content of the substrate,the angle of the feeding claw into the soil and the growth time of the pot.Then the three-dimensional quadratic regression orthogonal rotation combination experiment was carried out to optimize the parameters,and finally the moisture content of the substrate was determined 45%,the angle of the feeding claw as shown in the figure is 10°,and the growth time of the hole plate seedling is 25 days,which is the optimal experimental scheme.The success rate of grasping seedling under the second working parameters is 93.2%.