Research On The Design And Control System Of The End Effector Of The Plug Seedling Transplanter

The transplanting of the tomato plug seedling in Xinjiang is mainly carried out by artificial transplanting,In the aspect of mechanization transplanting,semi-automatic transplanter is mainly used,The production efficiency and labor intensity of semi-automatic transplanting machine are still completely dependent on artificial work,which directly limits the popularization and application of tomato seedling transplanting technology in the field.Therefore,the development of fully automatic transplanter is an urgent problem to be solved.However,the end-effector of the automatic transplanter is the equipment directly in contact with the target crop.Therefore,it is very important to develop the end effector with high efficiency and stable performance for improving the survival rate and transplanting efficiency of the automatic transplanter.On the basis of fully studying and analyzing the existing end-effector technology of automatic transplanter at home and abroad,In order to solve the problems of high damage rate,low working efficiency and poor adaptability to different specifications of the end-effector of the automatic transplanting machine on the market,the following aspects of research are carried out in this paper:?1?In this paper,Xinjiang processed tomato was taken as the research object,and the compression characteristics of the substrate were analyzed,and the relation curve between the compression change and the pressure resistance under the constant compression speed 1mm/s was obtained.Based on the simulation of real clamping conditions,experiments were carried out on the compression characteristics of the seedling matrix under different compression rates,and the relationship between the compression variation and the pressure resistance was obtained at different compression speeds.In this paper,the related mechanics of the substrate of the plug seedling in the process of taking seedlings was analyzed,and the size parameters of the seedlings under the condition of low loss were obtained by setting up the model of the clamping action of the clamps of the seedlings to analyze the process of the taking of the seedlings and obtaining the requirements of the parameters of the size of the taken seedlings.Through the establishment of mathematical model,The analysis has come to a conclusion that the success rate and effect were mainly related to the angle of angle?,the change of clamping angle‘??',the friction coefficient?,the‘A_J'of the clamping area of the clamped piece and the change of the clamping angle‘??'.?2?In order to study the influence of three factors,such as the change of clamping angle,the moisture content of the substrate and the ratio of the substrate of the seedling,on the compressive strength of the substrate.the results of orthogonal design show that the sensitivity of each factor to the compressive capacity of the substrate is as follows:the ratio of the substrate of the disc>the change of the clamping angle>the moisture content,in order to improve the anti-pressure performance of the substrate.the better selection scheme is that the mixture ratio of the plug seedling substrate?peat:gravel:perlite?is 3:1:1,the change of the clamping angle of the pot seedling substrate is?2-3?degrees,and the water content is 65percent.?3?Based on the mechanical damage characteristics and clamping characteristics of the seedling matrix,combined with the transplanting characteristics and agronomic requirements of the seedlings in Xinjiang,the double-clip method of pneumatic entry-electric clamping was adopted to pick up the seedlings.According to the principle of eccentric rocker and slider mechanism,a simple and reliable end effector is designed.Parametric optimization design is implemented by using ADAMS virtual prototype software,and the structure parameters and seedling parameters of the end effector are determined so as to adapt to a variety of specifications,and meet the requirements of agricultural machinery and agronomy.?4?Based on the optimization results of the parameters of the terminal actuator,the 3D solid model of the end effector is established by using UG NX6.0 software,interference inspected and assembed,and the virtual prototype models of the clamping mechanism under the condition of cylinder shrinkage and protrusion are established respectively.The parameters of taking seedlings were obtained by adams kinematics simulation analysis and calculation:the depth of entry point‘Q₁'was 38mm,‘Q₂'was 36mm,‘??'=2.5°,and the distance of the screw from the installation position was 3.73 mm in the stage of adjusting the angle of the gripping finger.During the clamping stage,the screw nut is lowered from the mounting position to 14.83 mm,and the speed range is 12 to 14 mm.Furthermore select the parts of the clamping mechanism,manufacture the key mechanism,and complete the test platform of the mechanical system of the end-effector.?5?According to the analysis of the overall scheme design of the end-effector,in order to minimize the damage of the bowl and improve the survival rate of the transplanting,Requirements of the design of the control system was analized so as to design of the control system perfectly.In this chapter,the control flow graph of the taking seedling is described in detail,and the corresponding solution is put forward according to the control requirement.Then,the control hardware is selected for the problem of the seedling-taking control and the hole-in control of the end-effector and completed the pneumatic system design.?6?In the design part of the control system,it mainly designs the control scheme of the end-effector,selects the control hardware,draws the electrical schematic diagram of the end effector hardware,and uses Mitsubishi GX Works2 program to design the control program.Laying the groundwork for further research.