| As people’s living standards speedily improving, demands for high quality of fruits andvegetables are increasing day by day. Grafting is the most effective way to overcomecontinuous plant diseases and low-temperature barriers. Automatic grafting robot instead ofmanual grafting is an efficient choice. Watermelon, for example, the national productionnearly66million tons in2010, automatic grafting can save60%labor force in the process ofgrafting with the speed as three times as manual grafting.This automatic grafting robot’s functional requirements were given on the basis ofcomparison between domestic and abroad research. Then seven main actions were proposedunder the functional requirements, which constructed the main structure of grafting robot. Inaddition the author finished experimental research on this prototype robot. Main work of thispaper can be summarized as follows:Compared to existing grafting methods selected the easy-mechanized operation,cut-pasted, as grafting method. Measured seedling height, diameters, cotyledon angle of500rootstock and scion seedlings. Researched on the mechanical properties of seedlings.Above study provide theoretical support for next mechanical design.Mechanical design mainly focused on positioning, chipping, moving, cutting,transportation, vibrating and sorting, chip pushing actions. Theoretical derivation of clipmovement on the vibrating face was done before modal and harmonious responseanalysis by software ANSYS12.0, vibration angle was selected by25°. Clip speed testverified the correctness of above analysis. Gripper design was based on theaforementioned characteristics of seedlings and stiffness of gripper springs that werecalculated.Mitsubishi FX1N-40MT was selected to control prototype machine. Control systemprogram was written by SFC language with GX-Developer. The whole program consistsof four subroutines: initialization, single step, back to the origin and automatic.The paper has finished experimental testing for this automatic grafting robot including:part-function test and continuous grafting experiments. Part-function test ensured thewhole system work reliable. The continuous experiment results were analyzed by SPSS,software results indicated that the average grafting success rate is92%and the system hasa working capability of720seedlings per hour. The experimental results also give us a setof proper seedling parameters that are suitable for grafting: rootstock diameter2.5-4.0(mm); scion diameter1.5-3.0(mm); rootstock stem and scion stem straight; angleof rootstock cotyledons close to180°. |
