Design And Optimization Of Apple Picking Manipulator

China is the largest producer and consumer of fruits and vegetables in the world,and the output of fruits and vegetables ranks first in the world steadily.Fruit and vegetable harvesting is the most time-consuming and laborious link in the production chain.At present,most fruits and vegetables in China are picked manually,and the cost of picking accounts for 50%-70%of the cost.Mechanized harvesting of fruits and vegetables is of great significance to solve the problems of insufficient labor force,high production cost,low production efficiency and improve the market competitiveness of fruits and vegetables.In this paper,the structure design of apple harvesting manipulator is carried out.A kind of harvesting manipulator with Four-Degree-of-Freedom connecting rod manipulator is proposed,and a structure form of shearing end-effector is developed.The optimum structure scheme is determined by theoretical analysis.The simulation results show that the apple picking manipulator designed in this paper has good picking performance.Specific research contents are as follows:(1)The environmental characteristics of Apple plantations in China were analyzed.the planting spacing and row spacing of apple orchards were determined,the distribution characteristics and rules of apples on fruit trees were analyzed,the distribution area of apples on fruit trees was determined,and the physical performance parameters of picking objects were determined,which provided basic data and basis for the design of the overall scheme of picking manipulator.(2)According to the environmental characteristics of Apple plantation and the actual working requirements of apple harvesting manipulator,the driving mode of the harvesting manipulator was reasonably selected,the degree of freedom of the harvesting manipulator,the form of the end-effector and the structure mode of the harvesting manipulator were determined,and the overall design scheme of the apple harvesting manipulator was completed,which laid a foundation for the structural design of the harvesting manipulator.?(3)According to the overall design scheme of the apple picking manipulator and the physical characteristics of apple,the structure design of the end-effector of the picking manipulator is carried out in detail;according to the structure and shearing action requirements of the end-effector of the picking manipulator,the structure design of the end-effector of the picking manipulator is carried out;finally,according to the structure of the manipulator,the dynamic part of the manipulator is set up.Finally,the structure design of the picking manipulator is completed.(4)The correctness of the size of the picking manipulator arm and the stability of the manipulator operation were tested by atlas analysis and kinematics analysis.The results show that the working space of the picking manipulator can completely cover the distribution space of apples on fruit trees,and the size design of the manipulator is correct.The kinematics curves of the end-effector and the manipulator are smooth,the picking manipulator runs stably and the structure design is reasonable.(5)Finite element analysis of the load-bearing structure of the manipulator is carried out,and the load-bearing structure of the manipulator is optimized according to the analysis results and the requirements of picking accuracy of the manipulator.The maximum displacement of the manipulator after optimization.The shearing mechanism of the manipulator is analyzed,and the relationship between the cutting edge angle and the shearing force and the deformation of the tool is studied.Finally,the optimal tool angle is determined.According to the working environment of the picking manipulator and the physical characteristics of the picking object,a new type of apple picking manipulator with connecting rod manipulator and shearing end-effector was designed in this paper.The manipulator effectively improves the quality and efficiency of apple picking,reduces the labor intensity and cost of apple picking,and improves the market competitiveness of apple.The method used in this paper can provide reference for the development and research of other fruit and vegetable harvesting machinery and equipment.