Structural Analysis And Picking Path Planning Research Of Manipulator Arm Of Apple Picking Machine

With the rapid development of urbanization,my country’s population aging problem is significant,and a large number of rural population flows to cities,resulting in a decline in the rural labor force.There is a huge shortage of apple picking labor in my country.Therefore,vigorously developing apple harvesting machinery can solve the problem of labor shortage in rural areas in my country and reduce production costs at the same time.Although the application field of industrial robots is very extensive and the development is very mature,the development of the agricultural field is very slow due to the complex operating environment and higher requirements for machines.This paper takes apples as the picking object,analyzes and designs the structure of the manipulator,and studies the obstacle-free trajectory planning of the manipulator joint space and the collision-free path planning of the manipulator.According to the operation requirements of the manipulator,the design parameters of the manipulator are analyzed and determined,and the appropriate manipulator configuration is selected.The graphic method is used to determine the size range of the connecting rod,and Matlab software is used to initially optimize the size of each connecting rod of the manipulator to determine the initial size of the manipulator.The improved D-H parameter method is used to establish the coordinate system of the manipulator,and the influence of the joint angle and the length of the connecting rod on the picking range is analyzed.Based on the working space of the manipulator,the optimal solution for the size of the manipulator link is obtained by optimizing with the operability as the index.The dimensions of each link of the manipulator are known,and Solidworsk is used to draw the three-dimensional model of the manipulator’s components,and the static analysis of the arm and forearm of the manipulator is performed to verify whether the strength meets the requirements.Structural analysis of the robotic arm is carried out to reduce the weight and make it lightweight.By comparing a variety of interpolation algorithms: cubic polynomial,quintic polynomial,trapezoidal curve,S-shaped curve,etc.,the obstacle-free trajectory planning of the robotic arm joint space is studied under the obstacle-free environment.The analysis and research results show that the S-curve is the optimal interpolation method,which has the advantages of small velocity variation and stable acceleration variation.And use kinematics to verify the accuracy of the planning.Using the same obstacle environment,in the presence of obstacles,given the same starting point and end point(target point),in the same obstacle environment,carry out collision-free path planning for the robotic arm,with "the shortest path" and "the most convergent path".Fast” is the evaluation index.The ant colony algorithm and the RRT algorithm are analyzed and compared,and the results show that the RRT algorithm is better than the ant colony algorithm as a whole,and is more suitable for the collision-free trajectory planning of the manipulator.