Research On The Structrual Optimum Design And Trajectory Planning Of A Six-axis Manipulator

Manipulators are widely used in industrial production and play a key role in the development of human history.Unlike traditional types of industrial manipulators,modern new types of manipulators have many excellent characteristics,such as small weight,compact,high precision and more complex functions.In this paper,based on the design of a new type of industrial manipulator,the main application and industrial production line or outdoor handling industry,the main research contents are as follows:Firstly,the whole structure of the manipulator is designed.The designed manipulator has five degrees of freedom.Based on SoildWorks,the specific size parameters of the six joints of the manipulator are designed through the structure of Anno and other new generation manipulators.By calculating the relationship variables such as the joint torque and angular speed,the power and torque required for each joint driving motor are determined.Finally,the motor,reducer and mechanism are determined.Selection of actuators and bearings.Then the static and modal analysis of the designed manipulator is carried out when it is introduced into Ansys workbench.Then the stress and strain nephogram of the manipulator is processed to ensure the safety of the design of the manipulator.The weak link or redundant part of the manipulator can be determined.In the modal analysis,the first six modes of the manipulator can be obtained to ensure that the manipulator is in the process of operation.There will be no resonance.Finally,the Lagrange equation method is applied to verify the dynamic analysis of the whole machine model to ensure the rationality of the motion of the manipulator.Thirdly,by analyzing the static analysis cloud image of the manipulator,it is found that the safety performance of the manipulator is good and some structures are redundant.Therefore,in order to further improve the strength and stiffness of the designed manipulator and reduce its first three natural frequencies and other mechanical properties,multi-objective structural topology optimization is needed for structural components.Based on HyperMesh optimization,the weight coefficients of each sub-objective are determined by grey comprehensive correlation analysis method with the objective of maximizing static stiffness and minimizing the first three natural frequencies of the structure.After optimization,the optimized model is reconstructed according to the material density distribution cloud and iteration curve of the structure,and then the static and modal analysis of the reconstructed model is carried out.Compared with the results before optimization,it is found that the stress and strain of the optimized structure of the manipulator are reduced,which shows the rationality of the optimization algorithm.This provides a basis for the structural optimization of the same type.The theoretical reference basisis provided.Finally,the model of the robot arm is introduced into the ROS robot operating system to design the path planning.In the planning process,the improved RRT algorithm is used to optimize the obstacle avoidance analysis of the robot arm,and the optimal analysis and design of the position and posture of the robot arm can cROSs the obstacle smoothly to reach the target is realized.The speed of each joint in the process of obstacle avoidance is also analyzed.Change judgment shows that the manipulator runs smoothly and meets the working requirements.There are 64 papers,14 tables and 72 references in this paper.