Research On Stiffness Performance Of RB20 Industrial Robot

In recent years,industrial robot technology has developed rapidly and is widely used in various industries,greatly improving production and manufacturing capabilities.However,the tandem robot has the problem of weak structural rigidity.In the process of machining,the change of the tool path eventually leads to the low processing quality and the chattering phenomenon.Therefore,there is great practical significance to improve the stiffness performance of industrial robots and improve the machining accuracy of industrial robots.There is no systematic solution to this problem in China.Therefore,this paper takes Guangzhou NC RB20 industrial robot as the research object.Based on the theoretical analysis,it uses Matlab's powerful computational simulation ability to do systematic research.In this paper,the modified D-H parameter model is used to establish the kinematics model of industrial robot,and the forward and inverse kinematics are solved and simulated.The results show that the solution of inverse kinematics is not unique.The differential transformation method is used to find the motion Jacobi matrix and the force Jacobi matrix of the robot.In order to avoid the singular space of industrial robots,it is necessary to solve the working space of the robot.This paper analyzes several usual methods for solving robot working space,but it is complex for 6-DOF robots and is not suitable.In this paper,the solid simulation model is established by Solidworks and SimMechanics together,and a reasonable driving module is added to obtain the working space of the robot.According to the traditional static stiffness model of the robot,the stiffness performance of the robot is related to the joint stiffness and the Jacobi matrix.The Jacobi matrix is related to the shape of the robot,so the influence of the shape and joint stiffness of the robot is studied.Analyze the robot transmission structure,and derive the stiffness calculation formula to calculate the stiffness value of each joint of the robot.Using the SimMechanics simulation model,the position and attitude of the robot are different,and the stiffness performance of the robot is also different.In order to quantitatively measure the stiffness performance of the robot,the stiffness performance index of the robot is introduced,and the influence of the joint angle and joint stiffness of the robot on the stiffness performance index is analyzed.In order to find the optimal attitude of the robot in the process,the stiffness performance of the robot is optimized.This paper uses the combination of genetic algorithm and Matlab genetic algorithm toolbox.With the maximum stiffness performance index as the optimization goal,the optimization model is established to obtain the optimal attitude based on the processing conditions and joint limit.The correctness of the optimization results was verified by the robot hole-turning experiment.Based on the above research,this paper establishes a set of system stiffness analysis and optimization methods.With computer simulation analysis,a reasonable optimization model is obtained,which improves the structural rigidity of the robot.For different processing conditions with this paper,the optimization results can be obtained by modifying the optimization model parameters.