Research On Balance System Of Heavy-duty Industrial Robot

With the development of robot technology rapidly,heavy-duty industrial robots have been used in logistics,automotive,aerospace and other fields widely,placed higher requirements on the robot's movement speed,workload and positioning accuracy.This dissertation designed a balance system for 210 kg heavy-duty industrial robot,and optimizes the relevant parameters of the balance system to reduce the driving torque of the arm joints and improved the robot's balance performance.Firstly,the kinematic equation of robot was established based on D-H parameter method.The robot motion space was determined by MATLAB simulation.At the same time,the dynamic modeling of robot was established based on Lagrange equation.The Joint torque of robot was solved by ADAMS,which provided reliable reference data for the design and optimization of the balance system.Secondly,a new spring-cylinder balance mechanism for heavy-duty industrial robots was designed in conjunction with the research on the conventional balance structure of robots.Mathematical analysis was performed on the important parameters such as the balance torque of the mechanism and the eccentric gravity of the robot.The mathematical model of the balance system was established.The maximum balance force output by the spring cylinder was solved by MATLAB to be 2.2 × 105 N.In order to improved the performance of the new spring-cylinder balance mechanism,the mathematical model of the balance system was optimized based on the FMINCON function.The spring stiffness coefficient was determined to be 55 mm finally.The distance between the spring-cylinder rotation axis and the boom rotation axis was 600 mm.The robot with spring cylinder balance mechanism was simulated by the ADAMS.The results showed that the balance system before optimization reduced the average driving torque of the robot boom joint by 27%,and the optimized balance system reduced the average driving torque of the robot boom joint by 36%.The correctness of the design of the spring cylinder balance system and the effectiveness of the balance system optimization were proved.Finally,in order to improve the load capacity of the new balance system,the robot arm was optimized based on genetic algorithm.The diameter of the robot arm is ? 129.8 mm and the length is 1028 mm.The robot arm was optimized by Hyper Works topology.The modal of the robot was analyzed.The simulation results showed that the deformation of the optimized arm under the same load was reduced by 53% and the mass was reduced by 12%.The simulation results indicated the effectiveness of the optimization of the arm parameters based on genetic algorithm.Similarly,the mass of the optimized robot arm was reduced by 12%,and the maximum deformation of the arm was reduced by 46%.The first six modes of the robot were improved,which showed that the optimization of the structure of the robot arm not only enhanced the rigidity,but also improved the stability of the robot movement.In this dissertation,a new spring-cylinder balance system that meets the requirements was designed.This dissertation verified the feasibility of the system in reduced the driving torque of the robot arm joint,which provided a reliable theoretical basis for the experimental study of the balance system of heavy-duty industrial robot,and could effectively improve the load characteristics of the heavy-duty industrial robot.