Structural Analysis And Simulation Research Of 6R Mobile-rail Spraying Robot

In modern manufacturing,spraying robot plays an extremely important role,and its applications are more and more extensive.Based on the finite element analysis theory,the static analysis and modal analysis were carried out on the structure of the 6R spray robot,expecting to obtain the deformations and natural frequencies of the structure to provide the reference of meeting the requirement of absolute positioning accuracy.Based on the virtual prototype technology,the kinematics and dynamics theory modeling and simulation analysis were carried out.The simulation results and the precision measurement tests shew that the robot structure had good dynamic performance and could meet the requirements of the repeated positioning accuracy(±0.05mm)and absolute positioning accuracy(±1mm),which laid the foundation of achieving high-precision 6R mobile-rail spraying robot.The main contents of this paper are as follows:(1)According to the spraying robot's working features and design requirements,the related technical parameters and structural designing scheme was determined.And the 3D modeling software Solidworks was used not only to design all parts of the preliminary spraying robot but also to assemble them into a complete virtual prototype.For the spraying robot,not only were the different drivers compared,but also the parameters of motors and reducers were calculated and the drive system and power system of the various components were determined.(2)The FEA software ANSYS Workbench14.5 was used to do static analysis to the structure of the key components of the mobile-rail 6R spraying robot,with obtaining the stress and deformation distribution diagram of the key component structure,for checking whether the strength and stiffness of the robot can meet the requirement of the absolute positioning accuracy.Through the robot precision analysis,the theoretical repeated positioning accuracy was calculated,providing comparison with experiment results.By analyzing the modality of the key components of the robot,the natural frequencies and vibration modes were obtained,which would provide the reference basis for the robot to obtain safe and reliable structure and good dynamic performance and make it work in low noise and low vibration environment.(3)Based on the D-H coordinate method and the homogeneous transformation method,the kinematics model of the robot was established,and its positive solution and inverse solution based on the idea of substation were solved.By importing the parametric model of the robot into the ADAMS software in Parasolid format,the kinematic simulation of the robot was completed,obtaining the trajectory curve of the end actuator and the displacement,velocity and acceleration curves with time of the robot's joints,which made it convenient to understand the movement and performance of the robot.The Lagrangian method was used to establish the dynamic model to solve the multi-rigidbody dynamics equations of the robot system.The dynamic analysis of the robot was completed with ADAMS software,obtaining the torques of the key joints under certain working conditions,in order to improve the dynamic characteristics of the robot and the movement control required.(4)By using the laser tracking and measuring system,the tension meter and the micrometer,the measurement experiments of the spraying robot mechanical structure was done to obtain the absolute positioning accuracy which was 0.902 mm and repeated positioning accuracy which was 0.032 mm,satisfying the technique demands of absolute positioning accuracy of ±1mm and repeated positioning accuracy of ±0.05 mm.At the same time,the spraying trajectory motion experiments were carried out and some other robot mechanical parameters were measured.