Structural Design and Simulation Analysis of 4-DOF Heavy-Duty Robot

In order to meet the requirements of heavy-duty robots in the transportation industry, a 4-DOF heavy-duty robot with a load capacity up to 750kg is designed. We focused on the structural optimization design of the robot mechanical body. Firstly, the robot rigid body simulation model was created in the ADAMS software, and the robot's working space was obtained. Five typical poses of the robot were determined. Secondly, ANSYS Workbench software was used to carry out the static analysis of the whole machine. The components that do not comply with the strength and stiffness requirements were optimized so that the maximum deformation of the optimized robot is no more than 5mm. At last, the dynamic characteristics of the optimized robot were analyzed. The robot system was applied on stimulating force and produced displacement response. The harmonic response curve of the heavy-duty robot was obtained and the weak links could be found. After the part was rigidified, the arm was determined as the optimization object by modal analysis. Taking the frequency of the arm as the target, the range of arm mass and wall thickness is the constraint condition, and a set of optimal solutions was calculated by multi-objective optimization method. Dynamic stiffness of the optimized machine robot was obtained through harmonic response analysis, which shows that the maximum resonance peak of the whole machine in the x and z directions was reduced by about 40%, and the corresponding resonance frequency was increased by about 8.5%. Static stiffness performance and dynamic performance was significantly improved.