The high accuracy of industrial robots is the main aim of designers and manufacturers, one of the effective factors to get the goal is the stability of the robot structure, the determination of the structural dynamic characteristics is the main step to evaluate the performance also unlock the knowledge of amendment and improvement of the structure to get the optimum design.
In this paper, two methods were applied to evaluate the dynamic structural performance of three degrees of freedom parallel robot, firstly, experimental modal analysis was applied to a multi-model with different platform dimensions using a data acquisition system, the natural frequencies, and damping ratios for all models were obtained to be evaluated and correlated with the second method. The measured models were modeled using Solidworks software and exported to Ansys finite element (FE) software, the modeled systems were used to obtain natural frequencies, damping ratios, and mode shapes from frequency response curve (FRF) and modal analysis, the results of experimental and FEM work were correlated to evaluate the system performance and verify the accuracy of the two methods.
The results give a clear view to operators about the range of frequencies that must be avoided during the selection of machining operation, provide the scope of errors between the used methods, and supply a valuable guide to evaluate the quality of the structural integrity of the parallel robot.