Validation on Digital Twin of Six-Axis Robots with Modal Analysis

• Main Authors: CHEN, HUI-TING, 陳惠婷
• Other Authors: WU,TSUNG-LIANG
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/jenebm

碩士 === 國立高雄科技大學 === 機械與自動化工程系 === 107 === In this study, the goal of building a six-axis robot's Digital Twin is to achieve the off-line trajectory planning in machining operation by the ability of the digital avatar to synchronize with real state of the robot. In order to realize the equivalent model of the six-axis robot, the actual robot was subjected to impact test using Experimental Modal Analysis (EMA), after obtaining the frequency response function (FRF) by impact hammer and sensor, the modal analysis software (STAR 7) is used to perform curve fitting on FRF to obtain the natural frequency and mode shape. In finite element modal analysis, 3D model of the robot is analyzed by simulating boundary conditions of the actual fixed state. Finally, the results of two experiments are verified to confirm the correctness of model. This study found that boundary conditions have a significant impact on the results of modal analysis. For this reason, the experimental modal analysis conducted by six-axis robot from low-rigid aluminum extruded chassis to high-rigidity Vibration isolation table. In the finite element analysis, boundary conditions are set to fix the entire bottom surface and position of fixing screws and relax the joints for analysis, simulating the boundary condition setting close to the actual robot. In this way, by setting approach condition of boundary conditions, the difference between natural frequency values in the experimental and simulation results can be effectively improved.