Vibration characteristics of a 6-DOF manipulator

MEI Yang-han1, ZHANG Rui-hao1, ZHANG Wen-long2, LIU Zhi-wei1, LIU Zi-miao1
(1.Department of Mechanical and Electrical Engineering, Dongguan Polytechnic, Dongguan 523808, China;
2.Dongguan Quality Testing, Dong Guan 523808, China）

Abstract: Aiming at the problem of serious vibration at the end of a new 6-DOF manipulator in the working process, the influence of each movement joint and the body of the manipulator on the vibration characteristics of the end were studied under different working postures. The simplified rigid flexible coupling dynamics model of the manipulator was constructed,the natural frequency characteristics of the body was obtained by simulation. Combined with mechanical vibration testing theory, the path transfer model based on excitation+monomer+ontology+end vibration was constructed, a modal test method combining the natural frequency test of the manipulator body with the vibration test of the single axis working mode was proposed. By using the AVANT MI-7008 dynamic spectrum analyzer, the start stop vibration frequency of each axis and the first and second order natural frequencies of manipulator body was extracted, and joints of the manipulator were avoided the resonance frequency range. The results indicate that the natural frequency test results are basically consistent with the simulation results, which verifies the feasibility of the scheme and provides an effective analysis method for improving the positioning accuracy and stability of the end of the manipulator.
Key words: natural frequency; modal test; vibration characteristics; manipulator body; six degree of freedom